CN1546205A

CN1546205A - Improved decarbonizing process by two-stage pressure-variable adsorption

Info

Publication number: CN1546205A
Application number: CNA200310104007XA
Authority: CN
Inventors: 宋宇文
Original assignee: Chengdu Tianli Chemical Engineering Technology Co Ltd
Current assignee: Chengdu Tianli Chemical Engineering Technology Co Ltd
Priority date: 2003-12-15
Filing date: 2003-12-15
Publication date: 2004-11-17
Anticipated expiration: 2023-12-15
Also published as: CN100493671C

Abstract

The invention is a kind of improved two-section pressure-swing sorption decarburizing method, which uses two pressure-swing sorption devices to operate in series, the synthesized ammonia transition gas enters the first section at first, the carbon dioxide in the transition gas is eliminated and extracts out the product carbon dioxide, the middle mixed gas gotten from the outlet of the first section sorption tower enter the second section, absorbs the impurities in the middle compound gas, the gas unabsorbed is carried into the next period as the product gas, the sorption tower of the first section passes through sorption A, two ends pressure equalizing and decreasing 2ED', carbon dioxide pressure decreasing D, two ends pressure equalizing and heightening2ER', finally pressure upgrading FR in a period, the sorption tower of the second section passes through the sorption A, pressure equalizing and decreasing ED, inverse discharging ED, vacuuming VC, pressure equalizing and upgrading ER, final pressure upgrading FR.

Description

A kind of improved two sections pressure swing adsorption decarbonization methods

One, technical field

The present invention relates to a kind of improved two sections pressure swing adsorption decarbonization methods, adopt improved two sections transformation adsorbed gas isolation technics, belong to transformation adsorbed gas separation field.

Two, background technology

We know, in the synthetic ammonia urea production process, carbon dioxide in the conversion gas need be purified, also need the hydrogen in the conversion gas, nitrogen separation are come out simultaneously, satisfy synthetic ammonia (or connection alcohol) urea production requirement, therefore, in fact decarbonizing urea is exactly purifying carbon dioxide and separation of hydrogen, nitrogen from conversion gas.The present invention also is applied in liquefied ammonia production, methanol production and the soda ash production.

At present, adopt two-stage pressure swing adsorption from conversion gas, to remove the method for carbon dioxide, have disclosed patent documentation and document announcement both at home and abroad.As the open CN1235862A of Chinese patent, CN1248482A, employing two-stage pressure swing adsorption apparatus such as CN1357404A remove the carbon dioxide in the conversion gas, this method is under suitable pressure, carbon dioxide in the conversion gas can be purified and be used for urea production, the rate of recovery of above-mentioned prior art hydrogen is generally 95-98% (rising with adsorptive pressure improves), the rate of recovery of carbon monoxide is generally 80-87% (rising with adsorptive pressure improves), the rate of recovery of nitrogen is generally 85-89% (rising with adsorptive pressure improves), the rate of recovery of carbon dioxide is generally 65-70%, synthetic ammonia power consumption 80-138 degree per ton (rising with adsorptive pressure reduces), open for above-mentioned Chinese patent, when adsorptive pressure is less than or equal to 0.8MPa (G), this method is compared with the wet method decarburization and can be reduced investment outlay and energy consumption, has greater advantage.Chinese patent open CN1347747A, CN1342509A, CN1334135A, CN1334136A etc. also adopt two-stage pressure swing adsorption apparatus to remove carbon dioxide in the conversion gas, these four Chinese patents are open openly compare significantly with first three Chinese patent reduce investment outlay, the rate of recovery of energy consumption and raising available gas, suitable pressure limit is very wide.The present invention is to the improvement of carbon dioxide plant in two sections transformation adsorbing and removing conversion gas such as Chinese patent disclosure CN1347747A, CN1342509A, CN1334135A, CN1334136A, further reduces investment outlay, the rate of recovery of energy consumption and raising available gas.

Three, summary of the invention

It is reasonable to the purpose of this invention is to provide a kind of investment economy, and two sections pressure swing adsorption decarbonization methods that operating cost is very low adopt the combination of different equipment and adsorbent.Make it to have and compared with prior art save operating cost, reduce the available gas loss of device.

Technical solution of the present invention is as follows: the present invention adopts the two-stage pressure swing adsorption apparatus serial operation, synthetic-ammonia transformation gas at first enters first section pressure swing adsorption gas separation device, carbon dioxide in the conversion gas partly is removed and carries the dense product carbon dioxide that is, the middle gaseous mixture that obtains from first section pressure swing adsorption gas separation device adsorption tower outlet enters second section pressure swing adsorption gas separation device, impurity absorption in the middle gaseous mixture is got off, the gas that is not adsorbed enters next workshop section as product gas, first section pressure swing adsorption gas separation device adsorption tower experiences absorption A successively in a cycle period, two ends drop pressure 2ED ', product carbon dioxide step-down D, two ends boost pressure 2ER ', the FR processing step that finally boosts, second section pressure swing adsorption gas separation device adsorption tower experience absorption A successively in a cycle period, drop pressure ED, the contrary BD of putting, vacuumize VC, boost pressure ER, the FR processing step finally boosts.

Increase forward drop pressure ED after first section pressure swing adsorption gas separation device adsorption tower process cycles step absorption A.

Increase after first section pressure swing adsorption gas separation device adsorption tower process cycles step product carbon dioxide step-down D and purge the CP step.

Increase after first section pressure swing adsorption gas separation device adsorption tower process cycles step product carbon dioxide step-down D and vacuumize the VC step.

In first section pressure swing adsorption gas separation device adsorption tower process cycles step, the available VC step substitute products carbon dioxide step-down D step that vacuumizes is to form another basic scheme.

First section pressure swing adsorption gas separation device adsorption tower process cycles step two ends drop pressure 2ED ' increases gaseous mixture step-down D1 step afterwards.

First section pressure swing adsorption gas separation device adsorption tower process cycles step two ends drop pressure 2ED ' increases displacement P step afterwards, and working off one's feeling vent one's spleen of adsorption tower of displacement enters other system or emptying.

When first section pressure swing adsorption gas separation device adsorption tower replaced the P step, another adsorption tower of working off one's feeling vent one's spleen to first section pressure swing adsorption gas separation device of displacement adsorption tower boosted, and carried out the displacement gas PR that boosts simultaneously before the boost pressure 2ER ' of two ends.

Increase displacement P step after first section pressure swing adsorption gas separation device adsorption tower process cycles step gaseous mixture step-down D1, working off one's feeling vent one's spleen of adsorption tower of displacement enters other system or emptying.

Increase after second section pressure swing adsorption gas separation device adsorption tower process cycles step drop pressure ED and reclaim the RG step, increase simultaneously two sections gas lifts and press the 2ER step after first section pressure swing adsorption gas separation device adsorption tower process cycles step vacuumizes the VC step, above-mentioned second section pressure swing adsorption gas separation device adsorption tower reclaims between RG step and two sections gas lifts pressures of the first section pressure swing adsorption gas separation device adsorption tower 2ER step and is connected by surge tank V1.

In second section pressure swing adsorption gas separation device adsorption tower process cycles step, replace against putting the BD step, to form another basic scheme with reclaiming the RG step.

In first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment.

In first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide replacement gas intermediate buffering jar V4, put into product carbon dioxide intermediate buffering jar V2 again, put into product carbon dioxide buffer jar V3 at last, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment, and the gas of product carbon dioxide replacement gas intermediate buffering jar V4 is put into product carbon dioxide replacement gas surge tank V5 by pressure or Flow-rate adjustment.

In first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, put into product carbon dioxide gas holder V at last, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment.

In first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide replacement gas intermediate buffering jar V4, next puts into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, put into product carbon dioxide gas holder V at last, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment, and the gas of product carbon dioxide replacement gas intermediate buffering jar V4 is put into product carbon dioxide replacement gas surge tank V5 by pressure or Flow-rate adjustment.

The adsorbent that loads from down to up in the first stage pressure swing adsorption apparatus adsorption tower is activated alumina and Kiselgel A, and the adsorbent of filling is a Kiselgel A in the second stage pressure swing adsorption apparatus adsorption tower, or molecular sieve.

The mean concentration of carbon dioxide was 7～15% (V) during the first stage pressure swing adsorption apparatus adsorption step was worked off one's feeling vent one's spleen.

The invention solves problems of the prior art.Compared with prior art save operating cost, reduce the available gas loss of device.

Four, description of drawings:

Fig. 1 is the processing step working procedure table of the embodiment of the invention 1 first stage pressure swing adsorption apparatus adsorption tower.

Fig. 2 is the processing step working procedure table of the embodiment of the invention 1 second stage pressure swing adsorption apparatus adsorption tower.

Fig. 3 is the process chart of the embodiment of the invention 1.

Fig. 4 is the processing step working procedure table of the embodiment of the invention 2 first stage pressure swing adsorption apparatus adsorption towers.

Fig. 5 is the processing step working procedure table of the embodiment of the invention 2 second stage pressure swing adsorption apparatus adsorption towers.

Fig. 6 is the process chart of the embodiment of the invention 2.

Fig. 7 is the processing step working procedure table of the embodiment of the invention 3 first stage pressure swing adsorption apparatus adsorption towers.

Fig. 8 is the processing step working procedure table of the embodiment of the invention 3 second stage pressure swing adsorption apparatus adsorption towers.

Fig. 9 is the process chart of inventive embodiments 3.

Figure 10 is the processing step working procedure table of the embodiment of the invention 4 first stage pressure swing adsorption apparatus adsorption towers.

Figure 11 is the processing step working procedure table of the embodiment of the invention 4 second stage pressure swing adsorption apparatus adsorption towers.

Figure 12 is the process chart of the embodiment of the invention 4.

Figure 13 is the processing step working procedure table of the embodiment of the invention 5 first stage pressure swing adsorption apparatus adsorption towers.

Figure 14 is the processing step working procedure table of the embodiment of the invention 5 second stage pressure swing adsorption apparatus adsorption towers.

Figure 15 is the process chart of inventive embodiments 5.

Five, the specific embodiment:

Unstripped gas of the present invention is a synthetic-ammonia transformation gas, comprises that with coal, natural gas, oil and other be the synthetic-ammonia transformation gas of raw material, its typical table composed as follows:

Component	??H ₂	??N ₂	??CO ₂	???CO	??CH ₁	??O ₂+Ar	Total sulfur	??H ₂O (vapour)
Component	??H ₂	??N ₂	??CO ₂	???CO	??CH ₁	??O ₂+Ar	Total sulfur	??H ₂O (vapour)	Concentration (%) (V)	46～62	?0～20	17～38	?0.3～8	??1～2	??≤0.8	????≤100mg/Nm ³	Saturated

The present invention adopts the two-stage pressure swing adsorption apparatus operation, synthetic-ammonia transformation gas at first enters first section pressure swing adsorption gas separation device, carbon dioxide in the conversion gas partly is removed and carries the dense product carbon dioxide that is, the high-load of product carbon dioxide can reach 99.99% (V), the middle gaseous mixture that obtains from first section pressure swing adsorption gas separation device adsorption tower outlet enters second section pressure swing adsorption gas separation device, impurity absorption in the middle gaseous mixture is got off, and the gas that is not adsorbed enters next workshop section as product gas.The mean concentration of carbon dioxide was 7～15% (V) (determining concrete practical operation concentration according to the carbon dioxide content in the synthetic-ammonia transformation gas) during the first stage pressure swing adsorption apparatus adsorption tower was worked off one's feeling vent one's spleen, the adsorbent that loads from down to up in the adsorption tower is activated alumina and Kiselgel A, the carbon dioxide (mean concentration is 7～15% (V)) that second stage pressure swing adsorption apparatus is used for that first stage pressure swing adsorption apparatus is worked off one's feeling vent one's spleen is removed to the level of next workshop section's needs, or with hydrogen purification to 99.999%, the absorption profit of filling is a Kiselgel A in the adsorption tower, making pure hydrogen is molecular sieve, and each adsorption tower of two-stage pressure swing adsorption apparatus experiences following steps successively in a circulation.

First stage pressure swing adsorption apparatus:

(1) absorption A

The conversion pneumatic transmission is gone into to be in the adsorption tower charging aperture of adsorption step, adsorbent in the adsorption tower optionally adsorbs the water in the conversion gas successively, component such as organic sulfur and inorganic sulfur and carbon dioxide, Xi Fu partial CO 2 and be difficult for the carbon monoxide of absorption not, methane, nitrogen, components such as hydrogen flow out from the port of export and enter the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, As time goes on, adsorbent water, the total amount of component such as organic sulfur and inorganic sulfur and carbon dioxide constantly increases, when the adsorbents adsorb said components is saturated, stop air inlet, this moment, absorption finished.Gas concentration lwevel preferably is controlled at 7～15% (V) in working off one's feeling vent one's spleen, and can certainly be controlled at gas concentration lwevel in other scopes.

(2) two ends drop pressure 2ED

After absorption A finishes, hydrogen in the dead space gas in the adsorption tower, nitrogen gas concn is higher and gas concentration lwevel is lower, and this part hydrogen, nitrogen need be recycled on the one hand, and gas concentration lwevel needs to improve in the adsorption tower on the other hand, for this reason, must emit the gas in the adsorption tower and carry out depressurization desorption.The gradation of dead space gas is discharged from the adsorption tower two ends and is entered this section and finished the corresponding adsorption tower of evacuation step and boost, gas of every row is just all pressed once, along with the increase of all pressing number of times, the gas concentration lwevel in exit, adsorption tower two ends constantly increases, and hydrogen, nitrogen obtain recycling simultaneously.All press number of times to finish the gas concentration lwevel decision in exit, adsorption tower two ends, back by adsorptive pressure and absorption, generally all press number of times preferably can satisfy and all press the gas concentration lwevel that finishes adsorption tower exit, back greater than 75% (V), when carrying out above-mentioned drop pressure, preferably carry out simultaneously at two ends, also can be earlier drop pressure forward, later stage before drop pressure balance is forward carried out reverse drop pressure to same adsorption tower simultaneously, purpose is to improve gas concentration lwevel and recovery hydrogen in the adsorption tower, nitrogen, also can carry out forward drop pressure earlier, before the two pressure tower balances, stop forward drop pressure, and then carry out reverse drop pressure, the previous case can improve the adsorbent utilization rate.When carrying out drop pressure, the gas of emitting from the bottom should be less than the gas of emitting from the top.Adsorption tower drop pressure 2ED step of the present invention and common adsorption tower drop pressure ED step are different, common adsorption tower drop pressure ED step gas is to emit from the port of export of adsorption tower, be the said forward drop pressure of the present invention, emit and adsorption tower drop pressure 2ED gas of the present invention is import and export two ends from adsorption tower.

After absorption A finishes, adsorption tower is when drop pressure, and preceding all the pressure several times adopted forward drop pressure ED, then all presses several times or all presses for the last time and adopt two ends drop pressure 2ED, after drop pressure finished, the product gas concentration lwevel still can satisfy the urea production requirement.

(3) gaseous mixture step-down D1

After drop pressure 2ED finishes, in order further to improve gas concentration lwevel in the adsorption tower, forward the mist in the adsorption tower is emitted simultaneously with reverse step-down, the tolerance of putting into is decided by the concentration that the adsorption tower carbon dioxide will reach, also can be earlier forward forward step-down after reverse step-down or the reverse step-down earlier after the step-down, but forward can improve the adsorbent utilization rate simultaneously with reverse step-down.After drop pressure 2ED finished, gas concentration lwevel met the demands in the adsorption tower, can not carry out this step of gaseous mixture step-down D1.

(4) product carbon dioxide replacement P

After gaseous mixture step-down D1 or two ends drop pressure 2ED end, when gas concentration lwevel still can not meet the demands in the adsorption tower, can be after the power-equipment pressurization with a part of product carbon dioxide, enter adsorption tower from the adsorption tower bottom inlet, replace other component along the absorption direction by adsorption tower, displace directly emptying of implication, also can enter another adsorption tower and boost and reclaim hydrogen and nitrogen gas and carbon dioxide, displacement pressure is that two ends drop pressure 2ED or gaseous mixture step-down D1 finish back adsorption tower internal pressure.When displacement P step consecutive hours, can not establish surge tank after the power-equipment, when displacement P step is discontinuous, then after the power-equipment surge tank must be set.After gaseous mixture step-down D1 or two ends drop pressure 2ED end, when the product gas concentration lwevel reached requirement, product carbon dioxide replacement P step can not wanted.

(5) product carbon dioxide step-down D

After displacement P step finishes, the product carbon dioxide is at first put into product carbon dioxide replacement gas intermediate buffering jar V4, after the balance, put into product carbon dioxide intermediate buffering jar V2 again, after the balance, put into product carbon dioxide buffer jar V3 at last, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment, and the gas of product carbon dioxide replacement gas intermediate buffering jar V4 is put into product carbon dioxide replacement gas surge tank V5 by pressure or Flow-rate adjustment.Product carbon dioxide step-down D can along absorption direction, also can against absorption direction.When adsorptive pressure is low, can directly put into gas holder V or all press with surge tank after put into gas holder V again.Before if product carbon dioxide step-down D step is implemented, the pressure in the adsorption tower is lower, then shouldn't product carbon dioxide step-down D step, and directly extract adsorbent carbon dioxide out with vavuum pump.

After gaseous mixture step-down D1 or the end of two ends drop pressure 2ED step, the product carbon dioxide is at first put into product carbon dioxide intermediate buffering jar V2, after the balance, put into product carbon dioxide buffer jar V3 again, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment.When adsorptive pressure is low, can directly put into gas holder V or all press with surge tank after put into gas holder V again.Before if product carbon dioxide step-down D step is implemented, the pressure in the adsorption tower is lower, then shouldn't product carbon dioxide step-down D step, and directly extract adsorbent carbon dioxide out with vavuum pump.

(6) vacuumize VC

After product carbon dioxide step-down D finished, adsorbent carbon dioxide being released with vavuum pump from the adsorption tower bottom entered product carbon dioxide buffer jar V3, when adsorptive pressure is low, can enter gas holder V.After product carbon dioxide step-down D finishes, do not vacuumize the VC step if do not adopt, can adopt to purge the CP step, purging the gas that adopts is dry product carbon dioxide or other gas.

(7) two sections gas lifts are pressed 2ER

Vacuumize after VC finishes, the gas that enters the gaseous mixture surge tank after utilizing the equal pressure drop ED of the second stage pressure swing adsorption apparatus adsorption tower to finish boosts to finishing the adsorption tower that vacuumizes step from the first stage pressure swing adsorption apparatus adsorption tower port of export.Increase the available gas rate of recovery that this step can improve device.

(8) the displacement gas PR that boosts

After two sections gas lifts press 2ER to finish, utilize the exit gas of other adsorption tower displacement of this stage pressure swing adsorption apparatus P step that adsorption tower is boosted.

(9) two ends boost pressure 2ER '

Displacement gas boosts after PR finishes, and the gas that utilizes this section two ends drop pressure 2ED step to discharge enters adsorption tower from entrance end, makes the adsorption tower pressure that progressively raises, and two ends boost pressure 2ER ' equates with the number of times of two ends drop pressure 2ED.The gas of each two ends boost pressure 2ER ' is from the two ends drop pressure 2ED gas of different adsorption towers.This section adsorption tower two ends boost pressure 2ER ' step and common boost pressure ER step are different, common adsorption tower boost pressure ER step gas is that the port of export from adsorption tower enters, and enters and this section adsorption tower two ends boost pressure 2ER ' step gas is import and export two ends from adsorption tower.

(10) FR that finally boosts

After two ends boost pressure 2ER ' step finishes, utilize the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and adsorption tower is boosted,, also can utilize unstripped gas that the adsorption tower of finishing equal voltage rise ER step is boosted until being raised to adsorptive pressure from the top.

Second stage pressure swing adsorption apparatus

(1) absorption A

The adsorption tower that first stage pressure swing adsorption apparatus is in adsorption step is worked off one's feeling vent one's spleen and is sent into the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower is absorbing carbon dioxide optionally, and components such as the carbon monoxide of difficult absorption, methane, nitrogen, hydrogen are discharged the compression section that enters synthetic ammonia from the port of export.As time goes on, adsorbent total carbon dioxide capacity constantly increases, when the adsorbents adsorb carbon dioxide is saturated, stop air inlet, this moment, absorption finished, gas concentration lwevel is controlled according to producing needs in working off one's feeling vent one's spleen, minimum can arrive that tens ppm work off one's feeling vent one's spleen also can be with hydrogen purification to 99.999% (V).

(2) drop pressure ED

After absorption finished, hydrogen in the dead space gas in the adsorption tower, nitrogen gas concn were higher, and this part hydrogen, nitrogen need be recycled.The gradation of dead space gas is discharged from adsorption tower outlet and is entered this section and finished the corresponding adsorption tower of evacuation step and boost, and gas of every row is just all pressed once, and along with the increase of all pressing number of times, the gas concentration lwevel in adsorption tower exit constantly increases.All press number of times to finish the gas concentration lwevel decision in adsorption tower exit, back by adsorptive pressure and absorption.

(3) reclaim RG

After drop pressure ED finishes, gas in the adsorption tower forward, or it is reverse, or earlier along putting the contrary surge tank of putting in back, after this again the surge tank and first stage pressure swing adsorption apparatus have been finished vacuumizing the boost adsorption tower of PR step of VC or displacement gas and be communicated with, hydrogen, the nitrogen of second stage pressure swing adsorption apparatus has been reclaimed.

(4) the contrary BD of putting

After reclaiming the RG end,, must gas be reduced to normal pressure against the absorption direction if gas pressure is higher in the adsorption tower; If after reclaiming the RG end, gas pressure is very low in the adsorption tower, can cancel the contrary BD step of putting.

(5) vacuumize VC

Reclaim RG or contrary put BD and finish after, from the adsorption tower bottom with vavuum pump with the emptying of releasing of adsorbent carbon dioxide and other component, make adsorbent obtain regeneration.

(6) boost pressure ER

After vacuumizing end, the gas that utilizes the drop pressure step to discharge enters from the port of export and to finish the adsorption tower that vacuumizes step, makes the adsorption tower pressure that progressively raises, and boost pressure equates with the number of times of drop pressure.The gas of each boost pressure is from the drop pressure gas of different adsorption towers

(7) FR that finally boosts

After boost pressure finishes, utilize the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and adsorption tower is boosted, until being raised to adsorptive pressure from the top.

Embodiments of the invention 1:

Unstripped gas of the present invention is a synthetic-ammonia transformation gas, comprises that with coal, natural gas, oil and other be the synthetic-ammonia transformation gas of raw material.

The synthetic-ammonia transformation gas of present embodiment is composed as follows:

Component H2 N2 CO2 CO CH4 O2+Ar total sulfur water (vapour)

Concentration V% 52～53 17～18 25～28≤1～6 1～2≤0.8 150mg/Nm3 is saturated

Temperature :≤40 ℃

Pressure: 0.8MPa (G)

As shown in Figure 3, adsorption tower A～I is totally 9 composition first stage pressure swing adsorption apparatus, and the adsorbent that loads from down to up in the adsorption tower is followed successively by activated alumina and Kiselgel A, moves single tower absorption and all presses program five times; Adsorption tower a～g is totally 7 composition second stage pressure swing adsorption apparatus, and the adsorbent of filling is a Kiselgel A in the adsorption tower, moves single tower absorption and all presses program four times.V is the first stage pressure swing adsorption apparatus product carbon dioxide gas holder, and P1 and P2 are respectively first section and the second stage pressure swing adsorption apparatus vavuum pump.Present embodiment first stage pressure swing adsorption apparatus is purified to carbon dioxide more than 98.5% (V), be used for urea synthesis, the second stage pressure swing adsorption apparatus effect is that working off one's feeling vent one's spleen of first stage pressure swing adsorption apparatus further purified, make in the hydrogen, nitrogen of the second stage pressure swing adsorption apparatus adsorption tower a～g upper end outlet gas concentration lwevel less than 0.2% (V), to satisfy the needs of next step operation of synthetic ammonia.

Conversion gas enters the adsorption tower that first stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower optionally adsorbs the components such as water, organic sulfur, inorganic sulfur and carbon dioxide in the conversion gas successively, components such as the carbon monoxide of Xi Fu partial CO 2 and difficult absorption, methane, nitrogen, hydrogen are not discharged from the port of export and are entered the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower is absorbing carbon dioxide optionally, and components such as the carbon monoxide of difficult absorption, methane, nitrogen, hydrogen are discharged from the port of export and entered compression section.The adsorption tower of first stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, 2E1D ' all falls in two ends one, 2E2D ' all falls in two ends two, 2E3D ' all falls in two ends three, 2E4D ' all falls in two ends four, 2E5D ' all falls in two ends five, product carbon dioxide replacement P, product carbon dioxide step-down D, vacuumize VC, the displacement gas PR that boosts, two sections gas lifts are pressed 2ER, isolate I, two ends five all rise 2E5R ', two ends four all rise 2E4R ', two ends three all rise 2E3R ', two ends two all rise 2E2R ', two ends one all rise 2E1R ', the FR pressure swing adsorption technique step of finally boosting, first stage pressure swing adsorption apparatus is the product carbon dioxide at the gas that product carbon dioxide step-down D step obtains, the adsorption tower of second stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, one all falls E1D, two all fall E2D, three all fall E3D, four all fall E4D, reclaim RG, the contrary BD of putting, vacuumize VC, four all rise E4R, three all rise E3R, two all rise E2R, one all rises E1R, the FR pressure swing adsorption technique step of finally boosting, the gaseous mixture that second stage pressure swing adsorption apparatus is in the adsorption tower outlet discharge of adsorption step is mainly nitrogen, hydrogen product wherein also contains a spot of carbon monoxide and methane.Be example with the A tower now, contrast Fig. 1 and Fig. 3 illustrate the processing step of the present embodiment first stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

At this moment, the A tower has been finished the FR step of finally boosting, open sequencing valve 1A, 2A, conversion gas enters adsorption tower A through pipeline G11, in the A adsorption tower, adsorbent optionally adsorbs the water in the conversion gas successively, organic sulfur, component such as inorganic sulfur and carbon dioxide, Xi Fu partial CO 2 and be difficult for the carbon monoxide of absorption not, methane, nitrogen, components such as hydrogen flow out through sequencing valve 2A from the port of export and enter the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, As time goes on, adsorbent water, the total amount of component such as organic sulfur and inorganic sulfur and carbon dioxide constantly increases, when the adsorbents adsorb said components is saturated, stop air inlet, this moment, absorption finished, and closed sequencing valve 1A, 2A, gas concentration lwevel is controlled at 10～13% (V) in working off one's feeling vent one's spleen.

(2) the equal voltage drop step in the two ends first time is called for short two ends one and all falls 2E1D '

After absorption finishes, open sequencing valve 3A, 3C, 7A and 7C, the gas in the A tower enters the C tower through pipeline G13 and G17 the C tower is carried out boost pressure in two ends (being called for short 2E1R '), after A and C pressure tower are in a basic balance, closes sequencing valve 3A, 7C.

(3) the equal voltage drop step in the two ends second time is called for short two ends two and all falls 2E2D '

After 2E1D ' end all falls in two ends one, open sequencing valve 4A, 4D, 7A and 7D, gas in the A tower enters the D tower through pipeline G14 and G17 the D tower is carried out two ends secondary boost pressure (being called for short 2E2R '), after A and D pressure tower are in a basic balance, closes sequencing valve 4D, 7A and 7D.

(4) the equal voltage drop step in two ends for the third time is called for short two ends three and all falls 2E3D '

After 2E2D ' end all falls in two ends two, open sequencing valve 4E, 11A and 11E, gas in the A tower enters the E tower through pipeline G14 and G111 the E tower is carried out three boost pressures in two ends (being called for short 2E3R '), after A and E pressure tower are in a basic balance, closes sequencing valve 4A, 4E and 11E.

(5) the 4th equal voltage drop step in two ends are called for short two ends four and all fall 2E4D '

After 2E3D ' end all falls in two ends three, open sequencing valve 5A, 5F and 11F, gas in the A tower enters the F tower through pipeline G15 and G111 the F tower is carried out four boost pressures in two ends (being called for short 2E4R '), after A and F pressure tower are in a basic balance, closes sequencing valve 5F, 11A and 11F.

(6) the 5th equal voltage drop step in two ends are called for short two ends five and all fall 2E5D '

After 2E4D ' end all falls in two ends four, open sequencing valve 5G, 12A and 12G, gas in the A tower enters the G tower through pipeline G15 and G112 the G tower is carried out five boost pressures in two ends (being called for short 2E5R '), after A and G pressure tower are in a basic balance, closes sequencing valve 5A, 5G, 12A and 12G.

(7) product carbon dioxide replacement P

After 2E5D ' end all falls in two ends five, open sequencing valve 8A, 10A, KV-12a and 6I, the compressed machine C of product carbon dioxide this moment, surge tank V6, pipeline G18 enter adsorption tower A from the import of A tower bottom, along the absorption direction adsorption tower A is replaced, the gas that is displaced enters adsorption tower I and boosts, when carbon dioxide reaches the regulation requirement in displacing implication, close sequencing valve 8A, 10A, KV-12a and 6I, displacement pressure is 0.08MPa (G).

(8) product carbon dioxide step-down D

After product carbon dioxide replacement P finishes, open sequencing valve 8A, KV13b earlier, product carbon dioxide gas holder V is put in the product carbon dioxide step-down in the A tower,, close sequencing valve 8A, KV13b when the pressure of A tower during near gas holder V pressure.

(9) vacuumize VC

After product carbon dioxide step-down D finishes, open sequencing valve 9A, the carbon dioxide in the tower being released from the A tower bottom through pipeline G19, vavuum pump P1 enters product carbon dioxide gas holder V, vacuumize end after, close sequencing valve 9A.

(10) the displacement gas PR that boosts

After vacuumizing the VC end, open sequencing valve 8C, 10C, KV-12a and 6A, the compressed machine C of product carbon dioxide this moment, surge tank V6, pipeline G18 enter adsorption tower C from the import of A tower bottom, along the absorption direction adsorption tower C is replaced, the gas that is displaced enters adsorption tower A and boosts, when carbon dioxide reaches the regulation requirement in displacing implication, close sequencing valve 8C, 10C, KV-12a and 6A.

(11) two sections gas lifts are pressed 2ER

Displacement gas boosts after PR finishes, and opens sequencing valve KV-15 and 10A, and the gas in the surge tank V1 enters the A tower A tower is boosted, and after the pressure of surge tank V1 and adsorption tower A is in a basic balance, boosts after the end, closes sequencing valve KV-15 and 10A.

(12) isolate I

After two sections gas lifts press 2ER to finish, close all sequencing valves of A tower.Also can cancel isolation I step by increasing by 9 sequencing valves.

(13) the 5th equal voltage rise steps in two ends are called for short two ends five and all rise 2E5R '

After isolating the I end, open sequencing valve 5A, 5E, 12A and 12E, gas in the E tower enters the A tower through pipeline G15 and G112 the A tower is carried out five boost pressures in two ends (being called for short 2E5R '), after A and E pressure tower are in a basic balance, closes sequencing valve 5A, 5E, 12A and 12E.

(14) the 4th equal voltage rise steps in two ends are called for short two ends four and all rise 2E4R '

After two ends five all rise 2E5R ' end, open sequencing valve 5A, 5F, 11A and 11F, gas in the F tower enters the A tower through pipeline G15 and G111 the A tower is carried out four boost pressures in two ends (being called for short 2E4R '), after A and F pressure tower are in a basic balance, closes sequencing valve 5A, 5F and 11F.

(15) the equal voltage rise step in two ends for the third time is called for short two ends three and all rises 2E3R '

After two ends four all rise 2E4R ' end, open sequencing valve 4A, 4G and 11G, gas in the G tower enters the A tower through pipeline G14 and G111 the A tower is carried out three boost pressures in two ends (being called for short 2E3R '), after A and G pressure tower are in a basic balance, closes sequencing valve 4G, 11A and 11G.

(16) the equal voltage rise step in the two ends second time is called for short two ends two and all rises 2E2R '

After two ends three all rise 2E3R ' end, open sequencing valve 4H, 7A and 7H, gas in the H tower enters the A tower through pipeline G14 and G17 the A tower is carried out two ends secondary boost pressure (being called for short 2E2R '), after A and H pressure tower are in a basic balance, closes sequencing valve 4A, 4H and 7H.

(17) the equal voltage rise step in the two ends first time is called for short two ends one and all rises 2E1R '

After two ends two all rise 2E2R ' end, open sequencing valve 3A, 3I and 7I, gas in the I tower enters the A tower through pipeline G13 and G17 the A tower is carried out boost pressure in two ends (being called for short 2E1R '), after A and I pressure tower are in a basic balance, closes sequencing valve 3I, 7A and 7I.

(18) FR that finally boosts

Sequencing valve KV-12 is opened after all rising 2E1R ' end in two ends one, utilizes the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and boosts from the top to the A tower, when the A pressure tower rises near adsorptive pressure, closes sequencing valve KV-12,3A.Also can be with unstripped gas to the A tower FR that finally boosts.

So far, the A tower has been finished a circulation, can enter next circulation again.B～I adsorption tower is the same with the circulation step of A tower, just staggers mutually on the time, sees Fig. 1.

Be example with a tower now, contrast Fig. 2 and Fig. 3 illustrate the processing step of the present embodiment second stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

At this moment, the a tower has been finished the FR step of finally boosting, open sequencing valve 1a, 2a, middle gaseous mixture enters adsorption tower a through pipeline G21, in a adsorption tower, adsorbent optionally adsorbs the components such as carbon dioxide of first stage pressure swing adsorption apparatus in working off one's feeling vent one's spleen, Xi Fu amounts of carbon dioxide and be difficult for the carbon monoxide of absorption not, methane, nitrogen, components such as hydrogen flow out the compression section that enters synthetic ammonia from the port of export through sequencing valve 2a, As time goes on, adsorbent total carbon dioxide capacity constantly increases, when the adsorbents adsorb carbon dioxide is saturated, the gas concentration lwevel of working off one's feeling vent one's spleen is controlled at below 0.2% (V), closes sequencing valve 1a, 2a stops air inlet, this moment, absorption finished, and closed sequencing valve 1a, 2a.

(2) for the first time equal voltage drop step is called for short one and all falls E1D

After absorption A finishes, open sequencing valve 3a, 3c, the gas in a tower enters the c tower through pipeline G23 to carry out one to the c tower and all rises, and after a and c pressure tower are in a basic balance, closes sequencing valve 3a.

(3) for the second time equal voltage drop step is called for short two and all falls E2D

One all falls after E1D finishes, and opens sequencing valve 4a, 4d, and the gas in a tower enters the d tower through pipeline G24 to carry out two to the d tower and all rise, and after a and d pressure tower are in a basic balance, closes sequencing valve 4d.

(4) equal for the third time voltage drop step is called for short three and all falls E3D

Two all fall after E2D finishes, and open sequencing valve 4e, and the gas in a tower enters the e tower through pipeline G24 to carry out three to the e tower and all rise, and after a and e pressure tower are in a basic balance, close sequencing valve 4a.

(5) the 4th equal voltage drop step are called for short four and all fall E4D

Three all fall after E3D finishes, and open sequencing valve 5a, 5f, and the gas in a tower enters the f tower through pipeline G25 to carry out four to the f tower and all rise, and after a and f pressure tower are in a basic balance, close sequencing valve 5f.

(6) reclaim RG

Four all fall after E4D finishes, and open sequencing valve KV-15a, and the gas in a tower is forward put into surge tank V1, make the gas pressure in a tower drop to the pressure near surge tank V1, after finishing, close sequencing valve KV-15a.Also can gas be put into surge tank V1 from the bottom of adsorption tower a.

(7) the contrary BD of putting

After reclaiming the RG end, open sequencing valve 7a,, when the gas in a tower drops near normal pressure, close sequencing valve 7a the reverse emptying of the gas in a tower.

(8) vacuumize VC

Contrary put BD and finish after, open sequencing valve 8a, through pipeline G27, vavuum pump P2 from a tower bottom the emptying of releasing of the gas in the tower, vacuumize end after, close sequencing valve 8a.

(9) the 4th equal voltage rise steps are called for short four and all rise E4R

Vacuumize after VC finishes, open sequencing valve 5a, 5c, the gas in the c tower enters a tower through pipeline G25 to carry out four to a tower and all rises, and after c and a pressure tower are in a basic balance, closes sequencing valve 5a, 5c.

(10) equal for the third time voltage rise step is called for short three and all rises E3R

Four all rise E4R finish after, open sequencing valve 4a, 4d, the gas in the d tower enters a tower through pipeline G24 to carry out three to a tower and all rises, and after d and a pressure tower are in a basic balance, closes sequencing valve 4d.

(11) for the second time equal voltage rise step is called for short two and all rises E2R

Three all rise E3R finish after, open sequencing valve 4e, the gas in the e tower enters a tower through pipeline G24 to carry out two to a tower and all rises, and after e and a pressure tower are in a basic balance, closes sequencing valve 4e, 4a.

(12) for the first time equal voltage rise step is called for short one and all rises E1R

Two all rise E2R finish after, open sequencing valve 3a, 3f, the gas in the f tower enters a tower through pipeline G23 to carry out one to a tower and all rises, and after f and a pressure tower are in a basic balance, closes sequencing valve 3f.

(13) FR that finally boosts

One all rises E1R finish after, open sequencing valve KV-16, utilize the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and boost from the top to a tower, when a pressure tower rises to adsorptive pressure, close sequencing valve KV 16,3a.

So far, a tower has been finished a circulation, can enter next circulation again.B～g adsorption tower is the same with the circulation step of A tower, just staggers mutually on the time, sees Fig. 2.

The present embodiment result is 98.5% (V) for the product carbon dioxide purity, and gas concentration lwevel is less than 0.2% (V) in product hydrogen, the nitrogen, and hydrogen recovery rate is greater than 98.5% (V), and rate of recovery of nitrogen is greater than 95% (V), and recovery rate of CO 2 is greater than 70% (V).

For present embodiment, adopt particular adsorbent combination of the present invention, under the identical situation of other condition (adsorptive pressure is 0.8MPa (G), conversion gas composition and temperature, sorption cycle time, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span), synthetic ammonia decarburization power consumption per ton on average descends 15%, the investment of decarburization original equipment can save 2.5%, and the rate of recovery of available gas improves about 0.5% (V).According to the Ammonia Production arts demand, also can be with more than the hydrogen purification to 99.999% (V) in present embodiment second stage pressure swing adsorption apparatus.In the second stage pressure swing adsorption apparatus processing step of present embodiment, also can cancel and reclaim the RG step, but the rate of recovery of available gas (hydrogen, nitrogen and carbon monoxide) will reduce, and when all pressures number of times of second stage pressure swing adsorption apparatus is more than enough, also can cancel the contrary BD step of putting.At this, do not describe in detail one by one.

Embodiments of the invention 2:

Condition such as conversion gas composition, temperature, adsorbent kind and the ratio of present embodiment, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span and embodiment 1 are in full accord, and the adsorptive pressure of present embodiment is 2.0MPa (G).

As shown in Figure 6, adsorption tower A～J is totally 10 composition first stage pressure swing adsorption apparatus, and the adsorbent that loads from down to up in the adsorption tower is followed successively by activated alumina and Kiselgel A, moves single tower absorption and all presses program seven times; Adsorption tower a～i is totally 9 composition second stage pressure swing adsorption apparatus, and the adsorbent of filling is a Kiselgel A in the adsorption tower, moves single tower absorption and all presses program six times, utilizes vacuum pipeline G27 that adsorption tower is vacuumized by vavuum pump P2.P1 and P2 are respectively first section and the second stage pressure swing adsorption apparatus vavuum pump.Present embodiment first stage pressure swing adsorption apparatus is purified to carbon dioxide more than 99.5% (V), be used for urea synthesis, the second stage pressure swing adsorption apparatus effect is that working off one's feeling vent one's spleen of first stage pressure swing adsorption apparatus further purified, make in the hydrogen, nitrogen of the second stage pressure swing adsorption apparatus adsorption tower a～i upper end outlet gas concentration lwevel less than 0.2% (V), to satisfy the needs of next step operation of synthetic ammonia.

Conversion gas enters the adsorption tower that first stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower optionally adsorbs the components such as water, organic sulfur, inorganic sulfur and carbon dioxide in the conversion gas successively, components such as the carbon monoxide of Xi Fu partial CO 2 and difficult absorption, methane, nitrogen, hydrogen are not discharged from the port of export and are entered the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower is absorbing carbon dioxide optionally, and components such as the carbon monoxide of difficult absorption, methane, nitrogen, hydrogen are discharged from the port of export and entered compression section.The adsorption tower of first stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, 2E1D ' all falls in two ends one, 2E2D ' all falls in two ends two, 2E3D ' all falls in two ends three, 2E4D ' all falls in two ends four, 2E5D ' all falls in two ends five, 2E6D ' all falls in two ends six, 2E7D ' all falls in two ends seven, product carbon dioxide step-down D, vacuumize VC, two sections gas lifts are pressed 2ER, two ends seven all rise 2E7R ', two ends six all rise 2E6R ', two ends five all rise 2E5R ', two ends four all rise 2E4R ', two ends three all rise 2E3R ', two ends two all rise 2E2R ', two ends one all rise 2E1R ', the FR pressure swing adsorption technique step of finally boosting, first stage pressure swing adsorption apparatus is the product carbon dioxide at the gas that product carbon dioxide step-down D step obtains, the adsorption tower of second stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, one all falls E1D, two all fall E2D, three all fall E3D, four all fall E4D, five all fall E5D, six all fall E6D, reclaim RG, the contrary BD of putting, vacuumize VC, six all rise E6R, five all rise E5R, four all rise E4R, three all rise E3R, two all rise E2R, one all rises E1R, the FR pressure swing adsorption technique step of finally boosting, the gaseous mixture that second stage pressure swing adsorption apparatus is in the adsorption tower outlet discharge of adsorption step is mainly nitrogen, hydrogen product wherein also contains a spot of carbon monoxide and methane.Be example with the A tower now, contrast Fig. 4 and Fig. 6 illustrate the processing step of the present embodiment first stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

At this moment, the A tower has been finished the FR step of finally boosting, open sequencing valve 1A, 2A, conversion gas enters adsorption tower A through pipeline G11, in the A adsorption tower, adsorbent optionally adsorbs the water in the conversion gas successively, organic sulfur, component such as inorganic sulfur and carbon dioxide, Xi Fu partial CO 2 and be difficult for the carbon monoxide of absorption not, methane, nitrogen, components such as hydrogen flow out through sequencing valve 2A from the port of export and enter the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, As time goes on, adsorbent water, the total amount of component such as organic sulfur and inorganic sulfur and carbon dioxide constantly increases, when the adsorbents adsorb said components is saturated, stop air inlet, this moment, absorption finished, and closed sequencing valve 1A, 2A, gas concentration lwevel is controlled at 8～13% (V) in working off one's feeling vent one's spleen.

After 2E1D ' end all falls in two ends one, open sequencing valve 4A, 4D and 7D, gas in the A tower enters the D tower through pipeline G14 and G17 the D tower is carried out two ends secondary boost pressure (being called for short 2E2R '), after A and D pressure tower are in a basic balance, closes sequencing valve 4D, 7A and 7D.

(7) the 6th equal voltage drop step in two ends are called for short two ends six and all fall 2E6D '

After 2E5D ' end all falls in two ends five, open sequencing valve 6A, 6H and 12H, gas in the A tower enters the H tower through pipeline G16 and G112 the H tower is carried out six boost pressures in two ends (being called for short 2E6R '), after A and H pressure tower are in a basic balance, closes sequencing valve 6A, 6H, 12A and 12H.

(8) the 7th equal voltage drop step in two ends are called for short two ends seven and all fall 2E7D '

After 2E6D ' end all falls in two ends six, open sequencing valve 6A, 6I, 8A and 8I, gas in the A tower enters the I tower through pipeline G16 and G18 the I tower is carried out seven boost pressures in two ends (being called for short 2E7R '), after A and I pressure tower are in a basic balance, closes sequencing valve 6A, 6I, 8A and 8I.

(9) product carbon dioxide step-down D

After 2E7D ' end all falls in two ends seven, open sequencing valve 8A, KV13b earlier, product carbon dioxide intermediate buffering jar V2 is put in product carbon dioxide step-down in the A tower, when the pressure of A tower during near V2 pressure, close sequencing valve KV13b, open sequencing valve KV13c again, product carbon dioxide buffer jar V3 is put in the product carbon dioxide step-down in the A tower, when the pressure of A tower during, close sequencing valve 8A and KV13c near V3 pressure.

(10) vacuumize VC

After product carbon dioxide step-down D finishes, open sequencing valve 9A, the carbon dioxide in the tower being released from the A tower bottom through pipeline G19, vavuum pump P1 enters product carbon dioxide buffer jar V3, vacuumize end after, close sequencing valve 9A.

(11) two sections gas lifts are pressed 2ER

After vacuumizing the VC end, open sequencing valve KV-15 and 10A, the gas in the surge tank V1 enters the A tower A tower is boosted, and after the pressure of surge tank V1 and adsorption tower A is in a basic balance, boosts after the end, closes sequencing valve KV-15 and 10A.

(12) the 7th equal voltage rise steps in two ends are called for short two ends seven and all rise 2E7R '

After two sections gas lifts press 2ER to finish, open sequencing valve 6A, 6C, 8A and 8C, gas in the C tower enters the A tower through pipeline G16 and G18 the A tower is carried out seven boost pressures in two ends (being called for short 2E7R '), after A and C pressure tower are in a basic balance, closes sequencing valve 6C, 8A and 8C.

(13) the 6th equal voltage rise steps in two ends are called for short two ends six and all rise 2E6R '

After two ends seven all rise 2E7R ' end, open sequencing valve 6D, 12A and 12D, gas in the D tower enters the A tower through pipeline G16 and G112 the A tower is carried out six boost pressures in two ends (being called for short 2E6R '), after A and D pressure tower are in a basic balance, closes sequencing valve 6A, 6D and 12D.

(14) the 5th equal voltage rise steps in two ends are called for short two ends five and all rise 2E5R '

After two ends six all rise 2E6R ' end, open sequencing valve 5A, 5E and 12E, gas in the E tower enters the A tower through pipeline G15 and G112 the A tower is carried out five boost pressures in two ends (being called for short 2E5R '), after A and E pressure tower are in a basic balance, closes sequencing valve 5E, 12A and 12E.

(15) the 4th equal voltage rise steps in two ends are called for short two ends four and all rise 2E4R '

After two ends five all rise 2E5R ' end, open sequencing valve 5F, 11A and 11F, gas in the F tower enters the A tower through pipeline G15 and G111 the A tower is carried out four boost pressures in two ends (being called for short 2E4R '), after A and F pressure tower are in a basic balance, closes sequencing valve 5A, 5F and 11F.

(16) the equal voltage rise step in two ends for the third time is called for short two ends three and all rises 2E3R '

(17) the equal voltage rise step in the two ends second time is called for short two ends two and all rises 2E2R '

(18) the equal voltage rise step in the two ends first time is called for short two ends one and all rises 2E1R '

(19) FR that finally boosts

Sequencing valve KV-12 is opened after all rising 2E1R ' end in two ends one, utilizes the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and boosts from the top to the A tower, when the A pressure tower rises near adsorptive pressure, closes sequencing valve KV-12,3A.Also can be with unstripped gas to the A tower FR that finally boosts.So far, the A tower has been finished a circulation, can enter next circulation again.B～J adsorption tower is the same with the circulation step of A tower, just staggers mutually on the time, sees Fig. 4 and Fig. 6.

Be example with a tower now, contrast Fig. 5 and Fig. 6 illustrate the processing step of the present embodiment second stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

(5) the 4th equal voltage drop step are called for short four and all fall E4D

(6) the 5th equal voltage drop step are called for short five and all fall E5D

Four all fall after E4D finishes, and open sequencing valve 5a, 5g, and the gas in a tower enters the g tower through pipeline G25 to carry out five to the g tower and all rise, and after a and f pressure tower are in a basic balance, close sequencing valve 5f.

(7) the 6th equal voltage drop step are called for short six and all fall E6D

Five all fall after E5D finishes, and open sequencing valve 6a, 6h, and the gas in a tower enters the h tower through pipeline G26 to carry out six to the h tower and all rise, and after a and h pressure tower are in a basic balance, close sequencing valve 6a and 5h.

(8) reclaim RG

Six all fall after E6D finishes, and open sequencing valve KV-15a, and the gas in a tower is forward put into surge tank V1, make the gas pressure in a tower drop to the pressure near surge tank V1, after finishing, close sequencing valve KV-15a.Also can gas be put into surge tank V1 from the bottom of adsorption tower a.

(9) the contrary BD of putting

(10) vacuumize VC

(11) the 6th equal voltage rise steps are called for short six and all rise E6R

Vacuumize after VC finishes, open sequencing valve 6a, 6c, the gas in the c tower enters a tower through pipeline G26 to carry out six to a tower and all rises, and after c and a pressure tower are in a basic balance, closes sequencing valve 6a, 6c.

(12) the 5th equal voltage rise steps are called for short five and all rise E5R

Six all rise E6R finish after, open sequencing valve 5a, 5d, the gas in the d tower enters a tower through pipeline G25 to carry out five to a tower and all rises, and after d and a pressure tower are in a basic balance, closes sequencing valve 5d.

(13) the 4th equal voltage rise steps are called for short four and all rise E4R

Five all rise E5R finish after, open sequencing valve 5a, 5e, the gas in the e tower enters a tower through pipeline G25 to carry out four to a tower and all rises, and after e and a pressure tower are in a basic balance, closes sequencing valve 5a, 5e.

(14) equal for the third time voltage rise step is called for short three and all rises E3R

Four all rise E4R finish after, open sequencing valve 4a, 4f, the gas in the f tower enters a tower through pipeline G24 to carry out three to a tower and all rises, and after f and a pressure tower are in a basic balance, closes sequencing valve 4f.

(15) for the second time equal voltage rise step is called for short two and all rises E2R

Three all rise E3R finish after, open sequencing valve 4g, the gas in the g tower enters a tower through pipeline G24 to carry out two to a tower and all rises, and after g and a pressure tower are in a basic balance, closes sequencing valve 4e, 4a.

(16) for the first time equal voltage rise step is called for short one and all rises E1R

Two all rise E2R finish after, open sequencing valve 3a, 3h, the gas in the h tower enters a tower through pipeline G23 to carry out one to a tower and all rises, and after h and a pressure tower are in a basic balance, closes sequencing valve 3h.

(17) FR that finally boosts

One all rises E1R finish after, open sequencing valve KV-16, utilize the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and boost from the top to a tower, when a pressure tower rises to adsorptive pressure, close sequencing valve KV-16,3a.

So far, a tower has been finished a circulation, can enter next circulation again.B～i adsorption tower is the same with the circulation step of a tower, just staggers mutually on the time, sees Fig. 5 and Fig. 6.

For present embodiment, adopt particular adsorbent combination of the present invention, under the identical situation of other condition (adsorptive pressure is 2.0MPa (G), conversion gas composition and temperature, sorption cycle time, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span), synthetic ammonia decarburization power consumption per ton on average descends 10%, the investment of decarburization original equipment can save 5%, and the rate of recovery of available gas improves about 0.5% (V).According to the Ammonia Production arts demand, also can be with more than the hydrogen purification to 99.999% (V) in present embodiment second stage pressure swing adsorption apparatus.In the second stage pressure swing adsorption apparatus processing step of present embodiment, also can cancel and reclaim the RG step, but the rate of recovery of available gas (hydrogen, nitrogen and carbon monoxide) will reduce, and when all pressures number of times of second stage pressure swing adsorption apparatus is more than enough, also can cancel the contrary BD step of putting.At this, do not describe in detail one by one.

Embodiments of the invention 3:

Condition such as the conversion gas composition of present embodiment, temperature, adsorbent kind, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span and embodiment 1 are in full accord, and the adsorptive pressure of present embodiment is 3.0MPa (G).

As shown in Figure 9, adsorption tower A～K is totally 11 composition first stage pressure swing adsorption apparatus, and the adsorbent that loads from down to up in the adsorption tower is followed successively by activated alumina and Kiselgel A, moves single tower absorption and all presses program 9 times; Adsorption tower a～j is totally 10 composition second stage pressure swing adsorption apparatus, and the adsorbent of filling is a Kiselgel A in the adsorption tower, moves single tower absorption and all presses program seven times, utilizes vacuum pipeline G27 that adsorption tower is vacuumized by vavuum pump P2.P2 is the second stage pressure swing adsorption apparatus vavuum pump.Present embodiment first stage pressure swing adsorption apparatus is purified to carbon dioxide more than 98.5% (V), be used for urea synthesis, the second stage pressure swing adsorption apparatus effect is that working off one's feeling vent one's spleen of first stage pressure swing adsorption apparatus further purified, make in the hydrogen, nitrogen of the second stage pressure swing adsorption apparatus adsorption tower a～j upper end outlet gas concentration lwevel less than 0.2% (V), to satisfy the needs of next step operation of synthetic ammonia.

Conversion gas enters the adsorption tower that first stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower optionally adsorbs the components such as water, organic sulfur, inorganic sulfur and carbon dioxide in the conversion gas successively, components such as the carbon monoxide of Xi Fu partial CO 2 and difficult absorption, methane, nitrogen, hydrogen are not discharged from the port of export and are entered the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower is absorbing carbon dioxide optionally, and components such as the carbon monoxide of difficult absorption, methane, nitrogen, hydrogen are discharged from the port of export and entered compression section.The adsorption tower of first stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, 2E1D ' all falls in two ends one, 2E2D ' all falls in two ends two, 2E3D ' all falls in two ends three, 2E4D ' all falls in two ends four, 2E5D ' all falls in two ends five, 2E6D ' all falls in two ends six, 2E7D ' all falls in two ends seven, 2E8D ' all falls in two ends eight, 2E9D ' all falls in two ends nine, product carbon dioxide step-down D, purge CP, two sections gas lifts are pressed 2ER, two ends nine all rise 2E9R ', isolate I, two ends eight all rise 2E8R ', two ends seven all rise 2E7R ', two ends six all rise 2E6R ', two ends five all rise 2E5R ', two ends four all rise 2E4R ', two ends three all rise 2E3R ', two ends two all rise 2E2R ', two ends one all rise 2E1R ', the FR pressure swing adsorption technique step of finally boosting, first stage pressure swing adsorption apparatus is the product carbon dioxide at the gas that product carbon dioxide step-down D step obtains, the adsorption tower of second stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, one all falls E1D, two all fall E2D, three all fall E3D, four all fall E4D, five all fall E5D, six all fall E6D, seven all fall E7D, reclaim RG, the contrary BD of putting, vacuumize VC, seven all rise E7R, six all rise E6R, five all rise E5R, four all rise E4R, three all rise E3R, two all rise E2R, one all rises E1R, the FR pressure swing adsorption technique step of finally boosting, the gaseous mixture that second stage pressure swing adsorption apparatus is in the adsorption tower outlet discharge of adsorption step is mainly nitrogen, hydrogen product wherein also contains a spot of carbon monoxide and methane.Be example with the A tower now, contrast Fig. 7 and Fig. 9 illustrate the processing step of the present embodiment first stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

At this moment, the A tower has been finished the FR step of finally boosting, open sequencing valve 1A, 2A, conversion gas enters adsorption tower A through pipeline G11, in adsorption tower A, adsorbent optionally adsorbs the water in the conversion gas successively, organic sulfur, component such as inorganic sulfur and carbon dioxide, Xi Fu partial CO 2 and be difficult for the carbon monoxide of absorption not, methane, nitrogen, components such as hydrogen flow out through sequencing valve 2A from the port of export and enter the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, As time goes on, adsorbent water, the total amount of component such as organic sulfur and inorganic sulfur and carbon dioxide constantly increases, when the adsorbents adsorb said components is saturated, stop air inlet, this moment, absorption finished, and closed sequencing valve 1A, 2A, gas concentration lwevel is controlled at 7～10% (V) in working off one's feeling vent one's spleen.

After absorption finishes, open sequencing valve 3A, 3C, 11A and 11C, the gas in the A tower enters the C tower through pipeline G13 and G111 the C tower is carried out boost pressure in two ends (being called for short 2E1R '), after A and C pressure tower are in a basic balance, closes sequencing valve 3A, 11C.

After 2E1D ' end all falls in two ends one, open sequencing valve 4A, 4D and 11D, gas in the A tower enters the D tower through pipeline G14 and G111 the D tower is carried out two ends secondary boost pressure (being called for short 2E2R '), after A and D pressure tower are in a basic balance, closes sequencing valve 4D, 11A and 11D.

After 2E2D ' end all falls in two ends two, open sequencing valve 4E, 12A and 12E, gas in the A tower enters the E tower through pipeline G14 and G112 the E tower is carried out three boost pressures in two ends (being called for short 2E3R '), after A and E pressure tower are in a basic balance, closes sequencing valve 4A, 4E and 12E.

After 2E3D ' end all falls in two ends three, open sequencing valve 5A, 5F and 12F, gas in the A tower enters the F tower through pipeline G15 and G112 the F tower is carried out four boost pressures in two ends (being called for short 2E4R '), after A and F pressure tower are in a basic balance, closes sequencing valve 5F, 12A and 12F.

After 2E4D ' end all falls in two ends four, open sequencing valve 5G, 13A and 13G, gas in the A tower enters the G tower through pipeline G15 and G113 the G tower is carried out five boost pressures in two ends (being called for short 2E5R '), after A and G pressure tower are in a basic balance, closes sequencing valve 5A, 5G and 13G.

After 2E5D ' end all falls in two ends five, open sequencing valve 6A, 6H and 13H, gas in the A tower enters the H tower through pipeline G16 and G113 the H tower is carried out six boost pressures in two ends (being called for short 2E6R '), after A and H pressure tower are in a basic balance, closes sequencing valve 6H, 13A and 13H.

After 2E6D ' end all falls in two ends six, open sequencing valve 6I, 8A and 8I, gas in the A tower enters the I tower through pipeline G16 and G18 the I tower is carried out seven boost pressures in two ends (being called for short 2E7R '), after A and I pressure tower are in a basic balance, closes sequencing valve 6A, 6I and 8I.

(9) the 8th equal voltage drop step in two ends are called for short two ends eight and all fall 2E8D '

After 2E7D ' end all falls in two ends seven, open sequencing valve 7A, 7J and 8J, gas in the A tower enters the J tower through pipeline G17 and G18 the J tower is carried out eight boost pressures in two ends (being called for short 2E8R '), after A and J pressure tower are in a basic balance, closes sequencing valve 7J, 8A and 8J.

(10) the 9th equal voltage drop step in two ends are called for short two ends nine and all fall 2E9D '

After 2E8D ' end all falls in two ends eight, open sequencing valve 7K, 9A and 9K, gas in the A tower enters the K tower through pipeline G17 and G19 the K tower is carried out nine boost pressures in two ends (being called for short 2E9R '), after A and K pressure tower are in a basic balance, closes sequencing valve 7A, 7K and 9K.

(11) product carbon dioxide step-down D

After 2E9D ' end all falls in two ends nine, open sequencing valve KV-14a earlier, product carbon dioxide intermediate buffering jar V2 is put in product carbon dioxide step-down in the A tower, when the pressure of A tower during near V2 pressure, close sequencing valve KV14a, open sequencing valve KV14 again, product carbon dioxide buffer jar V3 is put in the product carbon dioxide step-down in the A tower, when the pressure of A tower during, close sequencing valve KV-14 near V3 pressure.

(12) purge CP

After product carbon dioxide step-down D finishes, open sequencing valve 10A, KV-16b and KV-14b, through pipeline G19 and G10 the carbon dioxide in the A tower is purged out and to enter product carbon dioxide buffer jar V3, when the gas concentration lwevel that purges out can not satisfy production requirement, close sequencing valve KV-14b, open sequencing valve KV-16a, with the gaseous mixture emptying of producing by boasting, after purging the CP end, close sequencing valve 9A, 10A, KV-16b and KV-16a.

(13) two sections gas lifts are pressed 2ER

After purging the CP end, open sequencing valve KV-15 and 10A, the gas in the surge tank V1 enters the A tower A tower is boosted, and after the pressure of surge tank V1 and adsorption tower A is in a basic balance, closes sequencing valve KV-15 and 10A.

(14) the 9th equal voltage rise steps in two ends are called for short two ends nine and all rise 2E9R '

After two sections gas lifts press 2ER to finish, open sequencing valve 7A, 7B, 9A and 9B, gas in the B tower enters the A tower through pipeline G19 and G17 the A tower is carried out nine boost pressures in two ends (being called for short 2E9R '), after A and B pressure tower are in a basic balance, closes sequencing valve 7B, 9A and 9B.

(15) isolate I

After two ends nine all rise 2E9R ' end, close all sequencing valves of A tower.Also can cancel isolation I step by increasing by 11 sequencing valves.

(16) the 8th equal voltage rise steps in two ends are called for short two ends eight and all rise 2E8R '

After isolating I and finishing, open sequencing valve 7A, 7C, 8A and 8C, the gas in the C tower enters the A tower through pipeline G17 and G18 the A tower is carried out eight boost pressures in two ends (being called for short 2E8R '), after A and C pressure tower are in a basic balance, close sequencing valve 7A,, 7C and 8C.

(17) the 7th equal voltage rise steps in two ends are called for short two ends seven and all rise 2E7R '

After two ends eight all rise 2E8R ' end, open sequencing valve 6A, 6D and 8D, gas in the D tower enters the A tower through pipeline G16 and G18 the A tower is carried out seven boost pressures in two ends (being called for short 2E7R '), after A and D pressure tower are in a basic balance, closes sequencing valve 6D, 8A and 8D.

(18) the 6th equal voltage rise steps in two ends are called for short two ends six and all rise 2E6R '

After two ends seven all rise 2E7R ' end, open sequencing valve 6E, 13A and 13E, gas in the E tower enters the A tower through pipeline G16 and G113 the A tower is carried out six boost pressures in two ends (being called for short 2E6R '), after A and E pressure tower are in a basic balance, closes sequencing valve 6A, 6E and 13E.

(19) the 5th equal voltage rise steps in two ends are called for short two ends five and all rise 2E5R '

After two ends six all rise 2E6R ' end, open sequencing valve 5A, 5F and 13F, gas in the F tower enters the A tower through pipeline G15 and G113 the A tower is carried out five boost pressures in two ends (being called for short 2E5R '), after A and F pressure tower are in a basic balance, closes sequencing valve 5F, 13A and 13F.

(20) the 4th equal voltage rise steps in two ends are called for short two ends four and all rise 2E4R '

After two ends five all rise 2E5R ' end, open sequencing valve 5G, 12A and 12G, gas in the G tower enters the A tower through pipeline G15 and G112 the A tower is carried out four boost pressures in two ends (being called for short 2E4R '), after A and G pressure tower are in a basic balance, closes sequencing valve 5A, 5G and 12G.

(21) the equal voltage rise step in two ends for the third time is called for short two ends three and all rises 2E3R '

After two ends four all rise 2E4R ' end, open sequencing valve 4A, 4H and 12H, gas in the H tower enters the A tower through pipeline G14 and G112 the A tower is carried out three boost pressures in two ends (being called for short 2E3R '), after A and H pressure tower are in a basic balance, closes sequencing valve 4H, 12A and 12H.

(22) the equal voltage rise step in the two ends second time is called for short two ends two and all rises 2E2R '

After two ends three all rise 2E3R ' end, open sequencing valve 4I, 11A and 11I, gas in the I tower enters the A tower through pipeline G14 and G111 the A tower is carried out two ends secondary boost pressure (being called for short 2E2R '), after A and I pressure tower are in a basic balance, closes sequencing valve 4A, 4I and 11I.

(23) the equal voltage rise step in the two ends first time is called for short two ends one and all rises 2E1R '

After two ends two all rise 2E2R ' end, open sequencing valve 3A, 3J and 11J, gas in the J tower enters the A tower through pipeline G13 and G111 the A tower is carried out boost pressure in two ends (being called for short 2E1R '), after A and J pressure tower are in a basic balance, closes sequencing valve 3J, 11A and 11J.

(24) FR that finally boosts

Sequencing valve KV-12 is opened after all rising 2E1R ' end in two ends one, utilizes the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and boosts from the top to the A tower, when the A pressure tower rises near adsorptive pressure, closes sequencing valve KV-12,3A.Also can be with unstripped gas to the A tower FR that finally boosts.So far, the A tower has been finished a circulation, can enter next circulation again.B～K adsorption tower is the same with the circulation step of A tower, just staggers mutually on the time, sees Fig. 7 and Fig. 9.

Be example with a tower now, contrast Fig. 8 and Fig. 9 illustrate the processing step of the present embodiment second stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

(5) the 4th equal voltage drop step are called for short four and all fall E4D

(6) the 5th equal voltage drop step are called for short five and all fall E5D

(7) the 6th equal voltage drop step are called for short six and all fall E6D

Five all fall after E5D finishes, and open sequencing valve 6a, 6h, and the gas in a tower enters the h tower through pipeline G26 to carry out six to the h tower and all rise, and after a and h pressure tower are in a basic balance, close sequencing valve 6a and 6h.

(8) the 7th equal voltage drop step are called for short seven and all fall E7D

Six all fall after E6D finishes, and open sequencing valve 6a, 6i, and the gas in a tower enters the i tower through pipeline G26 to carry out seven to the i tower and all rise, and after a and i pressure tower are in a basic balance, close sequencing valve 6a and 6i.

(9) reclaim RG

Seven all fall after E7D finishes, and open sequencing valve 9a, KV-15a, and the gas in a tower is forward put into surge tank V1, make the gas pressure in a tower drop to the pressure near surge tank V1, after finishing, close sequencing valve 9a, KV-15a.Also can gas be put into surge tank V1 from the bottom of adsorption tower a.

(10) the contrary BD of putting

(11) vacuumize VC

(12) the 7th equal voltage rise steps are called for short seven and all rise E7R

Vacuumize after VC finishes, open sequencing valve 6a, 6c, the gas in the c tower enters a tower through pipeline G26 to carry out six to a tower and all rises, and after c and a pressure tower are in a basic balance, closes sequencing valve 6c.

(13) the 6th equal voltage rise steps are called for short six and all rise E6R

Seven all rise E7R finish after, open sequencing valve 6d, the gas in the d tower enters a tower through pipeline G26 to carry out six to a tower and all rises, and after d and a pressure tower are in a basic balance, closes sequencing valve 6a, 6d.

(14) the 5th equal voltage rise steps are called for short five and all rise E5R

Six all rise E6R finish after, open sequencing valve 5a, 5e, the gas in the e tower enters a tower through pipeline G25 to carry out five to a tower and all rises, and after e and a pressure tower are in a basic balance, closes sequencing valve 5e.

(15) the 4th equal voltage rise steps are called for short four and all rise E4R

Five all rise E5R finish after, open sequencing valve 5f, the gas in the f tower enters a tower through pipeline G25 to carry out four to a tower and all rises, and after f and a pressure tower are in a basic balance, closes sequencing valve 5a, 5f.

(16) equal for the third time voltage rise step is called for short three and all rises E3R

Four all rise E4R finish after, open sequencing valve 4a, 4g, the gas in the g tower enters a tower through pipeline G24 to carry out three to a tower and all rises, and after g and a pressure tower are in a basic balance, closes sequencing valve 4g.

(17) for the second time equal voltage rise step is called for short two and all rises E2R

Three all rise E3R finish after, open sequencing valve 4h, the gas in the h tower enters a tower through pipeline G24 to carry out two to a tower and all rises, and after h and a pressure tower are in a basic balance, closes sequencing valve 4h, 4a.

(18) for the first time equal voltage rise step is called for short one and all rises E1R

Two all rise E2R finish after, open sequencing valve 3a, 3i, the gas in the i tower enters a tower through pipeline G23 to carry out one to a tower and all rises, and after i and a pressure tower are in a basic balance, closes sequencing valve 3i.

(19) FR that finally boosts

One all rises E1R finish after, open sequencing valve KV-l6, utilize the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and boost from the top to a tower, when a pressure tower rises to adsorptive pressure, close sequencing valve KV-16,3a.

So far, a tower has been finished a circulation, can enter next circulation again.B～i adsorption tower is the same with the circulation step of a tower, just staggers mutually on the time, sees Fig. 8 and Fig. 9.

Embodiments of the invention 4:

Condition such as the conversion gas composition of present embodiment, temperature, adsorbent kind, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span and embodiment 1 are in full accord, and the adsorptive pressure of present embodiment is 2.0MPa (G).

As shown in figure 12, adsorption tower A～K is totally 11 composition first stage pressure swing adsorption apparatus, and the adsorbent that loads from down to up in the adsorption tower is followed successively by activated alumina and Kiselgel A, moves single tower absorption and all presses program 9 times; Adsorption tower a～j is totally 10 composition second stage pressure swing adsorption apparatus, and the adsorbent of filling is a Kiselgel A in the adsorption tower, moves single tower absorption and all presses program seven times, utilizes vacuum pipeline G27 that adsorption tower is vacuumized by vavuum pump P2.P2 is the second stage pressure swing adsorption apparatus vavuum pump.Present embodiment first stage pressure swing adsorption apparatus is purified to carbon dioxide more than 98.5% (V), be used for urea synthesis, the second stage pressure swing adsorption apparatus effect is that working off one's feeling vent one's spleen of first stage pressure swing adsorption apparatus further purified, make in the hydrogen, nitrogen of the second stage pressure swing adsorption apparatus adsorption tower a～j upper end outlet gas concentration lwevel less than 0.2% (V), to satisfy the needs of next step operation of synthetic ammonia.

Conversion gas enters the adsorption tower that first stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower optionally adsorbs the components such as water, organic sulfur, inorganic sulfur and carbon dioxide in the conversion gas successively, components such as the carbon monoxide of Xi Fu partial CO 2 and difficult absorption, methane, nitrogen, hydrogen are not discharged from the port of export and are entered the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower is absorbing carbon dioxide optionally, and components such as the carbon monoxide of difficult absorption, methane, nitrogen, hydrogen are discharged from the port of export and entered compression section.The adsorption tower of first stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, 2E1D ' all falls in two ends one, 2E2D ' all falls in two ends two, 2E3D ' all falls in two ends three, 2E4D ' all falls in two ends four, 2E5D ' all falls in two ends five, 2E6D ' all falls in two ends six, 2E7D ' all falls in two ends seven, 2E8D ' all falls in two ends eight, 2E9D ' all falls in two ends nine, product carbon dioxide step-down D, two ends nine all rise 2E9R ', two ends eight all rise 2E8R ', two ends seven all rise 2E7R ', two ends six all rise 2E6R ', two ends five all rise 2E5R ', two ends four all rise 2E4R ', two ends three all rise 2E3R ', two ends two all rise 2E2R ', two ends one all rise 2E1R ', the FR pressure swing adsorption technique step of finally boosting, first stage pressure swing adsorption apparatus is the product carbon dioxide at the gas that product carbon dioxide step-down D step obtains, the adsorption tower of second stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, one all falls E1D, two all fall E2D, three all fall E3D, four all fall E4D, five all fall E5D, six all fall E6D, seven all fall E7D, the contrary BD of putting, vacuumize VC, seven all rise E7R, six all rise E6R, five all rise E5R, four all rise E4R, three all rise E3R, two all rise E2R, one all rises E1R, the FR pressure swing adsorption technique step of finally boosting, the gaseous mixture that second stage pressure swing adsorption apparatus is in the adsorption tower outlet discharge of adsorption step is mainly nitrogen, hydrogen product wherein also contains a spot of carbon monoxide and methane.Be example with the A tower now, contrast Figure 10 and Figure 12 illustrate the processing step of the present embodiment first stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

At this moment, the A tower has been finished the FR step of finally boosting, open sequencing valve 1A, 2A, conversion gas enters adsorption tower A through pipeline G11, in adsorption tower A, adsorbent optionally adsorbs the water in the conversion gas successively, organic sulfur, component such as inorganic sulfur and carbon dioxide, Xi Fu partial CO 2 and be difficult for the carbon monoxide of absorption not, methane, nitrogen, components such as hydrogen flow out through sequencing valve 2A from the port of export and enter the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, As time goes on, adsorbent water, the total amount of component such as organic sulfur and inorganic sulfur and carbon dioxide constantly increases, when the adsorbents adsorb said components is saturated, stop air inlet, this moment, absorption finished, and closed sequencing valve 1A, 2A, gas concentration lwevel is controlled at 9～10% (V) in working off one's feeling vent one's spleen.

Two ends seven all fall after 2E7D finishes, and open sequencing valve 7A, 7J and 8J, and the gas in the A tower enters the J tower through pipeline G17 and G18 the J tower is carried out eight boost pressures in two ends (being called for short 2E8R '), after A and J pressure tower are in a basic balance, close sequencing valve 7J, 8A and 8J.

(11) product carbon dioxide step-down D

After 2E9D ' end all falls in two ends nine, open sequencing valve KV-15b earlier, product carbon dioxide intermediate buffering jar V2 is put in product carbon dioxide step-down in the A tower, when the pressure of A tower during near V2 pressure, close sequencing valve KV15b, open sequencing valve KV15a again, product carbon dioxide buffer jar V3 is put in the product carbon dioxide step-down in the A tower, when the pressure of A tower during, close sequencing valve KV-15a and 9A near V3 pressure.

(12) the 9th equal voltage rise steps in two ends are called for short two ends nine and all rise 2E9R '

After product carbon dioxide step-down D finishes, open sequencing valve 7A, 7B, 9A and 9B, gas in the B tower enters the A tower through pipeline G19 and G17 the A tower is carried out nine boost pressures in two ends (being called for short 2E9R '), after A and B pressure tower are in a basic balance, closes sequencing valve 7B, 9A and 9B.

(13) the 8th equal voltage rise steps in two ends are called for short two ends eight and all rise 2E8R '

After two ends nine all rise 2E9R ' end, open sequencing valve 7A, 7C, 8A and 8C, gas in the C tower enters the A tower through pipeline G17 and G18 the A tower is carried out eight boost pressures in two ends (being called for short 2E8R '), after A and C pressure tower are in a basic balance, close sequencing valve 7A,, 7C and 8C.

(14) the 7th equal voltage rise steps in two ends are called for short two ends seven and all rise 2E7R '

(15) the 6th equal voltage rise steps in two ends are called for short two ends six and all rise 2E6R '

(16) the 5th equal voltage rise steps in two ends are called for short two ends five and all rise 2E5R '

(17) the 4th equal voltage rise steps in two ends are called for short two ends four and all rise 2E4R '

(18) the equal voltage rise step in two ends for the third time is called for short two ends three and all rises 2E3R '

(19) the equal voltage rise step in the two ends second time is called for short two ends two and all rises 2E2R '

(20) the equal voltage rise step in the two ends first time is called for short two ends one and all rises 2E1R '

(21) FR that finally boosts

Sequencing valve KV-12 is opened after all rising 2E1R ' end in two ends one, utilizes the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and boosts from the top to the A tower, when the A pressure tower rises near adsorptive pressure, closes sequencing valve KV-12,3A.Also can be with unstripped gas to the A tower FR that finally boosts.So far, the A tower has been finished a circulation, can enter next circulation again.B～K adsorption tower is the same with the circulation step of A tower, just staggers mutually on the time, sees Figure 10 and Figure 12.

Be example with a tower now, contrast Figure 11 and Figure 12 illustrate the processing step of the present embodiment second stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

(5) the 4th equal voltage drop step are called for short four and all fall E4D

(6) the 5th equal voltage drop step are called for short five and all fall E5D

(7) the 6th equal voltage drop step are called for short six and all fall E6D

(8) the 7th equal voltage drop step are called for short seven and all fall E7D

(9) the contrary BD of putting

(10) vacuumize VC

(11) the 7th equal voltage rise steps are called for short seven and all rise E7R

(12) the 6th equal voltage rise steps are called for short six and all rise E6R

(13) the 5th equal voltage rise steps are called for short five and all rise E5R

(14) the 4th equal voltage rise steps are called for short four and all rise E4R

(15) equal for the third time voltage rise step is called for short three and all rises E3R

(16) for the second time equal voltage rise step is called for short two and all rises E2R

(17) for the first time equal voltage rise step is called for short one and all rises E1R

(18) FR that finally boosts

So far, a tower has been finished a circulation, can enter next circulation again.B～i adsorption tower is the same with the circulation step of a tower, just staggers mutually on the time, sees Figure 11 and Figure 12.

For present embodiment, adopt particular adsorbent combination of the present invention, under the identical situation of other condition (adsorptive pressure is 2.0MPa (G), conversion gas composition and temperature, sorption cycle time, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span), synthetic ammonia decarburization power consumption per ton on average descends 10%, the investment of decarburization original equipment can save 5%, and the rate of recovery of available gas improves about 3% (V).According to the Ammonia Production arts demand, also can be with more than the hydrogen purification to 99.999% (V) in present embodiment second stage pressure swing adsorption apparatus.In the second stage pressure swing adsorption apparatus processing step of present embodiment, also can cancel and reclaim the RG step, but the rate of recovery of available gas (hydrogen, nitrogen and carbon monoxide) will reduce, and when all pressures number of times of second stage pressure swing adsorption apparatus is more than enough, also can cancel the contrary BD step of putting.At this, do not describe in detail one by one.

Embodiments of the invention 5:

As shown in figure 15, adsorption tower A～K is totally 11 composition first stage pressure swing adsorption apparatus, and the adsorbent that loads from down to up in the adsorption tower is followed successively by activated alumina and Kiselgel A, moves single tower absorption and all presses program 9 times; Adsorption tower a～j is totally 10 composition second stage pressure swing adsorption apparatus, and the adsorbent of filling is a Kiselgel A in the adsorption tower, moves single tower absorption and all presses program seven times, utilizes vacuum pipeline G27 that adsorption tower is vacuumized by vavuum pump P2.P2 is the second stage pressure swing adsorption apparatus vavuum pump.Present embodiment first stage pressure swing adsorption apparatus is purified to carbon dioxide more than 98.5% (V), be used for urea synthesis, the second stage pressure swing adsorption apparatus effect is that working off one's feeling vent one's spleen of first stage pressure swing adsorption apparatus further purified, make in the hydrogen, nitrogen of the second stage pressure swing adsorption apparatus adsorption tower a～j upper end outlet gas concentration lwevel less than 0.2% (V), to satisfy the needs of next step operation of synthetic ammonia.

Conversion gas enters the adsorption tower that first stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower optionally adsorbs the components such as water, organic sulfur, inorganic sulfur and carbon dioxide in the conversion gas successively, components such as the carbon monoxide of Xi Fu partial CO 2 and difficult absorption, methane, nitrogen, hydrogen are not discharged from the port of export and are entered the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower is absorbing carbon dioxide optionally, and components such as the carbon monoxide of difficult absorption, methane, nitrogen, hydrogen are discharged from the port of export and entered compression section.The adsorption tower of first stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, one all falls E1D, two all fall E2D, three all fall E3D, four all fall E4D, five all fall E5D, six all fall E6D, seven all fall E7D, 2E8D ' all falls in two ends eight, 2E9D ' all falls in two ends nine, product carbon dioxide step-down D, two ends nine all rise 2E9R ', two ends eight all rise 2E8R ', seven all rise E7R, six all rise E6R, five all rise E5R, four all rise E4R, three all rise E3R, two all rise E2R, one all rises E1R, the FR pressure swing adsorption technique step of finally boosting, first stage pressure swing adsorption apparatus is the product carbon dioxide at the gas that product carbon dioxide step-down D step obtains, the adsorption tower of second stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, one all falls E1D, two all fall E2D, three all fall E3D, four all fall E4D, five all fall E5D, six all fall E6D, seven all fall E7D, the contrary BD of putting, vacuumize VC, seven all rise E7R, six all rise E6R, five all rise E5R, four all rise E4R, three all rise E3R, two all rise E2R, one all rises E1R, the FR pressure swing adsorption technique step of finally boosting, the gaseous mixture that second stage pressure swing adsorption apparatus is in the adsorption tower outlet discharge of adsorption step is mainly nitrogen, hydrogen product wherein also contains a spot of carbon monoxide and methane.Be example with the A tower now, contrast Figure 13 and Figure 15 illustrate the processing step of the present embodiment first stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

After absorption finishes, open sequencing valve 3A and 3C, the gas in the A tower enters the C tower through pipeline G13 the C tower is carried out a boost pressure (being called for short E1R), after A and C pressure tower are in a basic balance, closes sequencing valve 3A.

One all falls after E1D finishes, and opens sequencing valve 4A and 4D, and the gas in the A tower enters the D tower through pipeline G14 the D tower is carried out secondary boost pressure (being called for short E2R), after A and D pressure tower are in a basic balance, closes sequencing valve 4D.

Two all fall after E2D finishes, and open sequencing valve 4E, and the gas in the A tower enters the E tower through pipeline G14 the E tower is carried out three boost pressures (being called for short E3R), after A and E pressure tower are in a basic balance, close sequencing valve 4A and 4E.

(5) the 4th equal voltage drop step are called for short four and all fall E4D

Three all fall after E3D finishes, and open sequencing valve 5A and 5F, and the gas in the A tower enters the F tower through pipeline G15 the F tower is carried out four boost pressures (being called for short E4R), after A and F pressure tower are in a basic balance, close sequencing valve 5F.

(6) the 5th equal voltage drop step are called for short five and all fall E5D

Four all fall after E4D finishes, and open sequencing valve 5G, and the gas in the A tower enters the G tower through pipeline G15 the G tower is carried out five boost pressures (being called for short E5R), after A and G pressure tower are in a basic balance, close sequencing valve 5A and 5G.

(7) the 6th equal voltage drop step are called for short six and all fall E6D

Five all fall after E5D finishes, and open sequencing valve 6A and 6H, and the gas in the A tower enters the H tower through pipeline G16 the H tower is carried out six boost pressures (being called for short E6R), after A and H pressure tower are in a basic balance, close sequencing valve 6H.

(8) the 7th equal voltage drop step are called for short seven and all fall E7D

Six all fall after E6D finishes, and open sequencing valve 6I, and the gas in the A tower enters the I tower through pipeline G16 the I tower is carried out seven boost pressures (being called for short E7R), after A and I pressure tower are in a basic balance, close sequencing valve 6A and 6I.

Seven all fall after E7D finishes, and open sequencing valve 7A, 7J, 8A and 8J, and the gas in the A tower enters the J tower through pipeline G17 and G18 the J tower is carried out eight boost pressures in two ends (being called for short 2E8R '), after A and J pressure tower are in a basic balance, close sequencing valve 7J and 8J.

After 2E8D ' end all falls in two ends eight, open sequencing valve 7K and 8K, gas in the A tower enters the K tower through pipeline G17 and G18 the K tower is carried out nine boost pressures in two ends (being called for short 2E9R '), after A and K pressure tower are in a basic balance, closes sequencing valve 7A, 7K, 8A and 8K.

(11) product carbon dioxide step-down D

After 2E9D ' end all falls in two ends nine, open sequencing valve 9A and KV-15b earlier, product carbon dioxide intermediate buffering jar V2 is put in product carbon dioxide step-down in the A tower, when the pressure of A tower during near V2 pressure, close sequencing valve KV15b, open sequencing valve KV15a again, product carbon dioxide buffer jar V3 is put in the product carbon dioxide step-down in the A tower, when the pressure of A tower during, close sequencing valve KV-15a and 9A near V3 pressure.

After product carbon dioxide step-down D finishes, open sequencing valve 7A, 7B, 8A and 8B, gas in the B tower enters the A tower through pipeline G18 and G17 the A tower is carried out nine boost pressures in two ends (being called for short 2E9R '), after A and B pressure tower are in a basic balance, closes sequencing valve 7B and 8B.

After two ends nine all rise 2E9R ' end, open sequencing valve 7C and 8C, gas in the C tower enters the A tower through pipeline G17 and G18 the A tower is carried out eight boost pressures in two ends (being called for short 2E8R '), after A and C pressure tower are in a basic balance, close sequencing valve 7A,, 7C, 8A and 8C.

(14) the 7th equal voltage rise steps are called for short seven and all rise E7R

Sequencing valve 6A and 6D are opened after all rising 2E8R ' end in two ends eight, and the gas in the D tower enters the A tower through pipeline G16 the A tower is carried out seven boost pressures (being called for short E7R), after A and D pressure tower are in a basic balance, close sequencing valve 6D.

(15) the 6th equal voltage rise steps are called for short six and all rise E6R

Seven all rise E7R finish after, open sequencing valve 6E, the gas in the E tower enters the A tower through pipeline G16 the A tower is carried out six boost pressures (being called for short E6R), after A and E pressure tower are in a basic balance, closes sequencing valve 6A and 6E.

(16) the 5th equal voltage rise steps are called for short five and all rise E5R

Six all rise E6R finish after, open sequencing valve 5A and 5F, the gas in the F tower enters the A tower through pipeline G15 the A tower is carried out five boost pressures (being called for short E5R), after A and F pressure tower are in a basic balance, closes sequencing valve 5F.

(17) the 4th equal voltage rise steps are called for short four and all rise E4R

Five all rise E5R finish after, open sequencing valve 5G, the gas in the G tower enters the A tower through pipeline G15 the A tower is carried out four boost pressures (being called for short E4R), after A and G pressure tower are in a basic balance, closes sequencing valve 5A and 5G.

(18) equal for the third time voltage rise step is called for short three and all rises E3R

Four all rise E4R finish after, open sequencing valve 4A and 4H, the gas in the H tower enters the A tower through pipeline G14 the A tower is carried out three boost pressures (being called for short E3R), after A and H pressure tower are in a basic balance, closes sequencing valve 4H.

(19) for the second time equal voltage rise step is called for short two and all rises E2R

Three all rise E3R finish after, open sequencing valve 4I, the gas in the I tower enters the A tower through pipeline G14 the A tower is carried out secondary boost pressure (being called for short E2R), after A and I pressure tower are in a basic balance, closes sequencing valve 4A and 4I.

(20) for the first time equal voltage rise step is called for short one and all rises E1R

Two all rise E2R finish after, open sequencing valve 3A and 3J, the gas in the J tower enters the A tower through pipeline G13 the A tower is carried out boost pressure in two ends (being called for short E1R), after A and J pressure tower are in a basic balance, closes sequencing valve 3J.

(21) FR that finally boosts

One all rises E1R finish after, open sequencing valve KV-12, utilize the adsorption tower that is in adsorption step to work off one's feeling vent one's spleen and boost from the top to the A tower, when the A pressure tower rises near adsorptive pressure, close sequencing valve KV-12,3A.Also can be with unstripped gas to the A tower FR that finally boosts.So far, the A tower has been finished a circulation, can enter next circulation again.B～K adsorption tower is the same with the circulation step of A tower, just staggers mutually on the time, sees Figure 13 and Figure 15.

Be example with a tower now, contrast Figure 14 and Figure 15 illustrate the processing step of the present embodiment second stage pressure swing adsorption apparatus adsorption tower in a cyclic process:

(1) absorption A

(5) the 4th equal voltage drop step are called for short four and all fall E4D

(6) the 5th equal voltage drop step are called for short five and all fall E5D

Four all fall after E4D finishes, and open sequencing valve 5a, and the gas in the 5g, a tower enters the g tower through pipeline G25 to carry out five to the g tower and all rise, and after a and f pressure tower are in a basic balance, close sequencing valve 5f.

(7) the 6th equal voltage drop step are called for short six and all fall E6D

(8) the 7th equal voltage drop step are called for short seven and all fall E7D

(9) the contrary BD of putting

(10) vacuumize VC

(12) the 6th equal voltage rise steps are called for short six and all rise E6R

(18) FR that finally boosts

So far, a tower has been finished a circulation, can enter next circulation again.B～i adsorption tower is the same with the circulation step of a tower, just staggers mutually on the time, sees Figure 14 and Figure 15.

Embodiments of the invention 6:

Condition such as the conversion gas composition of present embodiment, temperature, adsorbent kind, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span and embodiment 1 are in full accord, and the adsorptive pressure of present embodiment is 0.8MPa (G).

Adsorption tower A～I is totally 9 composition first stage pressure swing adsorption apparatus, and the adsorbent that loads from down to up in the adsorption tower is followed successively by activated alumina and Kiselgel A, moves single tower absorption and all presses program 7 times; Adsorption tower a～g is totally 7 composition second stage pressure swing adsorption apparatus, and the adsorbent of filling is a Kiselgel A in the adsorption tower, moves single tower absorption and all presses program four times, utilizes vacuum pipeline G27 that adsorption tower is vacuumized by vavuum pump P2.P2 is the second stage pressure swing adsorption apparatus vavuum pump.Present embodiment first stage pressure swing adsorption apparatus is purified to carbon dioxide more than 98.5% (V), be used for urea synthesis, the second stage pressure swing adsorption apparatus effect is that working off one's feeling vent one's spleen of first stage pressure swing adsorption apparatus further purified, make in the hydrogen, nitrogen of the second stage pressure swing adsorption apparatus adsorption tower a～g upper end outlet gas concentration lwevel less than 0.2% (V), to satisfy the needs of next step operation of synthetic ammonia.

Conversion gas enters the adsorption tower that first stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower optionally adsorbs the components such as water, organic sulfur, inorganic sulfur and carbon dioxide in the conversion gas successively, components such as the carbon monoxide of Xi Fu partial CO 2 and difficult absorption, methane, nitrogen, hydrogen are not discharged from the port of export and are entered the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower is absorbing carbon dioxide optionally, and components such as the carbon monoxide of difficult absorption, methane, nitrogen, hydrogen are discharged from the port of export and entered compression section.The adsorption tower of first stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, 2E1D ' all falls in two ends one, 2E2D ' all falls in two ends two, 2E3D ' all falls in two ends three, 2E4D ' all falls in two ends four, 2E5D ' all falls in two ends five, 2E6D ' all falls in two ends six, 2E7D ' all falls in two ends seven, vacuumize VC, two ends seven all rise 2E7R ', two ends six all rise 2E6R ', two ends five all rise 2E5R ', two ends four all rise 2E4R ', two ends three all rise 2E3R ', two ends two all rise 2E2R ', two ends one all rise 2E1R ', the FR pressure swing adsorption technique step of finally boosting, first stage pressure swing adsorption apparatus is the product carbon dioxide at the gas that product carbon dioxide step-down D step obtains, the adsorption tower of second stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, one all falls E1D, two all fall E2D, three all fall E3D, four all fall E4D, the contrary BD of putting, vacuumize VC, four all rise E4R, three all rise E3R, two all rise E2R, one all rises E1R, the FR pressure swing adsorption technique step of finally boosting, the gaseous mixture that second stage pressure swing adsorption apparatus is in the adsorption tower outlet discharge of adsorption step is mainly nitrogen, hydrogen product wherein also contains a spot of carbon monoxide and methane.

For present embodiment, adopt particular adsorbent combination of the present invention, under the identical situation of other condition (adsorptive pressure is 0.8MPa (G), conversion gas composition and temperature, sorption cycle time, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span), synthetic ammonia decarburization power consumption per ton on average descends 10%, the investment of decarburization original equipment can save 5%, and the rate of recovery of available gas improves about 0.5% (V).According to the Ammonia Production arts demand, also can be with more than the hydrogen purification to 99.999% (V) in present embodiment second stage pressure swing adsorption apparatus.In the second stage pressure swing adsorption apparatus processing step of present embodiment, also can cancel and reclaim the RG step, but the rate of recovery of available gas (hydrogen, nitrogen and carbon monoxide) will reduce, and when all pressures number of times of second stage pressure swing adsorption apparatus is more than enough, also can cancel the contrary BD step of putting.At this, do not describe in detail one by one.

Embodiments of the invention 7:

Conversion gas enters the adsorption tower that first stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower optionally adsorbs the components such as water, organic sulfur, inorganic sulfur and carbon dioxide in the conversion gas successively, components such as the carbon monoxide of Xi Fu partial CO 2 and difficult absorption, methane, nitrogen, hydrogen are not discharged from the port of export and are entered the adsorption tower that second stage pressure swing adsorption apparatus is in adsorption step, adsorbent in the adsorption tower is absorbing carbon dioxide optionally, and components such as the carbon monoxide of difficult absorption, methane, nitrogen, hydrogen are discharged from the port of export and entered compression section.The adsorption tower of first stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, 2E1D ' all falls in two ends one, 2E2D ' all falls in two ends two, 2E3D ' all falls in two ends three, 2E4D ' all falls in two ends four, 2E5D ' all falls in two ends five, 2E6D ' all falls in two ends six, 2E7D ' all falls in two ends seven, vacuumize VC, two sections rise 2ER, two ends seven all rise 2E7R ', two ends six all rise 2E6R ', two ends five all rise 2E5R ', two ends four all rise 2E4R ', two ends three all rise 2E3R ', two ends two all rise 2E2R ', two ends one all rise 2E1R ', the FR pressure swing adsorption technique step of finally boosting, first stage pressure swing adsorption apparatus is the product carbon dioxide at the gas that product carbon dioxide step-down D step obtains, the adsorption tower of second stage pressure swing adsorption apparatus experiences absorption A successively in a cycle period, one all falls E1D, two all fall E2D, three all fall E3D, four all fall E4D, reclaim RC, vacuumize VC, four all rise E4R, three all rise E3R, two all rise E2R, one all rises E1R, the FR pressure swing adsorption technique step of finally boosting, the gaseous mixture that second stage pressure swing adsorption apparatus is in the adsorption tower outlet discharge of adsorption step is mainly nitrogen, hydrogen product wherein also contains a spot of carbon monoxide and methane.

For present embodiment, adopt particular adsorbent combination of the present invention, under the identical situation of other condition (adsorptive pressure is 0.8MPa (G), conversion gas composition and temperature, sorption cycle time, power-equipment performance, instrument and meter and control function, special-purpose sequencing valve and hydraulic system structure and life-span), synthetic ammonia decarburization power consumption per ton on average descends 10%, the investment of decarburization original equipment can save 5%, and the rate of recovery of available gas improves about 0.5% (V).According to the Ammonia Production arts demand, also can be with more than the hydrogen purification to 99.999% (V) in present embodiment second stage pressure swing adsorption apparatus.In the second stage pressure swing adsorption apparatus processing step of present embodiment, when all pressures number of times of second stage pressure swing adsorption apparatus is more than enough, also can cancel the contrary BD step of putting.At this, do not describe in detail one by one.

Claims

1, a kind of improved two sections pressure swing adsorption decarbonization methods, it is characterized in that the method adopts the two-stage pressure swing adsorption apparatus serial operation, synthetic-ammonia transformation gas at first enters first section pressure swing adsorption gas separation device, carbon dioxide in the conversion gas partly is removed and carries the dense product carbon dioxide that is, the middle gaseous mixture that obtains from first section pressure swing adsorption gas separation device adsorption tower outlet enters second section pressure swing adsorption gas separation device, impurity absorption in the middle gaseous mixture is got off, the gas that is not adsorbed enters next workshop section as product gas, first section pressure swing adsorption gas separation device adsorption tower experiences absorption A successively in a cycle period, two ends drop pressure 2ED ', product carbon dioxide step-down D, two ends boost pressure 2ER ', the FR processing step that finally boosts, second section pressure swing adsorption gas separation device adsorption tower experience absorption A successively in a cycle period, drop pressure ED, the contrary BD of putting, vacuumize VC, boost pressure ER, the FR processing step finally boosts.

2, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 1 is characterized in that increasing forward drop pressure ED after first section pressure swing adsorption gas separation device adsorption tower process cycles step absorption A.

3, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 1 is characterized in that increasing purging CP step after first section pressure swing adsorption gas separation device adsorption tower process cycles step product carbon dioxide step-down D.

4, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 1 is characterized in that first section pressure swing adsorption gas separation device adsorption tower process cycles step product carbon dioxide step-down D increase afterwards vacuumizes the VC step.

5,, it is characterized in that first section pressure swing adsorption gas separation device adsorption tower process cycles step two ends drop pressure 2ED ' increases gaseous mixture step-down D1 step afterwards according to the described a kind of improved two sections pressure swing adsorption decarbonization methods of arbitrary claim in the claim 1 to 4.

6, according to the described a kind of improved two sections pressure swing adsorption decarbonization methods of arbitrary claim in the claim 1 to 4, it is characterized in that first section pressure swing adsorption gas separation device adsorption tower process cycles step two ends drop pressure 2ED ' increases displacement P step afterwards, working off one's feeling vent one's spleen of adsorption tower of displacement enters other system or emptying.

7, according to the described a kind of improved two sections pressure swing adsorption decarbonization methods of arbitrary claim in the claim 1 to 4, when it is characterized in that first section pressure swing adsorption gas separation device adsorption tower replaced the P step, another adsorption tower of working off one's feeling vent one's spleen to first section pressure swing adsorption gas separation device of displacement adsorption tower boosts, and carries out the displacement gas PR that boosts simultaneously before the boost pressure 2ER ' of two ends.

8, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 6, it is characterized in that increasing displacement P step after first section pressure swing adsorption gas separation device adsorption tower process cycles step gaseous mixture step-down D1, working off one's feeling vent one's spleen of adsorption tower of displacement enters other system or emptying.

9, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 4, it is characterized in that increasing recovery RG step after second section pressure swing adsorption gas separation device adsorption tower process cycles step drop pressure ED, increase simultaneously two sections gas lifts and press the 2ER step after first section pressure swing adsorption gas separation device adsorption tower process cycles step vacuumizes the VC step, above-mentioned second section pressure swing adsorption gas separation device adsorption tower reclaims between RG step and two sections gas lifts pressures of the first section pressure swing adsorption gas separation device adsorption tower 2ER step and is connected by surge tank V1.

10, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 4, it is characterized in that increasing recovery RG step after second section pressure swing adsorption gas separation device adsorption tower process cycles step drop pressure ED, after first section pressure swing adsorption gas separation device adsorption tower process cycles step vacuumizes the VC step, increase simultaneously two sections gas lifts and press the 2ER step, and two ends drop pressure 2ED ' increases gaseous mixture step-down D1 step afterwards; Above-mentioned second section pressure swing adsorption gas separation device adsorption tower reclaims between RG step and two sections gas lifts pressures of the first section pressure swing adsorption gas separation device adsorption tower 2ER step and is connected by surge tank V1.

11, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 4, it is characterized in that increasing recovery RG step after second section pressure swing adsorption gas separation device adsorption tower process cycles step drop pressure ED, increase simultaneously two sections gas lifts and press 2ER step and two ends drop pressure after first section pressure swing adsorption gas separation device adsorption tower process cycles step vacuumizes the VC step, above-mentioned second section pressure swing adsorption gas separation device adsorption tower reclaims between RG step and two sections gas lifts pressures of the first section pressure swing adsorption gas separation device adsorption tower 2ER step and is connected by surge tank V1.

12, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 4, it is characterized in that increasing recovery RG step after second section pressure swing adsorption gas separation device adsorption tower process cycles step drop pressure ED, after first section pressure swing adsorption gas separation device adsorption tower process cycles step vacuumizes the VC step, increase simultaneously two sections gas lifts and press the 2ER step, and two ends drop pressure 2ED ' increases displacement P step afterwards, another adsorption tower of working off one's feeling vent one's spleen to first section pressure swing adsorption gas separation device of displacement adsorption tower boosts, and carries out the displacement gas PR that boosts simultaneously before the boost pressure 2ER ' of two ends; Above-mentioned second section pressure swing adsorption gas separation device adsorption tower reclaims between RG step and two sections gas lifts pressures of the first section pressure swing adsorption gas separation device adsorption tower 2ER step and is connected by surge tank V1.

13, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 4, it is characterized in that increasing recovery RG step after second section pressure swing adsorption gas separation device adsorption tower process cycles step drop pressure ED, after first section pressure swing adsorption gas separation device adsorption tower process cycles step vacuumizes the VC step, increase by two sections gas lifts simultaneously and press the 2ER steps; And two ends drop pressure 2ED ' increases gaseous mixture step-down D1 step and displacement P step afterwards in turn, and working off one's feeling vent one's spleen of adsorption tower of displacement enters other system or emptying; Above-mentioned second section pressure swing adsorption gas separation device adsorption tower reclaims between RG step and two sections gas lifts pressures of the first section pressure swing adsorption gas separation device adsorption tower 2ER step and is connected by surge tank V1.

14, according to the described a kind of improved two sections pressure swing adsorption decarbonization methods of arbitrary claim in the claim 1 to 4, it is characterized in that in first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment.

15, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 5, it is characterized in that in first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment.

16, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 9, it is characterized in that in first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment.

17, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 6, it is characterized in that in first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide replacement gas intermediate buffering jar V4, put into product carbon dioxide intermediate buffering jar V2 again, put into product carbon dioxide buffer jar V3 at last, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment, and the gas of product carbon dioxide replacement gas intermediate buffering jar V4 is put into product carbon dioxide replacement gas surge tank V5 by pressure or Flow-rate adjustment.

18, according to the described a kind of improved two sections pressure swing adsorption decarbonization methods of arbitrary claim in the claim 1 to 4, it is characterized in that in first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, put into product carbon dioxide gas holder V at last, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment.

19, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 6, it is characterized in that in first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide replacement gas intermediate buffering jar V4, next puts into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, put into product carbon dioxide gas holder V at last, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment, and the gas of product carbon dioxide replacement gas intermediate buffering jar V4 is put into product carbon dioxide replacement gas surge tank V5 by pressure or Flow-rate adjustment.

20, according to the described a kind of improved two sections pressure swing adsorption decarbonization methods of arbitrary claim in the claim 1 to 4, it is characterized in that the adsorbent that loads from down to up in the first stage pressure swing adsorption apparatus adsorption tower is activated alumina and Kiselgel A, or activated alumina, active carbon and Kiselgel A, the adsorbent of filling is a Kiselgel A in the second stage pressure swing adsorption apparatus adsorption tower, or molecular sieve.

21, according to the described a kind of improved two sections pressure swing adsorption decarbonization methods of arbitrary claim in the claim 1 to 4, it is characterized in that the first stage pressure swing adsorption apparatus adsorption step work off one's feeling vent one's spleen in the mean concentration of carbon dioxide be 7～15% (V).

22, a kind of improved two sections pressure swing adsorption decarbonization methods, it is characterized in that the method adopts the two-stage pressure swing adsorption apparatus serial operation, synthetic-ammonia transformation gas at first enters first section pressure swing adsorption gas separation device, carbon dioxide in the conversion gas partly is removed and carries the dense product carbon dioxide that is, the middle gaseous mixture that obtains from first section pressure swing adsorption gas separation device adsorption tower outlet enters second section pressure swing adsorption gas separation device, impurity absorption in the middle gaseous mixture is got off, the gas that is not adsorbed enters next workshop section as product gas, first section pressure swing adsorption gas separation device adsorption tower experiences absorption A successively in a cycle period, two ends drop pressure 2ED ', vacuumize VC, two ends boost pressure 2ER ', the FR processing step that finally boosts, second section pressure swing adsorption gas separation device adsorption tower experience absorption A successively in a cycle period, drop pressure ED, the contrary BD of putting, vacuumize VC, boost pressure ER, the FR processing step finally boosts.

23, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 22 is characterized in that first section pressure swing adsorption gas separation device adsorption tower process cycles step two ends drop pressure 2ED ' increases gaseous mixture step-down D1 step afterwards.

24, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 22, it is characterized in that first section pressure swing adsorption gas separation device adsorption tower process cycles step two ends drop pressure 2ED ' increases displacement P step afterwards, working off one's feeling vent one's spleen of adsorption tower of displacement enters other system or emptying.

25, a kind of improved two sections pressure swing adsorption decarbonization methods, it is characterized in that the method adopts the two-stage pressure swing adsorption apparatus serial operation, synthetic-ammonia transformation gas at first enters first section pressure swing adsorption gas separation device, carbon dioxide in the conversion gas partly is removed and carries the dense product carbon dioxide that is, the middle gaseous mixture that obtains from first section pressure swing adsorption gas separation device adsorption tower outlet enters second section pressure swing adsorption gas separation device, impurity absorption in the middle gaseous mixture is got off, the gas that is not adsorbed enters next workshop section as product gas, first section pressure swing adsorption gas separation device adsorption tower experiences absorption A successively in a cycle period, two ends drop pressure 2ED ', product carbon dioxide step-down D, two ends boost pressure 2ER ', the FR processing step that finally boosts, second section pressure swing adsorption gas separation device adsorption tower experience absorption A successively in a cycle period, drop pressure ED, reclaim RG, vacuumize VC, boost pressure ER, the FR processing step finally boosts.

26, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 25 is characterized in that first section pressure swing adsorption gas separation device adsorption tower process cycles step two ends drop pressure 2ED ' increases gaseous mixture step-down D1 step afterwards.

27, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 25, it is characterized in that first section pressure swing adsorption gas separation device adsorption tower process cycles step two ends drop pressure 2ED ' increases displacement P step afterwards, working off one's feeling vent one's spleen of adsorption tower of displacement enters other system or emptying.

28, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 27, when it is characterized in that first section pressure swing adsorption gas separation device adsorption tower replaced the P step, another adsorption tower of working off one's feeling vent one's spleen to first section pressure swing adsorption gas separation device of displacement adsorption tower boosts, and carries out the displacement gas PR that boosts simultaneously before the boost pressure 2ER ' of two ends.

29, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 25, it is characterized in that increasing displacement P step after first section pressure swing adsorption gas separation device adsorption tower process cycles step gaseous mixture step-down D1, working off one's feeling vent one's spleen of adsorption tower of displacement enters other system or emptying.

30, a kind of improved two sections pressure swing adsorption decarbonization methods according to claim 25, it is characterized in that in first section pressure swing adsorption gas separation device adsorption tower process cycles step, when product carbon dioxide step-down D step is carried out, the product carbon dioxide is at first put into product carbon dioxide intermediate buffering jar V2, put into product carbon dioxide buffer jar V3 again, the gas of product carbon dioxide intermediate buffering jar V2 is put into product carbon dioxide buffer jar V3 by pressure or Flow-rate adjustment.