JP4663103B2 - Syngas production - Google Patents

Description

【００４４】
（３）製造例 ２〜４
製造例１において、スチームと二酸化炭素の供給量を変化させて、（二酸化炭素＋スチーム）／カーボン比を変化させ、その他の条件は同一にして反応を行った。その結果を表１に示す。
【００４５】
表１の結果から、スチーム／カーボン比が１．０８、二酸化炭素／カーボン比が０．４２、すなわち（二酸化炭素＋スチーム）／カーボン比が１．５において、熱量原単位、熱回収系設備容量が最小になり、最も経済的な合成ガスの製造が可能であることが判明した。また、炭素質の析出が、（二酸化炭素＋スチーム）／カーボン比３以下でも生じないことも明らかである。
【００４６】
【発明の効果】
以上説明したように、本発明の合成ガスの製法によれば、ＣｏＯ、ＮｉＯの少なくとも１種をＭｇＯまたはＭｇＯ／ＣａＯと複合酸化物化し、Ｃｏ、Ｎｉの少なくとも１種を高分散化した改質用触媒を用いて、炭化水素と二酸化炭素およびスチームとからリホームング反応により合成ガスを得るようにしているので、運転コスト、設備コストが最も安くなる反応条件においても、炭素質の析出がなく、長期間安定して製造を行うことができる。
【００４７】
また、前段に予備転換工程を設けてナフサなどの重質炭化水素をメタンなどの軽質炭化水素に転換してこれとスチームとを反応させれば、重質炭化水素も問題なく原料とすることができる。
さらに、反応器からの合成ガス含有ガスの熱を回収してスチームの熱源とすれば、運転コストを低減できる。
また、反応器への二酸化炭素とスチームの供給比を調節して、反応器から導出された合成ガス含有ガスの組成を、合成ガスを使用する後段のプロセスの種類に応じて調節すると、後段のプロセスも含めたプロセス全体の製造コストを低減できる。
【図面の簡単な説明】
【図１】従来の改質用触媒を用いた場合の反応圧力と（二酸化炭素＋スチーム）／カーボン比との関係を示す図表である。
【図２】本発明で用いられる触媒の表面状態を模式的に示す説明図である。
【図３】本発明の合成ガスの製法の一例に用いられる装置の概略構成図である。
【図４】本発明の合成ガスの製法の他の例に用いられる装置の概略構成図である。
【符号の説明】
７…反応器、１２…第１熱交換器、２１…スチームドラム、２５…プレコンバータ[0001]
[Technical field to which the invention belongs]
The present invention relates to a method for producing synthesis gas by reacting hydrocarbons such as methane, natural gas, and naphtha with carbon dioxide and steam (steam), so that synthesis gas can be produced stably at low cost. It is a thing.
[0002]
[Prior art]
Conventionally, hydrocarbons such as methane, natural gas, naphtha, petroleum gas, heavy oil, and crude oil, carbon dioxide, and steam are sent to a reactor and reacted at a temperature of 800 to 1000 ° C. in the presence of a reforming catalyst (recycled). A method for producing a synthesis gas is known.
As the reforming catalyst, a nickel / alumina catalyst, a nickel / magnesia / alumina catalyst, or the like is used.
[0003]
The synthesis gas produced in this way is used for applications such as DME (dimethyl ether) synthesis, FT (Fischer-Tropsch) synthesis, methanol synthesis, and the like. / Cm ² (In this specification, all pressures are expressed in gauge pressure kg / cm ² G.
However, there is a situation in which a high-pressure synthesis gas is desired by users (purchasers) of synthesis gas.
[0004]
By the way, in the production of synthesis gas by this reforming reaction, it is said that there are optimum reaction conditions from the viewpoint of energy efficiency at the time of reaction and apparatus cost.
In a typical reforming reaction, temperature is 600 to 1000 ° C., the pressure is in the range of 5~30kg / cm ^2, typical reaction temperature of 900 ° C., the pressure is performed under a condition of 20 kg / cm ² Yes.
[0005]
On the other hand, in a synthesis gas production plant by a reforming reaction, there is a (carbon dioxide + steam) / carbon ratio as a factor that greatly affects its operation cost and equipment cost.
This (carbon dioxide + steam) / carbon ratio is the ratio of the total number of moles of carbon dioxide and steam (water) to 1 mole of carbon in the raw material hydrocarbon. This (carbon dioxide + steam) / carbon ratio is preferably about 1 in terms of chemical equivalent.
[0006]
Therefore, it is most preferable to perform a reforming reaction under reaction conditions of a temperature of 900 ° C., a pressure of 20 kg / cm ² , and a (carbon dioxide + steam) / carbon ratio of about 1.
However, if the reaction is carried out under the optimum conditions of a temperature of 900 ° C., a pressure of 20 kg / cm ² , and a (carbon dioxide + steam) / carbon ratio of around 1, a large amount of carbon is deposited in the conventional reforming catalyst. It was impossible to get the reaction done.
[0007]
FIG. 1 shows the relationship between the reaction pressure at a reaction temperature of 900 ° C. and the (carbon dioxide + steam) / carbon ratio when a conventional reforming catalyst is used, and the hatched area in the graph. Indicates that the carbonaceous deposition is less than the allowable value and is in a practical range, and other regions indicate that the carbonaceous deposition exceeds the allowable value and is not practical.
From this graph, it can be seen that a conventional reforming catalyst is used, and the reaction cannot be carried out practically under the conditions of a temperature of 900 ° C., a pressure of 20 kg / cm ² and a (carbon dioxide + steam) / carbon ratio of about 1.
[0008]
For this reason, the conventional method for producing synthesis gas by reforming reaction is operated with a (carbon dioxide + steam) / carbon ratio of 3 or more, which requires excessive carbon dioxide and steam, increases production costs, and The equipment cost was also high.
[0009]
[Problems to be solved by the invention]
Therefore, the problem in the present invention is that when producing synthesis gas under the optimum conditions of a temperature of 900 ° C., a pressure of 20 kg / cm ² , and a (carbon dioxide + steam) / carbon ratio of 1 by reforming reaction, And to enable stable and low-cost production over a long period of time.
[0010]
[Means for Solving the Problems]
Such a problem can be solved by using the following reforming catalyst. Further, by using this catalyst, carbon can be used even in a wide range of conditions where the pressure is 5 to 40 kg / cm ² , the temperature is 750 to 950 ° C., and the (carbon dioxide + steam) / carbon ratio is 1.3 to 2.5. There is no precipitation of quality, and it is possible to produce an economical synthesis gas. This reforming catalyst is made of a composite oxide having a composition represented by the following formula, and at least one of Co and Ni is highly dispersed in the composite oxide.
b Co · cNi · dMg · eCa · fO
( Wherein b , c, d and e are mole fractions , b + c + d + e = 1 , 0.001 ≦ (b + c) ≦ 0.3, 0 ≦ b ≦ 0.3, 0 ≦ c ≦ 0.3) 0.6 ≦ (d + e) ≦ 0.999, 0 <d ≦ 0.999, 0 ≦ e ≦ 0.999, and f = the number necessary for the element to maintain a charge balance with oxygen .
[0011]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described in detail below. First, the reforming catalyst used in the synthesis gas production method of the present invention will be described. The reforming catalyst is made of a complex oxide having a composition represented by the following formula, is at least in one of C o and Ni are highly dispersed in the composite oxide.
b Co · cNi · dMg · eCa · fO
( Wherein b , c, d and e are mole fractions , b + c + d + e = 1 , 0.001 ≦ (b + c) ≦ 0.3, 0 ≦ b ≦ 0.3, 0 ≦ c ≦ 0.3) 0.6 ≦ (d + e) ≦ 0.999, 0 <d ≦ 0.999, 0 ≦ e ≦ 0.999, and f = the number necessary for the element to maintain a charge balance with oxygen .
[0012]
The periodic table here is based on IUPAC .
[0013]
The cobalt content (b) is 0 ≦ b ≦ 0.3, preferably 0 ≦ b ≦ 0.25, and more preferably 0 ≦ b ≦ 0.20. If the cobalt content (b) exceeds 0.3, high dispersion described later is hindered, and a carbonaceous precipitation preventing effect cannot be sufficiently obtained.
[0014]
The nickel content (c) is 0 ≦ c ≦ 0.3, preferably 0 ≦ c ≦ 0.25, and more preferably 0 ≦ c ≦ 0.20. If the nickel content (c) exceeds 0.3, high dispersion described later is hindered, and a carbonaceous precipitation preventing effect cannot be sufficiently obtained.
[0015]
The total amount (b + c) of the cobalt content (b) and the nickel content (c) is 0.001 ≦ b + c ≦ 0.3, preferably 0.001 ≦ b + c ≦ 0.25, Preferably it is 0.0001 <= b + c <= 0.20. When the total content (b + c) exceeds 0.3, high dispersion described later is inhibited, and a carbonaceous precipitation preventing effect cannot be sufficiently obtained. If it is less than 0.001, the reaction activity is low.
[0016]
The total amount (d + e) of the magnesium content (d) and the calcium content (e) is 0.6 ≦ (d + e) ≦ 0.9998, preferably 0.70 ≦ (d + e) ≦ 0.9998, More preferably, 0.77 ≦ (d + e) ≦ 0.9998. Among these, the magnesium content (d) is 0 <d ≦ 0.999, preferably 0.20 ≦ d ≦ 0.9998, more preferably 0.37 ≦ d ≦ 0.9998, and the calcium content (E) is 0 ≦ e <0.999, preferably 0 ≦ e ≦ 0.5, more preferably 0 ≦ e ≦ 0.3, and may lack calcium.
[0017]
The total amount of the magnesium content (d) and the calcium content and (e) (d + e) is determined by the balance between the cobalt content (b) and the nickel content (c). (D + e) exhibits an excellent effect on the reforming reaction at any ratio within the above range, but magnesium (d) is effective in suppressing carbonaceous precipitation when the content of calcium (e) is large. The catalytic activity is low compared with the case where there are many. Therefore, if you focus on activity, since the calcium content (e) is lowered Eru Yue and activity 0.5 undesirable.
[0018]
The composite oxide in the present invention is a kind of solid solution in which MgO and CaO have a rock salt type crystal structure, and a part of Mg or Ca atoms located in the lattice is substituted with Co and Ni, and form a single phase. It is not intended to refer to a single oxide mixture of each element. In the present invention, Co, at least one N i is a highly dispersed state in this composite oxide.
[0019]
The dispersion in the present invention is generally defined in the catalyst field, and is supported as described in, for example, “Catalyst Course Vol. 5 Catalyst Design”, page 141 (Catalyst Society edition, published by Kodansha). It is determined as the ratio of the number of atoms exposed on the catalyst surface to the total number of atoms of the metal.
[0020]
The present invention will be specifically described with reference to the schematic diagram of FIG. 2. The surface of the catalyst 101 made of a composite oxide has innumerable fine particles 102, 102... The microparticles 102 are made of a Co metal element or a compound thereof after activation (reduction) treatment described later. When the Co forming the microparticles 102, the number of atoms of metal element or a compound thereof N i is A, the number of atoms exposed on the surface of the particles 102 of these atoms and B, B / A is distributed Degree.
[0021]
Assuming that the atoms exposed to the surface of the microparticles 102 are involved in the catalytic reaction, those having a dispersity close to 1 have many atoms distributed on the surface, and the active center is It is thought that it can increase and become highly active.
If the particle size of the microparticles 102 becomes extremely small, most of the atoms forming the microparticles 102 are exposed on the surface of the particles 102, and the degree of dispersion approaches 1. Therefore, the particle size of the microparticles 102 can also serve as an index representing the degree of dispersion.
[0022]
In the catalyst used in the present invention, the diameter of the fine particles 102 is less than 3.5 nm, which is a measurement limit of various measurement methods, for example, X-ray diffraction method, and thus the degree of dispersion is high and the dispersion state is high. Can be said. Therefore, cobalt participating in the reaction, increases the number of atoms of nickel, become highly active, the reaction proceeds stoichiometrically, thereby preventing deposition of carbonaceous (carbon).
[0023]
As a method for producing such a reforming catalyst, any method may be used as long as it is a preparation method capable of obtaining the above-described highly dispersed state of cobalt and nickel. Method, coprecipitation method, sol-gel method (hydrolysis method), uniform precipitation method and the like, and Japanese Patent Application No. 6-301645 (see Japanese Patent Application Laid-Open No. 8-131835) previously filed by the present applicant. The disclosed preparation methods can also be used.
[0024]
For example, to prepare the coprecipitation method, first cobalt, nickel, magnesium, and organic salts such as acetate salts of calcium, a complete solution in which a water-soluble salt dissolved in water, such as inorganic salts such as nitrates. While this aqueous solution is being stirred, a precipitation agent is formed by adding a precipitation agent at 20 to 120 ° C., preferably at 40 to 100 ° C. In order to disperse the catalyst component highly, it is preferable to stir the precipitate when it is generated, and it is preferable to complete the generation of the precipitate by stirring for 10 minutes or more after the precipitate is generated.
[0025]
Preferred precipitation agents are sodium and / or potassium carbonates, bicarbonates, oxalates and hydroxides. Ammonium carbonate, ammonium hydroxide, ammonia (ammonia water) and the like can also be used as a precipitating agent.
The addition of a precipitating agent raises the pH, and the compound comprising the above components precipitates in the form of a thermally decomposable hydroxide. The final pH of the mixture is preferably 6 or more, more preferably in the range of 8-11. When a precipitate is obtained, the precipitate is filtered, washed repeatedly with water or an aqueous ammonium carbonate solution, and then dried at a temperature of 100 ° C. or higher. Next, the dried precipitate is calcined in the air at 500 to 1500 ° C., preferably 1000 to 1300 ° C. for 20 hours to thermally decompose the thermally decomposable hydroxide to obtain the target reforming catalyst.
Alternatively, the precipitate may be primarily sintered at 400 to 600 ° C., molded, and then subjected to secondary firing at 1000 to 1300 ° C. to obtain a reforming catalyst.
[0026]
The catalyst thus obtained has a specific surface area of 0.2 to ⁵ m ² / g.
Further, the obtained catalyst can be pulverized and used as a powder, but if necessary, it can be molded by a compression molding machine and used as a tablet. These catalysts can also be used in combination with quartz sand, alumina, magnesia, calcia, and other diluents.
[0027]
Next, the synthesis gas production method of the present invention will be described in detail. First, the reforming catalyst is activated in advance. In this activation treatment, the catalyst is heated in the presence of a reducing gas such as hydrogen gas at 500 to 1000 ° C., preferably 600 to 1000 ° C., more preferably 650 to 1000 ° C. for about 0.5 to 30 hours. Is done by doing. The reducing gas may be diluted with an inert gas such as nitrogen gas. This activation treatment can also be performed in a reactor that performs a reforming reaction. This activation treatment, fine particles of the catalyst 101 surface in Figure 2 102, 102 ... is reduced Co, at least one N i is a metal element or a compound thereof, the catalytic activity is expressed. The activation treatment here is performed at a higher temperature than the activation of the conventional Co oxide catalyst. All conventional Co oxide catalysts are carried out at less than 500 ° C., and such high temperature activation treatment may contribute to the above high dispersion.
[0028]
FIG. 3 shows a production apparatus for carrying out an example of the production method of the present invention. In this example, the description will be given using natural gas mainly composed of methane as a hydrocarbon.
Natural gas as a raw material gas is sent from the pipe 1 to the preheating furnace 2, where it is heated to 300 to 500 ° C., passed through the pipe 3, and sent to the desulfurizer 4. In the desulfurizer 4, the sulfur content accompanying the natural gas is removed by hydrogen introduced separately, and the desulfurized natural gas passes through the pipe 5 and joins with steam and carbon dioxide separately supplied from the pipes 6 and 13. Then, it is again introduced into the preheating furnace 2, heated to 500 to 600 ° C. and fed into the reactor 7. The (carbon dioxide + steam) / carbon ratio at the inlet of the reactor 7 is 1.3 to 2.5.
[0029]
Burners 8 and 8 are attached to the bottom of the reactor 7. Air is supplied from the pipe 9 and fuel (natural gas) is supplied from the pipe 10 to the burners 8 and 8, and the inside of the reactor 7 is reacted. It is designed to be kept at the temperature required.
The reactor 7 is provided with a catalyst bed 7a filled with the above reforming catalyst.
As the form of the catalyst bed 7a, any form such as a fixed bed, a moving bed, and a fluidized bed can be selected. The space velocity of the source gas is in the range of 500 to 200000 / Hr, preferably 1000 to 100000 / Hr, more preferably 1000 to 70000 / Hr.
The temperature at the outlet of the reactor 7 is 750 to 950 ° C., preferably 850 to 900 ° C., and the pressure is 5 to 40 kg / cm ² , preferably 15 to 25 kg / cm ² .
[0030]
The synthesis gas-containing gas (hereinafter also referred to as reformed gas) obtained after the reaction has a temperature of 750 to 950 ° C. and a pressure of 5 to 40 kg / cm ² , and carbon monoxide and hydrogen, that is, synthesis gas is about The reformed gas occupies 80 vol% and the remainder is unreacted or by-produced carbon dioxide, water vapor, and methane, and this reformed gas is sent from the reactor 7 through the pipe 11 to the first heat exchanger 12, and the heat is recovered. Is done.
[0031]
The reformed gas cooled to 350 to 450 ° C. in the first heat exchanger 12 is then sent from the pipe 14 to the second heat exchanger 15 where heat is further recovered and cooled to the separation tank 16. Sent. In the separation tank 16, moisture in the gas is condensed and removed.
[0032]
The gas from which moisture has been removed passes through the pipe 17 and is supplied to a production process such as DME synthesis, FT synthesis, or methanol synthesis using synthesis gas as a raw material.
Here, the supply ratio of carbon dioxide and steam to the reactor 7 is (carbon dioxide + steam) / carbon ratio within the range of 1.3 to 2.5, depending on the type of manufacturing process to which the gas is supplied. It is preferable to adjust the composition of the synthesis gas-containing gas led out from the reactor 7.
[0033]
For example, when the gas from which moisture has been removed is supplied to the DME synthesis apparatus, the (carbon dioxide + steam) / carbon ratio at the inlet of the reactor 7 is adjusted to about 1.3 to 1.8, The hydrogen / carbon monoxide ratio in the reformed gas is preferably 0.9 to 2.2. When the gas from which moisture has been removed is supplied to the FT synthesizer, the hydrogen / carbon monoxide ratio is adjusted by adjusting the (carbon dioxide + steam) / carbon ratio to about 1.3 to 2.2. It is preferable to set it as 0.9-2.2. Furthermore, when the gas from which moisture has been removed is supplied to the methanol synthesizer, the (carbon dioxide + steam) / carbon ratio is adjusted to about 1.4 to 2.5, and (hydrogen-carbon dioxide) / The (carbon monoxide + carbon dioxide) ratio is preferably 1.8 to 2.2.
[0034]
On the other hand, pure water is sent from the pipe 20 to the second heat exchanger 15, heated here, and sent to the steam drum 21. And it is further heated by the heat | fever collect | recovered with the 1st heat exchanger 12 in the steam drum 21, becomes a steam with the temperature of 180-310 degreeC, and a pressure of 10-100 kg / cm < ² >, passes the pipe | tube 6, the pipe | tube 5, The raw material natural gas and carbon dioxide flowing through the mixture 13 are mixed and sent to the preheating furnace 2. Excess steam is branched from the pipe 22 and discharged out of the system.
[0035]
FIG. 4 shows an apparatus for carrying out a second example of the synthesis gas production method of the present invention.
In this example, hydrocarbons having 3 to 8 carbon atoms, such as oil field associated gas, naphtha, and heavy oil, and mixtures thereof (referred to as heavy hydrocarbons in the present invention) are used as raw material hydrocarbons. In this example, explanation will be made with an example using naphtha.
In the manufacturing method of this example, naphtha is introduced into a preconverter in advance and preliminarily converted into light hydrocarbons having 2 or less carbon atoms and then sent to the reactor. For this reason, in FIG. 4, the same components as those shown in FIG.
[0036]
The raw material naphtha is sent from the pipe 1 to the preheating furnace 2, heated to be gaseous, and sent from the pipe 3 to the desulfurizer 4, where the sulfur component accompanying the hydrogen introduced separately is desulfurized. The Naphtha from the desulfurizer 4 is sent again from the pipe 5 to the preheating furnace 2, and at this time, steam from the pipe 6 is mixed therewith. The mixture of naphtha and steam heated to a temperature of 400 to 550 ° C. in the preheating furnace 2 is sent to the pre-converter 25.
[0037]
The preconverter 25 is filled with a known nickel-based catalyst so that the conversion reaction proceeds under conditions of a temperature of 400 to 550 ° C., a pressure of 5.5 to 55 kg / cm ² , and a steam / carbon ratio of 1 to 4. Where naphtha is converted to low-quality hydrocarbon methane. The low-quality hydrocarbons derived from the preconverter 25 are sent again from the pipe 23 to the preheating furnace 2. At this time, steam from the pipe 24 branched from the pipe 6 and carbon dioxide from the pipe 13 are mixed therewith. A mixed gas of low-quality hydrocarbon, steam and carbon dioxide is heated again in the preheating furnace 2 and supplied to the reactor 7.
The processing operation after the reactor 7 is the same as the example of the natural gas.
[0038]
In such a synthesis gas production method, since the above-mentioned highly active reforming catalyst is used in the reforming reaction, low-cost operation is possible as reaction conditions, and the equipment cost can be reduced ( Even under the reaction conditions of carbon dioxide + steam) / carbon ratio of about 1.5, temperature of about 900 ° C., and pressure of about 20 kg / cm ² , there is no precipitation of carbonaceous matter, and synthesis gas can be produced stably for a long period of time.
[0039]
Further, since the activity of the reforming catalyst is high, the carbon dioxide + steam / carbon ratio is 1.3 to 2.5, the temperature is 750 to 950 ° C., and the pressure is 5 to 40 kg / cm ² . However, the reforming reaction can proceed well without causing carbonaceous precipitation. For this reason, according to the method for producing a synthesis gas of the present invention, it is possible to reduce operating costs and equipment costs.
[0040]
Specific examples are shown below, but the present invention is not limited to these specific examples.
(1) Preparation Example of Reforming Catalyst 1.62 kg of cobalt nitrate hexahydrate and 27.1 kg of magnesium nitrate hexahydrate were dissolved in 50 L of water. Then, while maintaining the solution temperature at 50 ° C., the pH was adjusted to 9 by adding 59 L of 2mo1 / L calcium carbonate aqueous solution, and a precipitate composed of two components of cobalt and magnesium was generated. The precipitate was filtered and washed. It was dried in air at 120 ° C. for 12 hours or more. Subsequently, it baked at 450 degreeC in the air for 4 hours, and the primary baked material was obtained. This was molded and then calcined in air at 1180 ° C. for 5 hours to obtain a catalyst.
[0041]
(2) Production Example 1
The reforming catalyst 4L obtained in the above preparation example was filled into a flow-type reaction tube having an inner diameter of 50 mm and an effective length of 2000 mm to obtain a reactor. After the catalyst was activated by flowing hydrogen into the reactor in advance at a temperature of 700 ° C., methane, carbon dioxide and steam were fed under the following conditions. The reactor outlet temperature was 900 ° C. and the pressure was 20 kg / cm ² .
・ Steam / carbon ratio = 0.72
Carbon dioxide / carbon ratio = 0.2
・ (Carbon dioxide + steam) / carbon ratio = 0.92
・ Methane supply amount = 5 Nm ³ / hour ・ Steam supply amount = 3.6 Nm ³ / hour ・ Carbon dioxide supply amount = 1.0 Nm ³ / hour ・ Reactor inlet temperature = 550 ° C.
[0042]
The results of the reaction are shown in Table 1. In Table 1, the “calorific value unit” is obtained by multiplying the total amount of raw material methane and fuel methane by the calorific value and dividing this by the generation amount of synthesis gas (hydrogen + carbon monoxide). The “heat recovery system facility capacity” is the same as the heat recovery system (steam generator) capacity divided by the amount of synthesis gas generated.
[0043]
[Table 1]

[0044]
(3) Production Examples 2-4
In Production Example 1, the reaction was carried out by changing the supply amount of steam and carbon dioxide, changing the (carbon dioxide + steam) / carbon ratio, and other conditions being the same. The results are shown in Table 1.
[0045]
From the results shown in Table 1, when the steam / carbon ratio is 1.08 and the carbon dioxide / carbon ratio is 0.42, that is, the (carbon dioxide + steam) / carbon ratio is 1.5, the calorific value, the heat recovery system capacity It has been found that the most economical synthesis gas can be produced. It is also clear that no carbonaceous precipitation occurs at a (carbon dioxide + steam) / carbon ratio of 3 or less.
[0046]
【The invention's effect】
As described above, according to the manufacturing method of synthesis gas of the present invention, CoO, and at least one of MgO or MgO / CaO composite oxide of Ni O, Co, breaks were highly dispersed at least one Ni Since the catalyst for quality is used to obtain synthesis gas from hydrocarbon, carbon dioxide and steam by rehoming reaction, there is no precipitation of carbonaceous matter even in the reaction conditions where the operating cost and equipment cost are the lowest. Manufacture can be performed stably for a long time.
[0047]
In addition, if a pre-conversion process is provided in the previous stage to convert heavy hydrocarbons such as naphtha into light hydrocarbons such as methane and react them with steam, heavy hydrocarbons can be used as a raw material without any problems. it can.
Furthermore, if the heat | fever of the synthesis gas containing gas from a reactor is collect | recovered and it becomes a heat source of a steam, an operating cost can be reduced.
Further, by adjusting the supply ratio of carbon dioxide and steam to the reactor, and adjusting the composition of the synthesis gas-containing gas derived from the reactor according to the type of the latter process using the synthesis gas, the latter stage The manufacturing cost of the entire process including the process can be reduced.
[Brief description of the drawings]
FIG. 1 is a chart showing the relationship between reaction pressure and (carbon dioxide + steam) / carbon ratio when a conventional reforming catalyst is used.
FIG. 2 is an explanatory view schematically showing a surface state of a catalyst used in the present invention.
FIG. 3 is a schematic configuration diagram of an apparatus used in an example of a method for producing synthesis gas according to the present invention.
FIG. 4 is a schematic configuration diagram of an apparatus used in another example of the synthesis gas production method of the present invention.
[Explanation of symbols]
7 ... Reactor, 12 ... First heat exchanger, 21 ... Steam drum, 25 ... Pre-converter

Claims (6)

A process for producing synthesis gas by reacting hydrocarbon, carbon dioxide and steam in a reactor in the presence of a reforming catalyst,
(Carbon dioxide + steam) / carbon ratio at the reactor inlet is 1.3-2.5, temperature at the reactor outlet is 750-950 ° C., pressure is 5-40 kg / cm ² ,
A synthesis characterized in that the reforming catalyst is made of a composite oxide having a composition represented by the following formula, and at least one of Co and Ni is highly dispersed in the composite oxide How to make gas.
b Co · cNi · dMg · eCa · fO
( Wherein b , c, d, e are mole fractions , b + c + d + e = 1 , 0.001 ≦ (b + c) ≦ 0.3, 0 ≦ b ≦ 0.3, 0 ≦ c ≦ 0.3) 0.6 ≦ (d + e) ≦ 0.999, 0 <d ≦ 0.999, 0 ≦ e ≦ 0.999, and f = the number necessary for the element to maintain a charge balance with oxygen . When the hydrocarbon is a heavy hydrocarbon having 3 to 8 carbon atoms, a pre-reforming step is provided in the previous stage, and the heavy hydrocarbon is converted into a light hydrocarbon having 2 or less carbon atoms in advance to react. The method for producing synthesis gas according to claim 1, wherein the synthesis gas is sent to a vessel. The method for producing a synthesis gas according to claim 1 or 2, wherein the heat of the synthesis gas-containing gas derived from the reactor is recovered, steam is generated by this heat, and the steam is sent to the reactor. The composition of the synthesis gas-containing gas led out from the reactor is adjusted by adjusting the supply ratio of carbon dioxide and steam to the reactor, and the synthesis gas according to any one of claims 1 to 3, Manufacturing method. The supply ratio of carbon dioxide and steam to the reactor is adjusted so that the hydrogen / carbon monoxide ratio in the synthesis gas-containing gas derived from the reactor is 0.9 to 2.2. 4. A method for producing a synthesis gas according to 4. Supply carbon dioxide and steam to the reactor so that the (hydrogen-carbon dioxide) / (carbon monoxide + carbon dioxide) ratio in the synthesis gas-containing gas derived from the reactor is 1.8 to 2.2 The method for producing a synthesis gas according to claim 4, wherein the ratio is adjusted.

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