CN118236997A - Desorption regeneration method and system of VOCs adsorbent - Google Patents
Desorption regeneration method and system of VOCs adsorbent Download PDFInfo
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- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/30—Processes for preparing, regenerating, or reactivating
- B01J20/34—Regenerating or reactivating
- B01J20/3483—Regenerating or reactivating by thermal treatment not covered by groups B01J20/3441 - B01J20/3475, e.g. by heating or cooling
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/02—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography
- B01D53/04—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols by adsorption, e.g. preparative gas chromatography with stationary adsorbents
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- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/10—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising silica or silicate
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- B01J20/00—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof
- B01J20/02—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material
- B01J20/20—Solid sorbent compositions or filter aid compositions; Sorbents for chromatography; Processes for preparing, regenerating or reactivating thereof comprising inorganic material comprising free carbon; comprising carbon obtained by carbonising processes
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Abstract
The invention relates to a desorption regeneration method of VOCs adsorbent, which adopts an adsorption method to treat VOCs waste gas, adopts a thermal oxidation method to carry out cyclic thermal desorption regeneration treatment on an adsorption tank penetrated by adsorption, and divides the thermal desorption regeneration period into a regeneration initial stage, a cyclic regeneration period and a regeneration final stage: the method comprises the steps of firstly, replacing a regeneration adsorption tank in the initial period of regeneration, and controlling the oxygen concentration in the circulating gas to be not more than the limiting oxygen concentration of the combustible component after replacement; feeding oxygen to the cyclic desorption gas of the thermal oxidation device in a cyclic regeneration period, controlling the concentration of the oxygen to be 1% -3% in the cyclic desorption gas of the thermal oxidation device, and when the oxygen replenishment quantity approaches 0, increasing the temperature of the cyclic regeneration gas by 10-50 ℃ until the temperature is increased to 300-400 ℃, and feeding the cyclic regeneration gas into the end stage of regeneration; and at the end of regeneration, inert gas and air are adopted to cool the adsorbent. The invention can avoid potential safety hazard caused by easy deflagration of combustible gas in the desorption and regeneration process of VOCs adsorbent, realize deep desorption and regeneration of adsorbent, improve desorption efficiency and reduce desorption and regeneration energy consumption.
Description
Technical Field
The invention belongs to the technical field of environmental protection waste gas treatment, and particularly relates to a desorption regeneration method and system of VOCs adsorbent.
Background
Volatile Organic Compounds (VOCs) are important components of atmospheric pollutants, VOCs can generate photochemical reaction with nitrogen oxides under illumination conditions to generate ozone, and are also important precursors of PM2.5 secondary particles, so that the VOCs are important points for preventing and treating atmospheric pollution in recent years. Petrochemical industry such as petroleum refining, petrochemical industry, synthetic resin, and the like, chemical industry such as organic chemical industry, coal chemical industry, coking, pharmacy, pesticide, paint, printing ink, adhesive, and the like, relates to industry coated automobiles, furniture, parts, steel structures, color coated plates, and the like, and generates a large amount of VOCs waste gas in the production operation process, and proper treatment measures are adopted to meet the corresponding environmental protection standard limit value requirements.
Common VOCs treatment technologies include an adsorption method, an absorption method, a condensation method, a membrane separation method, a thermal oxidation method and the like, and one or more combination technologies are generally adopted to realize economic and efficient treatment of the VOCs according to the characteristics of pollution sources. The adsorption method has the advantages of high efficiency, low cost, low energy consumption, flexible operation and the like, and is widely applied to industrial VOCs treatment alone or in combination with other technologies. The adsorbent materials used in industry are generally required to have large specific surface area, porosity and adsorption capacity, to be selective for different gas adsorption, to be easily regenerated, and to have high mechanical strength and thermal stability. The adsorption materials studied and applied at present mainly comprise carbon-based materials, molecular sieves, resins, metal organic frameworks and the like, wherein the carbon-based materials such as activated carbon, activated carbon fibers and the like are most widely applied.
The adsorbent has excellent adsorption performance, but whether the adsorbent can be quickly and efficiently desorbed and regenerated is a key to influence the industrial application of the adsorbent. Common adsorbent regeneration techniques include thermal regeneration, vacuum regeneration, displacement desorption regeneration, solvent extraction regeneration, and the like. The heating regeneration is widely applied to industrial waste gas treatment, and generally, the higher the temperature is, the more thorough the regeneration is. Vacuum regeneration is to desorb substances adsorbed in the adsorbent pore channels under vacuum conditions, and generally requires a higher vacuum level. However, the vacuum regeneration generally does not thoroughly heat and regenerate high temperature, especially high boiling point macromolecular organic matters, and the heat and high temperature regeneration has better effect, so the heat and high temperature regeneration is often needed after the vacuum regeneration is performed for several times. According to different heating media and heating modes, the heating regeneration mainly adopts modes such as hot air, hot inert gas, superheated steam, microwave heating, electric heating and the like to carry out desorption regeneration on the adsorbent.
CN110141932a discloses an oil gas recovery process system, which comprises a VOC gas inlet, a VOC purification recovery unit, a nitrogen gas circulation system unit, a refrigeration system unit, and a condensate tank; the VOC purifying and recycling unit comprises a plurality of adsorption towers, wherein any one of the adsorption towers can be in a VOC adsorption state, the other adsorption towers perform corresponding steps of adsorption, replacement, heating, cooling and the like, and the adsorption towers alternately and circularly work; the nitrogen circulation system unit provides a nitrogen source for the adsorption tower; the refrigerating system unit provides a refrigerant for the VOC purifying and recycling unit; the condensate storage tank is used for recycling liquid organic matters. The patent adopts a heating regeneration method to regenerate the adsorbent, specifically adopts an electric heating mode to heat nitrogen to regenerate the adsorbent, and has higher energy consumption.
CN101721833a discloses a method for condensing, adsorbing, recovering and purifying hydrocarbon-containing waste gas, wherein activated carbon is used for adsorption-regeneration treatment of waste gas after pretreatment of condensing, dewatering and recovering hydrocarbon, a mode of combining normal pressure and vacuum desorption is used for regeneration of activated carbon, and a steam heating regeneration gas source is used for compensating for the temperature reduction of regenerated gas caused in the desorption process of organic matters. Inert gas such as nitrogen can be supplemented in the regeneration process of the invention, and the temperature is 100-250 ℃.
CN108744852a discloses an organic waste gas treatment system, which comprises an adsorption system, a fan, a flowmeter, an adsorption device, an adsorption tower, a heating regeneration loop system, a nitrogen source, an electric heater, a heat exchanger, a pressurizing storage tank, a booster pump, a condensation recovery system, a primary condenser, a secondary condenser, a tertiary condenser, a gas-liquid separator and a liquid storage tank, wherein the fan, the flowmeter, the adsorption device and the adsorption tower are arranged in the adsorption device. Compared with the prior art, the organic waste gas treatment adsorbent can be heated and regenerated by adopting the heating and regenerating loop system, and the organic solvent can be recycled by adopting the condensation recycling system. However, the invention adopts electric heating program to raise the temperature by 25-500 ℃, and adopts nitrogen heating as a regeneration air source, so that the energy consumption is high.
Because the adsorbent adsorbs a large amount of VOCs, directly adopts hot air to regenerate, has great potential safety hazard, in order to overcome this problem, adopts nitrogen gas or inert gas as the air supply in the prior art mostly, needs to set up electric heater or steam heating, and the energy consumption is higher, and the regeneration gas that the desorption produced returns preceding absorption, condensation, membrane separation etc. unit and organic waste gas and retrieves together, because there is great fluctuation in organic matter concentration in the regeneration gas, can lead to front end exhaust treatment unit fluctuation and influence waste gas comprehensive treatment effect. In addition, most of the VOCs treated in industry are mixed components, and the recovered organic matters still need to be separated and refined for use or used as fuel, which is not generally economical.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a desorption regeneration method and a system of a VOCs adsorbent. The invention can avoid potential safety hazard caused by easy deflagration of combustible gas in the desorption and regeneration process of VOCs adsorbent, realize deep desorption and regeneration of adsorbent, improve desorption efficiency and reduce desorption and regeneration energy consumption.
In one aspect, the invention provides a desorption regeneration method of VOCs adsorbent, comprising the following steps:
The VOCs waste gas is treated by adopting an adsorption method, the adsorption tank penetrated by adsorption is subjected to cyclic thermal desorption regeneration treatment by adopting a thermal oxidation method, and high-temperature gas generated by thermal oxidation is used as cyclic gas to enter the adsorption tank for thermal desorption regeneration after heat is recovered, so that desorption regenerated gas is generated and is conveyed to a thermal oxidation device for treatment; before the thermal desorption regeneration operation, a thermal standby operation of the thermal oxidation device is established; the thermal desorption regeneration period is divided into a regeneration initial stage, a cyclic regeneration period and a regeneration final stage: the method comprises the steps of firstly replacing a regeneration adsorption tank in the initial period of regeneration, mixing the replacement gas with waste gas for adsorption treatment, controlling the oxygen concentration in circulating gas to be not more than the limiting oxygen concentration of combustible components after replacement, preferably 1% -3%, and heating the temperature of an adsorbent bed to 100-120 ℃; entering a cyclic regeneration period, along with the thermal oxidation of VOCs desorption and desorption regeneration gas, supplementing oxygen to the cyclic desorption gas of a thermal oxidation device, controlling the concentration of the cyclic desorption gas of the thermal oxidation device to be 1% -3%, when the oxygen supplementing quantity approaches 0, increasing the temperature of the cyclic regeneration gas by 10-50 ℃, preferably 20-30 ℃, and controlling the thermal desorption regeneration process according to the temperature until the temperature of the cyclic regeneration gas is increased to 300-400 ℃, and when the oxygen supplementing quantity approaches 0 and the hydrocarbon concentration is lower than 50mg/m 3, entering the regeneration terminal stage; and at the end of regeneration, inert gas and air are adopted to cool the adsorbent, and the thermal desorption regeneration of the adsorption tank is finished.
In the method of the invention, the adsorption method for treating VOCs waste gas generally comprises at least two adsorption tanks for performing adsorption-desorption regeneration switching operation. The adsorption tank can be designed into a fixed bed, a fluidized bed and other bed layers. The adsorption tank is filled with VOCs adsorbent, and the adsorbent can be at least one of carbon-based material, molecular sieve, resin and the like, or can be an adsorption bed layer formed by combining and grading the various adsorbents. The carbon-based material may be at least one of activated carbon, activated carbon fiber, and the like. The volume space velocity of the exhaust gas passing through the adsorbent is generally 100 to 5000h -1.
In the method, the adsorption penetration means that the concentration of VOCs in the purified gas at the outlet of the adsorption tank reaches the set adsorption penetration concentration, the set value of the adsorption penetration concentration is generally not higher than 120mg/m 3 according to the environmental protection index requirement, the concentration of VOCs in the purified gas at the outlet under the normal adsorption working condition is lower than the value, and the adsorption penetration is considered if the concentration is close to or reaches the value. When the concentration of the purified gas at the outlet of one adsorption tank reaches the set adsorption penetration concentration, switching operation is carried out, and thermal desorption regeneration is carried out on the adsorption tank penetrated by adsorption. When fixed bed adsorption is adopted, the gas flow directions of the adsorption and thermal desorption regeneration of the waste gas containing VOCs are opposite.
In the method of the present invention, the temperature of the thermal desorption regeneration of the adsorption tank is generally 80 to 500 ℃, preferably 100 to 400 ℃, according to the composition of the adsorbed organic matter. The temperature of the thermal desorption regeneration of the adsorption tank is gradually increased by adjusting the temperature of the circulating regeneration gas, so that the process of the thermal desorption regeneration is controlled.
In the method, the produced desorption regenerated gas is treated by adopting a thermal oxidation method, and mainly comprises a thermal oxidation unit, and can adopt catalytic oxidation, thermal storage oxidation, thermal incineration and the like, and a catalytic oxidation device provided with a heat exchanger and a heater or a thermal storage oxidation device provided with a thermal storage body is preferably adopted. VOCs-containing waste gas enters a thermal oxidation device through an induced draft fan, is oxidized into CO 2 and H 2 O, emits heat, discharges high-temperature gas from the thermal oxidation device, and recovers heat through a heat recovery facility.
In the method, before the thermal desorption regeneration operation, the thermal oxidation unit is in thermal standby operation, and the thermal oxidation device reaches the temperature of normal operation. If a catalytic oxidation device is used, the temperature of the exhaust gas at the inlet of the reactor is generally not lower than 250 ℃, preferably 300-450 ℃, and the temperature of the exhaust gas at the outlet is 350-650 ℃, preferably 400-550 ℃. If a regenerative oxidation device is adopted, the temperature of the combustion chamber is higher than 760 ℃.
In the method, the thermal desorption regeneration period is divided into three stages of the initial regeneration period, the cyclic thermal regeneration period and the final regeneration period, and the total thermal desorption regeneration period time is smaller than the total adsorption time.
In the method of the invention, the limiting oxygen concentration is the limiting oxygen concentration of the adsorbent and the adsorbed VOCs component, and if the adsorbed VOCs are mixed components, the oxygen concentration of the thermal desorption regeneration recycle gas is not more than the limiting oxygen concentration of the lowest component of the limiting oxygen concentration, preferably not more than 1-3%.
In the method of the present invention, if the oxygen concentration in the exhaust gas of VOCs is higher than the limiting oxygen concentration, the replacement operation is required at the early stage of the regeneration, and the replacement is performed by using an inert gas such as CO 2、N2 or the like. And mixing the replacement gas with the waste gas containing VOCs to be treated for adsorption treatment, introducing high-temperature circulating gas to heat the adsorbent bed after the replacement is carried out until the oxygen concentration meets the requirement of circulating regeneration oxygen concentration, and heating the adsorbent bed to 80-120 ℃.
In the method, a heat recovery facility such as a heat exchanger, a steam generator and the like is arranged to recover heat released by the oxidation of the organic matters of the thermal oxidation unit, a bypass of the heat recovery facility is arranged, and the air quantity of an outlet of the thermal oxidation unit and the bypass of the heat recovery facility is regulated according to the heat required for heating the adsorbent bed layer to the target thermal desorption regeneration temperature, so that the temperature of the circulating regeneration gas entering the adsorption tank is controlled.
In the method of the present invention, the amount of circulating regenerated gas in the initial stage of regeneration is 30% to 70%, preferably 40% to 60% of the treatment scale of the thermal oxidation apparatus.
In the method, at the end of regeneration, the adsorbent bed is subjected to cooling treatment, a cold inert gas such as nitrogen or CO 2 and the like is adopted to cool the adsorption tank after thermal desorption regeneration, and when the temperature is reduced to below 200 ℃, preferably below 150 ℃, a large amount of air is adopted to cool to the normal adsorption operation temperature.
In the method, after the thermal desorption regeneration is finished, part of high-concentration CO 2 gas is discharged for CO2 capture and utilization, and the rest 30% -70% is switched to the next adsorption tank to be desorbed and regenerated, or enters a thermal standby circulation state to wait for the next adsorption tank to be desorbed and regenerated. And in a thermal standby circulation state of the thermal oxidation device, the gas circulates through the thermal oxidation device under the driving of the fan, and the heat loss of the system is supplemented through the heater. If the thermal regeneration operation of the adsorbent is not performed for a long period of time, generally more than 24 hours, it is considered to stop the operation of the thermal oxidation apparatus.
The waste gas containing VOCs is various VOCs organic waste gas produced in industries such as petrochemical industry, coating and printing and dyeing, and the like, and according to the characteristics of pollutant composition, concentration, emission rule and the like in the waste gas, the waste gas containing VOCs is recycled after the technology such as absorption, condensation and membrane separation is adopted, and then the waste gas is treated by an adsorption technology, so that the corresponding environmental protection treatment requirements are met.
Compared with the prior art, the invention has the following outstanding characteristics:
According to the invention, the thermal desorption regeneration period is divided into a regeneration initial stage, a cyclic regeneration period and a regeneration final stage, and the oxygen concentration in the adsorbent cyclic thermal desorption regeneration gas and the desorption temperature of the adsorbent bed layer are regulated and controlled to control the extent of the adsorbent thermal desorption and the organic thermal oxidation, so that the risk that high-concentration organic combustible gas is easy to deflagrate or flash in the thermal desorption regeneration process is avoided, and the safety of the adsorbent thermal desorption regeneration and desorption thermal oxidation is ensured. And the desorption regeneration gas is subjected to deep thermal oxidation treatment while the adsorbent is subjected to thermal desorption regeneration, and the oxidation heat is recycled in a steam production or material heating mode, so that the whole thermal regeneration process basically does not need additional supplementary heat, the energy consumption is low, and the VOCs treatment cost is greatly reduced. And the CO 2 can be enriched and trapped, so that the carbon emission is reduced.
The invention is especially suitable for the efficient desorption and regeneration of the adsorbent for VOCs adsorption treatment generated in the industries of petrochemical industry, coating, printing and dyeing and the like, and especially for the separate adsorption treatment of dispersed multiple pollution sources or multiple pollution sources in an industrial park and the centralized heat regeneration treatment. Has the advantages of safety, stability, high efficiency, green low carbon and good economical efficiency.
Detailed Description
The method of the present invention and the effects thereof will be described in detail with reference to specific examples. The embodiments and specific operation procedures are given on the premise of the technical scheme of the invention, but the protection scope of the invention is not limited to the following embodiments.
The experimental methods in the following examples, unless otherwise specified, are all conventional in the art. The experimental materials used in the examples described below, unless otherwise specified, were purchased from conventional biochemical reagent stores.
In the invention, on-line monitoring of temperature, VOCs (hydrocarbon concentration), oxygen concentration and water vapor concentration is provided.
In the method, firstly, the hot standby operation of the thermal oxidation unit is established, the thermal oxidation device reaches the temperature of normal operation, and when one of the adsorption tanks is adsorbed and penetrated, the thermal desorption regeneration is carried out. In the initial stage of regeneration, if the oxygen concentration in the adsorption tank to be regenerated is higher, firstly replacing the adsorption tank by using hot standby gas or CO 2 gas or N 2 of a thermal oxidation device, mixing the replacement gas with waste gas for adsorption treatment, controlling the oxygen concentration in the recycled regenerated gas to be not more than 3% after reducing the oxygen concentration, and heating the temperature of the adsorbent bed to 100-120 ℃; after entering a cyclic regeneration period and the cyclic desorption gas exits the adsorption tank, the oxygen concentration is regulated and controlled to be 1-3% by oxygen concentration monitoring, and the gas generated by a thermal oxidation device is preheated and enters a thermal oxidation unit under the driving of a fan; the organic matter is partially oxidized into CO 2 and H 2 O in a thermal oxidation unit, heat is released, and after high-temperature exhaust gas from an oxidation device is recovered through heat, the temperature is controlled and is conveyed to an adsorption tank, so that a thermal desorption regeneration cycle is established; along with the thermal oxidation of the VOCs desorption and desorption regeneration gas, when the oxygen supplementing quantity approaches 0, the temperature of the circulating regeneration gas entering the adsorption tank needs to be gradually increased, the temperature of the circulating regeneration gas is increased by 10-50 ℃ each time, preferably 20-30 ℃ until the temperature of the circulating regeneration gas reaches 300-400 ℃, and when the oxygen supplementing quantity approaches 0 for a long time or the concentration of the VOCs is stably less than 50mg/m < 3 >, the circulating thermal desorption is ended. Cutting into the next adsorption tank or thermal oxidation unit to be desorbed and regenerated, and performing low-power-consumption cyclic hot standby operation. N 2 or CO 2 gas is adopted to cool the adsorption tank, and after the temperature is reduced to be lower than 150 ℃, large-air-volume air or adsorption exhaust gas is adopted to continuously cool the adsorbent to the adsorption operation temperature, and then the whole desorption regeneration process of the adsorbent is completed.
Example 1
The waste gas of a biochemical aeration tank and an oxidation ditch of a sewage treatment plant of a certain refining enterprise is treated by an adsorption technology, the waste gas quantity is 20000Nm 3/h, the waste gas concentration is 80-400 mg/m 3, the total non-methane hydrocarbon concentration of the gas after the adsorption treatment is controlled to be less than 60mg/m 3, two adsorption tanks are arranged, the adsorbent is coal-based activated carbon, the packing quantity of a single adsorption tank is about 30m 3, the penetrating adsorption capacity (according to the penetrating concentration of 60mg/m 3) is about 4% (mass fraction), and the adsorption-regeneration switching period is about one week. The volumetric space velocity of the exhaust gas through the adsorbent is about 666h -1.
The process and the device of the invention are adopted to carry out cyclic thermal regeneration on the adsorbent which is absorbed and penetrated, the thermal oxidation device is a catalytic oxidation device, and the design scale of the catalytic oxidation device is 5000Nm 3/h.
Before the cyclic thermal regeneration is started, the catalytic oxidation device circularly operates with low power consumption, the circulating gas is mainly CO 2, a small amount of gas is mixed into a small amount of N 2, the adsorption tank is replaced, and the replacement gas returns to the running adsorption treatment. After the replacement is finished, introducing the circulating regenerated gas into an adsorption tank, performing circulating thermal regeneration, wherein the circulating regenerated gas is 50% of the treatment scale of a thermal oxidation device, supplementing oxygen, controlling the oxygen concentration to be 2.5%, controlling the temperature to be 120 ℃, exchanging heat with high-temperature gas discharged by catalytic oxidation, entering a catalytic oxidation reactor, oxidizing part of organic matters into CO 2 and H 2 O at the inlet temperature of the reactor under the action of a catalyst, preheating the circulating regenerated gas and producing steam at the outlet temperature of about 450-500 ℃, and controlling the temperature of the circulating regenerated gas entering the adsorption tank. Gradually increasing the temperature of the circulating regeneration gas, wherein the temperature is about 20 ℃ each time, and the temperature of the final adsorbent bed is stabilized at 350 ℃. When the oxygen supplementing amount is basically 0 within 15 minutes, the hydrocarbon concentration in the circulating regenerated gas is lower than 50mg/m < 3 >, and the thermal desorption of the adsorbent is completed. The adsorbent is then cooled with nitrogen, and after the temperature has fallen to 150 ℃, the adsorbed purge gas is further cooled to ambient temperature for further use, typically for about 3-5 days throughout the regeneration process. And (3) condensing and removing water by discharging part of gas, and returning the rest gas mainly comprising CO 2 to a circulating system, wherein the content of H 2 O in the circulating regeneration gas is controlled to be not higher than 20%. After regeneration, the discharged part of the circulating gas mainly containing CO2 is used for preparing dry ice.
After 3 months of operation, no early warning of deflagration or flash explosion of combustible gas occurs, the exhaust gas after the adsorbent is recycled meets the limit value requirement, the regeneration process basically does not need additional supplementary heat, and only in the regeneration waiting interval or switching process, the electric heater supplements a small amount of supplementary heat to compensate the heat loss of the system.
Claims (12)
1. A desorption regeneration method of VOCs adsorbent is characterized by comprising the following steps: the VOCs waste gas is treated by adopting an adsorption method, the adsorption tank penetrated by adsorption is subjected to cyclic thermal desorption regeneration treatment by adopting a thermal oxidation method, and high-temperature gas generated by thermal oxidation is used as cyclic gas to enter the adsorption tank for thermal desorption regeneration after heat is recovered, so that desorption regenerated gas is generated and is conveyed to a thermal oxidation device for treatment; before the thermal desorption regeneration operation, a thermal standby operation of the thermal oxidation device is established; the thermal desorption regeneration period is divided into a regeneration initial stage, a cyclic regeneration period and a regeneration final stage: the method comprises the steps of firstly replacing a regeneration adsorption tank in the initial period of regeneration, mixing the replacement gas with waste gas for adsorption treatment, controlling the oxygen concentration in circulating gas to be not more than the limiting oxygen concentration of combustible components after replacement, preferably 1% -3%, and heating the temperature of an adsorbent bed to 100-120 ℃; entering a cyclic regeneration period, along with the thermal oxidation of VOCs desorption and desorption regeneration gas, supplementing oxygen to the cyclic desorption gas of a thermal oxidation device, controlling the concentration of the cyclic desorption gas of the thermal oxidation device to be 1% -3%, when the oxygen supplementing quantity approaches 0, increasing the temperature of the cyclic regeneration gas by 10-50 ℃, preferably 20-30 ℃, and controlling the thermal desorption regeneration process according to the temperature until the temperature of the cyclic regeneration gas is increased to 300-400 ℃, and when the oxygen supplementing quantity approaches 0 and the hydrocarbon concentration is lower than 50mg/m 3, entering the regeneration terminal stage; and at the end of regeneration, inert gas and air are adopted to cool the adsorbent, and the thermal desorption regeneration of the adsorption tank is finished.
2. The method according to claim 1, characterized in that: the adsorption method for treating the VOCs waste gas comprises at least two adsorption tanks, and adsorption-desorption regeneration switching operation is carried out; the adsorption tank is a fixed bed or a fluidized bed, VOCs adsorbent is filled in the adsorption tank, and the adsorbent is at least one of carbon-based material, molecular sieve and resin, or an adsorption bed layer formed by combining and grading the above adsorbents.
3. The method according to claim 1, characterized in that: the adsorption penetration means that the concentration of VOCs in the purified gas at the outlet of the adsorption tank reaches the set adsorption penetration concentration, the set value of the adsorption penetration concentration is not higher than 120mg/m 3 according to the environmental protection index requirement, the concentration of VOCs in the purified gas at the outlet under the normal adsorption working condition is lower than the value, and the adsorption penetration is considered if the concentration is close to or reaches the value; when the concentration of the purified gas at the outlet of one adsorption tank reaches the set adsorption penetration concentration, switching operation is carried out, and thermal desorption regeneration is carried out on the adsorption tank penetrated by adsorption; when fixed bed adsorption is adopted, the gas flow directions of the adsorption and thermal desorption regeneration of the waste gas containing VOCs are opposite.
4. The method according to claim 1, characterized in that: according to the composition condition of the adsorbed organic matters, the thermal desorption and regeneration temperature of the adsorption tank is 80-500 ℃, preferably 100-400 ℃; the temperature of the thermal desorption regeneration of the adsorption tank is gradually increased by adjusting the temperature of the circulating regeneration gas, so that the process of the thermal desorption regeneration is controlled.
5. The method according to claim 1, characterized in that: the thermal oxidation treatment mainly comprises a thermal oxidation unit, catalytic oxidation, thermal storage oxidation and thermal incineration, wherein a catalytic oxidation device provided with a heat exchanger and a heater or a thermal storage oxidation device provided with a thermal storage body is preferably adopted; before the thermal desorption regeneration operation, the thermal oxidation unit has completed the thermal standby operation, and the thermal oxidation device has reached the temperature of normal operation.
6. The method according to claim 1, characterized in that: the catalytic oxidation device is adopted, the temperature of the exhaust gas at the inlet of the reactor is generally not lower than 250 ℃, preferably 300-450 ℃, and the temperature of the exhaust gas at the outlet is 350-650 ℃, preferably 400-550 ℃; by adopting a regenerative oxidation device, the temperature of the combustion chamber is higher than 760 ℃.
7. The method according to claim 1, characterized in that: the thermal desorption regeneration period is divided into three stages of a regeneration initial stage, a cyclic thermal regeneration and a regeneration final stage, and the total thermal desorption regeneration period time is smaller than the total adsorption time.
8. The method according to claim 1, characterized in that: the limiting oxygen concentration is the limiting oxygen concentration of the adsorbent and the adsorbed VOCs component, and if the adsorbed VOCs are mixed components, the oxygen concentration of the thermal desorption regeneration recycle gas is not more than the limiting oxygen concentration of the lowest component of the limiting oxygen concentration, preferably not more than 1-3%.
9. The method according to claim 1, characterized in that: if the oxygen concentration in the VOCs waste gas is higher than the limiting oxygen concentration, the replacement operation is needed in the early stage of regeneration, and inert gas such as CO 2、N2 is adopted for replacement; and mixing the replacement gas with the waste gas containing VOCs to be treated for adsorption treatment, introducing high-temperature circulating gas to heat the adsorbent bed after the replacement is carried out until the oxygen concentration meets the requirement of circulating regeneration oxygen concentration, and heating the adsorbent bed to 80-120 ℃.
10. The method according to claim 1, characterized in that: the amount of circulating regenerated gas in the initial period of regeneration is 30-70%, preferably 40-60% of the treatment scale of the thermal oxidation device.
11. A method according to claim 1, characterized in that at the end of the regeneration, the adsorbent bed is subjected to a temperature-reducing treatment, the adsorption tank after the thermal desorption regeneration is subjected to a temperature-reducing treatment with a cold inert gas such as nitrogen or CO 2, and when the temperature is reduced to below 200 ℃, preferably below 150 ℃, the temperature is reduced to the normal adsorption operating temperature with a large amount of air.
12. The method according to claim 1, characterized in that: after thermal desorption regeneration is finished, partial high-concentration CO 2 gas is discharged for CO 2 capture and utilization, and the rest 30% -70% is switched to the next adsorption tank to be desorbed and regenerated, or enters a thermal standby circulation state to wait for the next adsorption tank to be desorbed and regenerated.
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