Process for continuously regulating and controlling proportion of H2 / CO in synthesis gas

Abstract

The invention belongs to the technical field of synthesis gas treatment, and provides a process for continuously regulating and controlling the ratio of H2 to CO in synthesis gas. The process comprises the following steps: introducing mixed gas into a first adsorption tower, selectively adsorbing H2, CO2 and CO by a first adsorbent, and discharging H2, CO2 and CO as tail gas out of the first adsorption tower; introducing the tail gas discharged from the first adsorption tower into a second adsorption tower, selectively adsorbing CO by a second adsorbent, and carrying out subsequent treatment on residual CO2 as tail gas; carrying out desorption treatment on the first adsorption tower to obtain H2; carrying out desorption treatment on the second adsorption tower to obtain CO; after the desorption is completed, the first adsorption tower and the second adsorption tower are respectively recovered to corresponding adsorption conditions, and the next round of adsorption-desorption circulation is carried out. According to the process, efficient separation of H2 and CO can be achieved, the H2 / CO ratio can be continuously and stably regulated and controlled, and the performance of the adsorbent is excellent.

Description

Technical Field

[0001] This invention relates to the field of syngas treatment technology, and in particular to a process for continuous control of the H2 / CO ratio in syngas. Background Technology

[0002] Syngas (mainly composed of H2 and CO) is an important chemical feedstock, widely used in many chemical processes such as methanol synthesis, Fischer-Tropsch synthesis, and ammonia synthesis. Different chemical reactions have significantly different requirements for the H2 / CO ratio in syngas. For example, methanol synthesis requires an H2 / CO ratio of approximately 2:1, while Fischer-Tropsch synthesis requires a ratio between 1:1 and 2:1. Therefore, achieving precise and continuous control of the H2 / CO ratio in syngas is a crucial prerequisite for ensuring the efficient and stable operation of subsequent chemical processes.

[0003] Currently, the main technologies for controlling the H2 / CO ratio in syngas include shift reaction, membrane separation, and adsorption separation. Shift reaction adjusts the H2 and CO ratio through a shift reaction between CO and water, but this method has stringent reaction conditions and is difficult to control precisely over a wide range. Membrane separation offers advantages such as high separation efficiency and low energy consumption, but membrane materials are expensive, and long-term operation is prone to membrane fouling, affecting separation performance. Adsorption separation, based on the differences in adsorption properties of different gas components on adsorbents, is simple to operate and flexible in control, and has become a research hotspot in syngas separation and ratio control.

[0004] Existing adsorption separation technologies mostly employ a single adsorbent or a single-stage adsorption process, making it difficult to achieve efficient separation and recovery of H2 and CO simultaneously. Furthermore, they suffer from problems such as low precision in H2 / CO ratio control and inability to operate continuously. In addition, the selective adsorption performance of existing adsorbents for H2 or CO needs improvement, resulting in insufficient purity of the separated product gas, which affects subsequent applications.

[0005] Therefore, the research has yielded a continuous control process that can achieve efficient separation of H2 and CO, continuously and stably regulate the H2 / CO ratio, and exhibit excellent adsorbent performance, which has significant industrial application value. Summary of the Invention

[0006] The purpose of this invention is to provide a process for continuous control of the H2 / CO ratio in syngas, thereby resolving the problems of low precision in H2 / CO ratio control, inability to operate continuously, and insufficient purity of the separated product gas in existing technologies.

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a process for continuous control of the H2 / CO ratio in syngas, the process comprising the following steps: 1) The mixed gas is introduced into the first adsorption tower, where the first adsorbent selectively adsorbs H2, while CO2 and CO are discharged from the first adsorption tower as tail gas. 2) The exhaust gas discharged from the first adsorption tower is passed into the second adsorption tower. The second adsorbent selectively adsorbs CO, and the remaining CO2 is treated as exhaust gas for further processing. 3) The first adsorption tower is desorbed to obtain H2; 4) The second adsorption tower is desorbed to obtain CO; 5) After desorption is completed, the first adsorption tower and the second adsorption tower are restored to their respective adsorption conditions and enter the next adsorption-desorption cycle; The first adsorbent is filled in the first adsorption tower, and the second adsorbent is filled in the second adsorption tower.

[0008] Preferably, the mixed gas includes H2, CO and CO2.

[0009] Preferably, the preparation method of the first adsorbent includes the following steps: A. Activated carbon is placed in nitric acid solution and subjected to reflux and drying in sequence to obtain modified activated carbon; B. After mixing palladium source, copper source, modified activated carbon, additives and water, a binder is added to obtain strip-shaped particles; C. The strip-shaped particles are sequentially dried, calcined, and reduced to obtain the first adsorbent.

[0010] Preferably, in step A, the concentration of the nitric acid solution is 5-10 wt%, the reflux treatment temperature is 80-90°C, the reflux treatment time is 2-4 h, and the drying temperature is 110-120°C, and the drying time is 8-12 h. In step B, the palladium source is PdCl2, the copper source is Cu(NO3)2·3H2O, the additive is CeO2, and the binder is aluminum sol. The palladium and copper sources are referred to as active components, and the molar ratio of the palladium and copper sources is 1:2~4. The mass ratio of modified activated carbon, active components, additives, and binders is 50~70:20~35:3~8:2~5. The mixing includes ultrasonic mixing and stirring mixing. The ultrasonic mixing time is 30~60 min, the stirring mixing temperature is 60~80℃, and the stirring mixing time is 8~12 h. The diameter of the strip-shaped particles is 2~4 mm.

[0011] Preferably, in step C, the drying temperature is 110~120℃ and the drying time is 4~6h; the calcination is carried out under an inert atmosphere at a temperature of 350~450℃ for 2~3h; and the reduction is carried out under a hydrogen atmosphere at a temperature of 200~250℃ for 1~2h.

[0012] Preferably, the preparation method of the second adsorbent includes the following steps: a. After mixing the pretreated molecular sieve, nickel source, iron source, additives and ethanol aqueous solution, a binder is added to obtain spherical particles; b. The spherical particles are sequentially dried, calcined, and reduced to obtain the second adsorbent.

[0013] Preferably, in step a, the pretreatment is a calcination treatment at a temperature of 550-600℃ for 2-3 hours. The molecular sieve is ZSM-5, the nickel source is Ni(NO3)2·6H2O, the iron source is Fe(NO3)3·9H2O, the additive is ZrO2, the binder is silica sol, the volume ratio of ethanol to aqueous solution is 1:1, the nickel and iron sources are referred to as active components, the molar ratio of nickel to iron sources is 3-5:1, and the mass ratio of the pretreated molecular sieve, active components, additive, and binder is 45-65:25-40:5-10:3-6. The mixing temperature is 50-60℃, the mixing time is 6-10 hours, and the particle size of the spherical particles is 100-200 μm.

[0014] Preferably, in step b, the drying temperature is 100~110℃, the drying time is 6~8h, the calcination temperature is 400~500℃, the calcination time is 3~4h, the reduction atmosphere is a hydrogen-nitrogen mixture, the volume ratio of hydrogen to nitrogen is 10~20:80~90, the reduction temperature is 300~350℃, and the reduction time is 2~3h.

[0015] Preferably, in step 1), the adsorption temperature is 25~50℃, the adsorption pressure is 0.5~1.5MPa, and the space velocity of the mixed gas is 500~1000h. -1 ; In step 3), the desorption treatment temperature is 80~120℃ and the desorption treatment pressure is 0.05~0.1MPa.

[0016] Preferably, in step 2), the adsorption temperature is 30~60℃, the adsorption pressure is 0.3~1MPa, and the space velocity of the exhaust gas discharged from the first adsorption tower is 800~1500h⁻¹. -1 ; In step 4), the desorption treatment temperature is 150~200℃. When the temperature reaches the desorption treatment temperature, nitrogen gas is introduced for purging, and the nitrogen space velocity is 300~500 h⁻¹. -1 .

[0017] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a two-stage adsorption-desorption cycle process. The first adsorption tower selectively adsorbs H2, and the second adsorption tower selectively adsorbs CO, which enables efficient separation and recovery of H2 and CO. The remaining CO2 can be centrally processed later, improving the utilization rate of syngas and eliminating secondary pollution.

[0018] This invention allows for precise control of the H2 and CO yields obtained from desorption by separately controlling the desorption conditions of the first and second adsorption towers. This enables flexible and precise control of the H2 / CO ratio in the syngas, meeting the needs of various chemical reactions.

[0019] The process of this invention is carried out continuously through an adsorption-desorption cycle, and the adsorption tower can quickly return to the adsorption conditions after desorption to enter the next cycle, thus achieving continuous and stable operation and improving production efficiency.

[0020] The first adsorbent of this invention uses modified activated carbon as a carrier, loaded with palladium, copper active components and CeO2 auxiliary agent, and is prepared by a specific process, exhibiting excellent selective adsorption performance for H2; the second adsorbent uses pretreated ZSM-5 molecular sieve as a carrier, loaded with nickel, iron active components and ZrO2 auxiliary agent, and exhibits good selective adsorption performance for CO. The two adsorbents work synergistically to further improve the separation effect and the purity of H2 and CO.

[0021] The adsorbent preparation process of this invention is simple and low in cost, and the adsorption-desorption process operates under mild conditions with low energy consumption, showing good prospects for industrial application. Detailed Implementation

[0022] This invention provides a process for continuous control of the H2 / CO ratio in syngas, the process comprising the following steps: 1) The mixed gas is introduced into the first adsorption tower, where the first adsorbent selectively adsorbs H2, while CO2 and CO are discharged from the first adsorption tower as tail gas. 2) The exhaust gas discharged from the first adsorption tower is passed into the second adsorption tower. The second adsorbent selectively adsorbs CO, and the remaining CO2 is treated as exhaust gas for further processing. 3) The first adsorption tower is desorbed to obtain H2; 4) The second adsorption tower is desorbed to obtain CO; 5) After desorption is completed, the first adsorption tower and the second adsorption tower are restored to their respective adsorption conditions and enter the next adsorption-desorption cycle; The first adsorbent is filled in the first adsorption tower, and the second adsorbent is filled in the second adsorption tower.

[0023] In this invention, the mixed gas preferably includes H2, CO and CO2.

[0024] In this invention, the preparation method of the first adsorbent includes the following steps: A. Activated carbon is placed in nitric acid solution and subjected to reflux and drying in sequence to obtain modified activated carbon; B. After mixing palladium source, copper source, modified activated carbon, additives and water, a binder is added to obtain strip-shaped particles; C. The strip-shaped particles are sequentially dried, calcined, and reduced to obtain the first adsorbent.

[0025] In this invention, in step A, the concentration of the nitric acid solution is preferably 5-10 wt%, more preferably 6-9 wt%, and even more preferably 7-8 wt%. The reflux treatment temperature is preferably 80-90°C, more preferably 82-88°C, and even more preferably 84-86°C. The reflux treatment time is preferably 2-4 h, more preferably 2.5-3.5 h, and even more preferably 3 h. The drying temperature is preferably 110-120°C, more preferably 112-118°C, and even more preferably 114-116°C. The drying time is preferably 8-12 h, more preferably 9-11 h, and even more preferably 10-10.5 h. In step B, the palladium source is preferably PdCl2, the copper source is preferably Cu(NO3)2·3H2O, the auxiliary agent is preferably CeO2, and the binder is preferably aluminum sol. The palladium source and copper source are referred to as active components. The molar ratio of the palladium source and copper source is preferably 1:2~4, more preferably 1:2.5~3.5, and even more preferably 1:3~3.2. The mass ratio of modified activated carbon, active components, auxiliary agent and binder is preferably 50~70:20~35:3~8:2~5, more preferably 55~65:23~32:4~7:3~4, and even more preferably 58~60:26~30:5~6:3~4. The mixing preferably includes ultrasonic mixing and stirring mixing. The ultrasonic mixing time is preferably 30~60 min, more preferably 35~55 min, and even more preferably 40~50 min. The stirring mixing temperature is 60~80℃, and the stirring mixing time is 8~12 h. The diameter of the strip-shaped particles is 2~4 mm.

[0026] In this invention, in step C, the drying temperature is preferably 110-120℃, more preferably 112-118℃, and even more preferably 114-116℃; the drying time is preferably 4-6h, more preferably 4.5-5.5h, and even more preferably 5h; the calcination is preferably carried out under an inert atmosphere; the calcination temperature is preferably 350-450℃, more preferably 360-420℃, and even more preferably 380-400℃; the calcination time is preferably 2-3h, and even more preferably 2.5h; the reduction is preferably carried out under a hydrogen atmosphere; the reduction temperature is preferably 200-250℃, more preferably 210-240℃, and even more preferably 220-230℃; the reduction time is preferably 1-2h, and even more preferably 1.5h.

[0027] Preferably, the preparation method of the second adsorbent includes the following steps: a. After mixing the pretreated molecular sieve, nickel source, iron source, additives and ethanol aqueous solution, a binder is added to obtain spherical particles; b. The spherical particles are sequentially dried, calcined, and reduced to obtain the second adsorbent.

[0028] In this invention, in step a, the pretreatment is preferably a calcination treatment, the calcination temperature is preferably 550~600℃, more preferably 560~590℃, and even more preferably 570~580℃, the calcination time is preferably 2~3h, and even more preferably 2.5h, the molecular sieve is preferably ZSM-5 molecular sieve, the nickel source is preferably Ni(NO3)2·6H2O, the iron source is preferably Fe(NO3)3·9H2O, the auxiliary agent is preferably ZrO2, the binder is preferably silica sol, the volume ratio of ethanol to aqueous solution is preferably 1:1, the nickel source and iron source are referred to as active components, and the molar ratio of nickel source to iron source is preferably 3~5:1, more preferably 3.5~4.5:1, and even more preferably... The mass ratio of the pretreated molecular sieve, active component, additive, and binder is preferably 45-65:25-40:5-10:3-6, more preferably 48-60:28-35:6-9:4-5, and even more preferably 50-55:30-32:7-8:4-5. The mixing temperature is preferably 50-60℃, more preferably 52-58℃, and even more preferably 55-56℃. The mixing time is preferably 6-10h, more preferably 7-9h, and even more preferably 7.5-8h. The particle size of the spherical particles is preferably 100-200μm, more preferably 120-180μm, and even more preferably 140-160μm.

[0029] In this invention, in step b, the drying temperature is preferably 100-110℃, more preferably 102-108℃, and even more preferably 105-106℃; the drying time is preferably 6-8h, more preferably 6.5-7.5h, and even more preferably 7h; the calcination temperature is preferably 400-500℃, more preferably 420-480h, and even more preferably 450-460h; the calcination time is preferably 3-4h, and even more preferably 3.5h; the reducing atmosphere is preferably a hydrogen-nitrogen mixture, with a hydrogen to nitrogen volume ratio preferably 10-20:80-90, more preferably 12-18:82-88, and even more preferably 14-16:84-86; the reduction temperature is preferably 300-350℃, more preferably 310-340℃, and even more preferably 320-330℃; and the reduction time is preferably 2-3h, and even more preferably 2.5h.

[0030] In this invention, in step 1), the adsorption temperature is preferably 25-50°C, more preferably 30-45°C, and even more preferably 35-40°C; the adsorption pressure is preferably 0.5-1.5 MPa, more preferably 0.8-1.4 MPa, and even more preferably 1-1.2 MPa; and the space velocity of the mixed gas is preferably 500-1000 h⁻¹. -1 Further preferably 600~900h -1 More preferably 700~800h -1 ; In step 3), the desorption treatment temperature is preferably 80~120℃, more preferably 90~110℃, and even more preferably 100~105℃, and the desorption treatment pressure is preferably 0.05~0.1MPa, more preferably 0.06~0.09MPa, and even more preferably 0.07~0.08MPa.

[0031] In this invention, in step 2), the adsorption temperature is preferably 30~60℃, more preferably 35~55℃, and even more preferably 40~50℃; the adsorption pressure is preferably 0.3~1MPa, more preferably 0.5~0.9MPa, and even more preferably 0.6~0.7MPa; and the space velocity of the exhaust gas discharged from the first adsorption tower is preferably 800~1500 h⁻¹. -1 Further preferred is 900~1400h -1 More preferably 1000~1200h -1 ; In step 4), the desorption treatment temperature is preferably 150~200℃, more preferably 160~190℃, and even more preferably 170~180℃. When the temperature reaches the desorption treatment temperature, nitrogen gas is introduced for purging, and the nitrogen space velocity is preferably 300~500 h⁻¹. -1 Further preferred is 350~450h-1 More preferably 380~400h -1 .

[0032] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0033] Example 1

[0034] Preparation of the first adsorbent: The activated carbon was placed in a 7wt% nitric acid solution and refluxed at 85℃ for 3 hours, followed by drying at 115℃ for 10 hours to obtain modified activated carbon. Using PdCl2 as the palladium source and Cu(NO3)2·3H2O as the copper source, with a molar ratio of PdCl2 to Cu(NO3)2·3H2O of 1:3, modified activated carbon, active components (PdCl2+Cu(NO3)2·3H2O), CeO2 and aluminum sol were mixed in a mass ratio of 60:28:5:4, and an appropriate amount of water was added. The mixture was first ultrasonically mixed for 45 min, then stirred at 70℃ for 10 h, and finally made into strip-shaped particles with a diameter of 3 mm. The strip-shaped particles were dried at 115℃ for 5 hours, then calcined at 400℃ for 2.5 hours under a nitrogen atmosphere, and finally reduced at 220℃ for 1.5 hours under a hydrogen atmosphere to obtain the first adsorbent.

[0035] Preparation of the second adsorbent: ZSM-5 molecular sieve was pretreated by calcining at 580℃ for 2.5h; Ni(NO3)2·6H2O was used as the nickel source and Fe(NO3)3·9H2O as the iron source, with a molar ratio of Ni(NO3)2·6H2O to Fe(NO3)3·9H2O of 4:1; the pretreated ZSM-5 molecular sieve, active components (Ni(NO3)2·6H2O+Fe(NO3)3·9H2O), ZrO2 additive and silica sol binder were mixed at a mass ratio of 55:32:7:5, and an ethanol aqueous solution with a volume ratio of 1:1 was added; the mixture was stirred at 55℃ for 8h to prepare spherical particles with a particle size of 150μm; The spherical particles were dried at 105℃ for 7 hours, then calcined at 450℃ for 3.5 hours, and finally reduced at 320℃ for 2.5 hours in a hydrogen-nitrogen mixed gas (volume ratio of hydrogen to nitrogen is 15:85) to obtain the second adsorbent.

[0036] Continuous control process of the H2 / CO ratio in syngas: A mixed gas containing H2, CO, and CO2 is passed into a first adsorption tower filled with a first adsorbent. The adsorption temperature is 35℃, the adsorption pressure is 1.0 MPa, and the gas hourly space velocity (GHSV) is 800 h⁻¹. -1The first adsorbent selectively adsorbs H2, while CO2 and CO are discharged as exhaust gas. The exhaust gas discharged from the first adsorption tower is passed into a second adsorption tower filled with a second adsorbent. The adsorption temperature is 45℃, the adsorption pressure is 0.6MPa, and the exhaust gas space velocity is 1200h. -1 The second adsorbent selectively adsorbs CO, and the remaining CO2 is used as exhaust gas for further treatment. The first adsorption tower was subjected to desorption treatment at a temperature of 100℃ and a pressure of 0.08MPa to obtain H2. The second adsorption tower was subjected to desorption treatment at a temperature of 180°C. When the temperature reached 180°C, the space velocity was 400 h⁻¹. -1 Nitrogen gas was used to purge the gas to obtain CO; After desorption is completed, the first adsorption tower is restored to 35℃ and 1.0MPa, and the second adsorption tower is restored to 45℃ and 0.6MPa, and the next adsorption-desorption cycle begins.

[0037] Example 2

[0038] Preparation of the first adsorbent: Activated carbon was placed in a 5 wt% nitric acid solution and refluxed at 80 °C for 4 h, followed by drying at 110 °C for 12 h to obtain modified activated carbon. Using PdCl2 as the palladium source and Cu(NO3)2·3H2O as the copper source, with a molar ratio of PdCl2 to Cu(NO3)2·3H2O of 1:2, modified activated carbon, active components, CeO2 additives, and aluminum sol binder were mixed in a mass ratio of 50:20:3:2, and an appropriate amount of water was added. The mixture was first ultrasonically mixed for 30 min, then stirred and mixed at 60℃ for 12 h, and finally made into strip-shaped particles with a diameter of 2 mm. The strip-shaped particles were dried at 110℃ for 6 hours, then calcined at 350℃ for 3 hours under a nitrogen atmosphere, and finally reduced at 200℃ for 2 hours under a hydrogen atmosphere to obtain the first adsorbent. Preparation of the second adsorbent: ZSM-5 molecular sieve was pretreated by calcining at 550℃ for 3h; Ni(NO3)2·6H2O was used as the nickel source and Fe(NO3)3·9H2O as the iron source, with a molar ratio of Ni(NO3)2·6H2O to Fe(NO3)3·9H2O of 3:1; the pretreated ZSM-5 molecular sieve, active component, ZrO2 additive and silica sol binder were mixed at a mass ratio of 45:25:5:3, and an ethanol aqueous solution with a volume ratio of 1:1 was added; the mixture was mixed at 50℃ for 10h to prepare spherical particles with a particle size of 100μm; The spherical particles were dried at 100℃ for 8 hours, then calcined at 400℃ for 4 hours, and finally reduced at 300℃ for 3 hours in a hydrogen-nitrogen mixed gas (volume ratio of hydrogen to nitrogen is 10:90) to obtain the second adsorbent.

[0039] Continuous control process of the H2 / CO ratio in syngas: A mixed gas containing H2, CO, and CO2 was introduced into the first adsorption tower. The adsorption temperature was 25℃, the adsorption pressure was 0.5MPa, and the gas hourly space velocity (GHSV) was 500 h⁻¹. -1 The first adsorbent selectively adsorbs H2, while CO2 and CO are discharged. The exhaust gas is passed into the second adsorption tower at an adsorption temperature of 30℃, an adsorption pressure of 0.3MPa, and an exhaust gas space velocity of 800h⁻¹. -1 The second adsorbent selectively adsorbs CO, and the remaining CO2 is treated later. The first adsorption tower has a desorption temperature of 80℃ and a desorption pressure of 0.05MPa, yielding H2; The desorption temperature of the second adsorption tower is 150℃, and the space velocity is 300 h⁻¹. -1 Nitrogen gas was used to purge the gas, and CO was obtained. After desorption is completed, the first adsorption tower is restored to 25℃ and 0.5MPa, and the second adsorption tower is restored to 30℃ and 0.3MPa, and then the next cycle begins.

[0040] Example 3

[0041] Preparation of the first adsorbent: Activated carbon was placed in a 10 wt% nitric acid solution and refluxed at 90 °C for 2 h, followed by drying at 120 °C for 8 h to obtain modified activated carbon. Using PdCl2 as the palladium source and Cu(NO3)2·3H2O as the copper source, with a molar ratio of PdCl2 to Cu(NO3)2·3H2O of 1:4, modified activated carbon, active components, CeO2 additives, and aluminum sol binder were mixed in a mass ratio of 70:35:8:5, and an appropriate amount of water was added. The mixture was first ultrasonically mixed for 60 min, then stirred and mixed at 80℃ for 8 h, and finally made into strip-shaped particles with a diameter of 4 mm. The strip-shaped particles were dried at 120°C for 4 hours, then calcined at 450°C for 2 hours under a nitrogen atmosphere, and finally reduced at 250°C for 1 hour under a hydrogen atmosphere to obtain the first adsorbent. Preparation of the second adsorbent: ZSM-5 molecular sieve was pretreated by calcining at 600℃ for 2 hours; Ni(NO3)2·6H2O was used as the nickel source and Fe(NO3)3·9H2O as the iron source, with a molar ratio of Ni(NO3)2·6H2O to Fe(NO3)3·9H2O of 5:1; the pretreated ZSM-5 molecular sieve, active component, ZrO2 additive and silica sol binder were mixed at a mass ratio of 65:40:10:6, and an ethanol aqueous solution with a volume ratio of 1:1 was added; the mixture was mixed at 60℃ for 6 hours to prepare spherical particles with a particle size of 200 μm; The spherical particles were dried at 110℃ for 6 hours, then calcined at 500℃ for 3 hours, and finally reduced at 350℃ for 2 hours in a hydrogen-nitrogen mixed gas (volume ratio of hydrogen to nitrogen is 20:80) to obtain the second adsorbent. Continuous control process of the H2 / CO ratio in syngas: A mixed gas containing H2, CO, and CO2 was introduced into the first adsorption tower. The adsorption temperature was 50℃, the adsorption pressure was 1.5MPa, and the gas hourly space velocity (GHSV) was 1000h. -1 The first adsorbent selectively adsorbs H2, while CO2 and CO are discharged. The exhaust gas is passed into the second adsorption tower at an adsorption temperature of 60℃, an adsorption pressure of 1.0 MPa, and an exhaust gas space velocity of 1500 h⁻¹. -1 The second adsorbent selectively adsorbs CO, and the remaining CO2 is treated later. The first adsorption tower has a desorption temperature of 120℃ and a desorption pressure of 0.1MPa, yielding H2; The desorption temperature of the second adsorption tower is 200℃, and the space velocity is 500 h⁻¹. -1 Nitrogen gas was used to purge the gas, and CO was obtained. After desorption is completed, the first adsorption tower is restored to 50℃ and 1.5MPa, and the second adsorption tower is restored to 60℃ and 1.0MPa, and then the next cycle begins.

[0042] Comparative Example 1

[0043] Compared with Example 1, in the preparation of the first adsorbent in this comparative example, the activated carbon was not modified by reflux of nitric acid solution, and the other preparation conditions were the same as in Example 1.

[0044] Comparative Example 2

[0045] Compared with Example 1, in this comparative example, no ZrO2 additive was added during the preparation of the second adsorbent, and the other preparation conditions were the same as in Example 1.

[0046] Performance testing: Purity testing: The purity of H2 and CO obtained by desorption in Examples 1-3 and Comparative Examples 1-2 was tested using gas chromatography. Proportional control precision: The production of H2 and CO is controlled by adjusting the desorption time. The target H2 / CO ratio is set to 2:1, and the deviation between the actual H2 / CO ratio of the produced gas and the target ratio is detected. Continuous operation stability: The system was run continuously for 72 hours, with the purity of H2 and CO measured every 12 hours, and the changes in purity were recorded.

[0047] Table 1 Performance test results of Examples 1-3 and Comparative Examples 1-2

[0048] As shown in Table 1, the purity of H2 obtained from desorption in Examples 1-3 of this invention is all above 98.5%, and the purity of CO is all above 97.9%, achieving efficient separation of H2 and CO with high product purity. The deviation of the H2 / CO ratio is within 2.2% (only 1.5% in Example 1), demonstrating the process's ability to precisely control the H2 / CO ratio. Furthermore, after continuous operation for 72 hours, the changes in H2 and CO purity are all within 0.6%, indicating good stability. In contrast, Comparative Example 1, due to the lack of activated carbon as the first adsorbent... In Comparative Example 2, the H2 purity was only 95.3% and the H2 / CO ratio deviation reached 4.8% without modification. Furthermore, the H2 purity changed significantly after operation. This indicates that activated carbon modification can significantly improve the selective adsorption performance of the first adsorbent for H2, thus ensuring the precision and stability of the control. In Comparative Example 2, because the second adsorbent did not have ZrO2 additive, the CO purity was only 95.6% and the H2 / CO ratio deviation reached 5.2%. Furthermore, the CO purity changed significantly after operation. This indicates that ZrO2 additive can improve the selective adsorption performance of the second adsorbent for CO.

[0049] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A process for continuously controlling the H2 / CO ratio in syngas, characterized in that, The process includes the following steps: 1) The mixed gas is introduced into the first adsorption tower, where the first adsorbent selectively adsorbs H2, while CO2 and CO are discharged from the first adsorption tower as tail gas. 2) The exhaust gas discharged from the first adsorption tower is passed into the second adsorption tower. The second adsorbent selectively adsorbs CO, and the remaining CO2 is treated as exhaust gas for further processing. 3) The first adsorption tower is desorbed to obtain H2; 4) The second adsorption tower is desorbed to obtain CO; 5) After desorption is completed, the first adsorption tower and the second adsorption tower are restored to their respective adsorption conditions and enter the next adsorption-desorption cycle; The first adsorbent is filled in the first adsorption tower, and the second adsorbent is filled in the second adsorption tower.

2. The process for continuous control of the H2 / CO ratio in syngas according to claim 1, characterized in that, The mixture includes H2, CO and CO2.

3. The process for continuous control of the H2 / CO ratio in syngas according to claim 1, characterized in that, The preparation method of the first adsorbent includes the following steps: A. Activated carbon is placed in nitric acid solution and subjected to reflux and drying in sequence to obtain modified activated carbon; B. After mixing palladium source, copper source, modified activated carbon, additives and water, a binder is added to obtain strip-shaped particles; C. The strip-shaped particles are sequentially dried, calcined, and reduced to obtain the first adsorbent.

4. The process for continuous control of the H2 / CO ratio in syngas according to claim 3, characterized in that, In step A, the concentration of the nitric acid solution is 5-10 wt%, the reflux treatment temperature is 80-90℃, the reflux treatment time is 2-4 h, and the drying temperature is 110-120℃, and the drying time is 8-12 h. In step B, the palladium source is PdCl2, the copper source is Cu(NO3)2·3H2O, the additive is CeO2, and the binder is aluminum sol. The palladium and copper sources are referred to as active components, and the molar ratio of the palladium and copper sources is 1:2~4. The mass ratio of modified activated carbon, active components, additives, and binders is 50~70:20~35:3~8:2~5. The mixing includes ultrasonic mixing and stirring mixing. The ultrasonic mixing time is 30~60 min, the stirring mixing temperature is 60~80℃, and the stirring mixing time is 8~12 h. The diameter of the strip-shaped particles is 2~4 mm.

5. The process for continuous control of the H2 / CO ratio in syngas according to claim 3 or 4, characterized in that, In step C, the drying temperature is 110~120℃ and the drying time is 4~6h. The calcination is carried out in an inert atmosphere at a temperature of 350~450℃ for 2~3h. The reduction is carried out in a hydrogen atmosphere at a temperature of 200~250℃ for 1~2h.

6. The process for continuous control of the H2 / CO ratio in syngas according to claim 1, characterized in that, The preparation method of the second adsorbent includes the following steps: a. After mixing the pretreated molecular sieve, nickel source, iron source, additives and ethanol aqueous solution, a binder is added to obtain spherical particles; b. The spherical particles are sequentially dried, calcined, and reduced to obtain the second adsorbent.

7. The process for continuous control of the H2 / CO ratio in syngas according to claim 6, characterized in that, In step a, the pretreatment is a calcination treatment at a temperature of 550-600℃ for 2-3 hours. The molecular sieve is ZSM-5, the nickel source is Ni(NO3)2·6H2O, the iron source is Fe(NO3)3·9H2O, the additive is ZrO2, the binder is silica sol, the volume ratio of ethanol to aqueous solution is 1:1, the nickel and iron sources are referred to as active components, the molar ratio of nickel to iron sources is 3-5:1, and the mass ratio of the pretreated molecular sieve, active components, additives, and binder is 45-65:25-40:5-10:3-6. The mixing temperature is 50-60℃, the mixing time is 6-10 hours, and the particle size of the spherical particles is 100-200 μm.

8. The process for continuous control of the H2 / CO ratio in syngas according to claim 6 or 7, characterized in that, In step b, the drying temperature is 100~110℃, the drying time is 6~8h, the calcination temperature is 400~500℃, the calcination time is 3~4h, the reduction atmosphere is a hydrogen-nitrogen mixture, the volume ratio of hydrogen to nitrogen is 10~20:80~90, the reduction temperature is 300~350℃, and the reduction time is 2~3h.

9. The process for continuous control of the H2 / CO ratio in syngas according to claim 1, characterized in that, In step 1), the adsorption temperature is 25~50℃, the adsorption pressure is 0.5~1.5MPa, and the space velocity of the mixed gas is 500~1000h. -1 ; In step 3), the desorption treatment temperature is 80~120℃ and the desorption treatment pressure is 0.05~0.1MPa.

10. A process for continuous control of the H2 / CO ratio in syngas according to claim 1 or 9, characterized in that, In step 2), the adsorption temperature is 30~60℃, the adsorption pressure is 0.3~1MPa, and the space velocity of the exhaust gas discharged from the first adsorption tower is 800~1500h⁻¹. -1 ; In step 4), the desorption treatment temperature is 150~200℃. When the temperature reaches the desorption treatment temperature, nitrogen gas is introduced for purging, and the nitrogen space velocity is 300~500 h⁻¹. -1 .

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