A zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated processing system and a method of using the same

Abstract

A kind of zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated processing system and its use method belong to refining tail gas technical field.Solve the problem of large fuel consumption, waste gas pollution emission in prior art.Technical points: refining tail gas enters TSA pretreatment tower and is removed, remaining gas enters PSA hydrogen purification tower and is removed, high-purity hydrogen is injected into town hydrogen pipe network, hydrogen purge gas flows into heat exchanger through shunt pipeline and is injected into PSA hydrogen purification tower, regeneration gas of PSA hydrogen purification tower is injected into TSA pretreatment tower after heating by combustion heater, regeneration gas of TSA pretreatment tower enters combustion heater after heat exchange;The combustion tail gas generated enters VSA separation tower, obtains N2 and CO2.The present application realizes H2 purification and CO2 capture by "adsorption-regeneration gas combustion and heat recovery-heat cascade utilization", obtains high-purity product, achieves resource recovery and harmful gas zero emission.

Description

Technical Field

[0001] This invention relates to the field of refining and chemical tail gas treatment technology, specifically to a zero-emission integrated refining and chemical tail gas treatment system for carbon dioxide capture and hydrogen purification, and its application method. Background Technology

[0002] Refining tail gases from propane cracking and petroleum brain reforming contain large amounts of hydrogen. Before the development of water electrolysis for green hydrogen technology, purifying the hydrogen in these tail gases is a crucial way to ensure hydrogen supply. Refining tail gases contain 50%-85% hydrogen, along with harmful gases such as carbon dioxide, methane, hydrogen sulfide, light hydrocarbons, and carbon monoxide. All industrial hydrogen applications require the removal of these impurities to 0-10 PPM.

[0003] Existing methods for treating refining and chemical waste gas typically employ direct combustion and adsorption. Direct combustion is effective for treating high-concentration, low-flow-rate organic waste gas, completely converting organic matter into carbon dioxide and water; the process is simple, easy to operate, and stable; and the heat generated during combustion can be recovered. Adsorption is suitable for treating low-concentration, high-volume organic waste gas, showing good adsorption effects on various organic compounds; the adsorbent can be regenerated and reused, reducing treatment costs; the equipment is simple, easy to operate, and has low operating and maintenance costs.

[0004] Meanwhile, both direct combustion and adsorption methods have many limitations. Direct combustion requires a large amount of fuel for low-concentration waste gas, resulting in high operating costs. When the waste gas contains elements such as sulfur and chlorine, combustion produces secondary pollutants such as sulfur dioxide and hydrogen chloride, requiring subsequent treatment facilities. The combustion process may also generate nitrogen oxides, increasing nitrogen oxide emissions in the exhaust gas. Adsorption methods have limited adsorption capacity of the adsorbent, requiring regular replacement or regeneration. Regeneration generates wastewater and waste gas pollutants. Adsorption is also sensitive to humidity and temperature; high humidity or temperature negatively impacts adsorption efficiency. Furthermore, the presence of large organic molecules or viscous substances in the waste gas can clog the adsorbent, reducing adsorption efficiency.

[0005] Therefore, there is an urgent need to propose a zero-emission integrated treatment system for carbon dioxide capture, hydrogen purification, and refining tail gas, as well as its application method, to solve the problems of high fuel consumption and waste gas pollution emissions in existing technologies. Summary of the Invention

[0006] In view of the above facts, in order to solve the problems of high fuel consumption and exhaust gas pollution emissions in the prior art, the present invention designs a zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system and its usage method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] Option 1: A zero-emission integrated treatment system for carbon dioxide capture, hydrogen purification, and refining tail gas, comprising a first booster, a second booster, a first compressor, a second compressor, a TSA pretreatment tower, a PSA hydrogen purification tower, a VSA separation tower, a heat exchanger, a combustion heater, a vacuum pump, a gas flow meter, a mass flow controller, a nitrogen storage cylinder, a carbon dioxide storage cylinder, and a town hydrogen pipeline network;

[0009] The air intake pipe is connected in sequence to the first booster, the TSA pretreatment tower, the PSA hydrogen purification tower, the gas flow meter, and the town hydrogen pipeline network.

[0010] The gas generated by the PSA hydrogen purification tower is diverted to the diversion pipeline. One side is connected between the PSA hydrogen purification tower and the gas flow meter, and the other side is connected to the heat exchanger. A mass flow controller is installed on the diversion pipeline.

[0011] The hot fluid outlet of the heat exchanger is connected to a hot hydrogen purging pipeline, and the hot hydrogen purging pipeline is connected to the purging gas end of the PSA hydrogen purification tower.

[0012] The regeneration gas end of the TSA pretreatment tower is connected to a heat exchanger, which is connected to a combustion heater. The regeneration gas end of the PSA hydrogen purification tower is also connected to a combustion heater.

[0013] The hot fluid outlet of the combustion heater is connected to a high-temperature air purging pipe, which is connected to the purging gas end of the TSA pretreatment tower.

[0014] The combustion heater is connected in sequence to the second booster and the VSA separation tower. The purified gas end of the VSA separation tower is connected in sequence to the first compressor and the nitrogen storage cylinder. The regeneration gas end of the VSA separation tower is connected in sequence to the vacuum pump, the second compressor, and the carbon dioxide storage cylinder.

[0015] Furthermore: the exhaust fan is connected to the combustion heater.

[0016] Furthermore: a first gas control valve is installed between the first booster compressor and the TSA pretreatment tower; a second gas control valve is installed on the high-temperature air purging pipeline; a third gas control valve is installed between the TSA pretreatment tower and the PSA hydrogen purification tower; a fourth gas control valve is installed on the hot hydrogen purging gas pipeline; a fifth gas control valve is installed between the PSA hydrogen purification tower and the connection point of the diversion pipeline; a TSA tower regeneration gas outlet back pressure valve is installed between the TSA pretreatment tower and the heat exchanger; a PSA tower regeneration gas outlet back pressure valve is installed between the PSA hydrogen purification tower and the combustion heater; a diversion valve is installed between the connection point of the diversion pipeline and the mass flow controller; an eighth gas control valve is installed between the second booster compressor and the VSA separation tower; a ninth gas control valve is installed between the VSA separation tower and the first compressor; a tenth gas control valve is installed between the vacuum pump and the second compressor; and a pressure regulating valve is installed between the connection point of the diversion pipeline and the gas flow meter.

[0017] Option 2: The method of using the zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system described in Option 1 is as follows:

[0018] Step 1: Refining tail gas enters the TSA pretreatment tower through the intake pipe to remove H2S, light hydrocarbons, and CO;

[0019] Step 2: The remaining gas enters the PSA hydrogen purification tower to remove CO2 and CH4. The high-purity hydrogen is injected into the town's hydrogen pipeline network, and the hydrogen purge gas flows into the heat exchanger through the diversion pipe.

[0020] Step 3: The heat exchanger injects 10% hydrogen as hot hydrogen purge gas into the PSA hydrogen purification tower, and the regeneration gas of the PSA hydrogen purification tower enters the combustion heater.

[0021] Step 4: The combustion heater injects 150°C high-temperature air purge gas into the TSA pretreatment tower. The regeneration gas from the TSA pretreatment tower enters the combustion heater after heat exchange through a heat exchanger.

[0022] Step 5: The combustion exhaust gas generated by the combustion heater enters the VSA separation tower to obtain N2 and CO2.

[0023] Further: in step one, H2S is removed to ≤0.004ppm, light hydrocarbons to ≤2ppm, and CO to ≤0.2ppm.

[0024] Further: In step one, the TSA pretreatment tower is filled with three layers of adsorbent: the bottom layer is a Y-type molecular sieve to remove H2S, the middle layer is activated carbon to remove light hydrocarbons, and the top layer is an A-type molecular sieve to remove CO.

[0025] In step two, the PSA hydrogen purification tower is filled with two layers of adsorbent. The bottom layer is set with 13X and its modified molecular sieve to remove CO2, and the top layer is set with carbon molecular sieve to remove CH4.

[0026] In step five, the VSA separation tower is filled with 13X molecular sieves and their modified molecular sieves to selectively adsorb CO2.

[0027] Further: In step two, CO2 is removed to ≤2ppm and CH4 to ≤2ppm.

[0028] Furthermore, in step five, the pressure of the combustion exhaust gas is 0.1 MPa, which is then boosted to 1.5 MPa by the second booster.

[0029] Furthermore, the vacuum level of the vacuum pump in step five is 100 kPa.

[0030] The beneficial effects of this invention are as follows:

[0031] 1. This invention achieves H2 purification and CO2 capture through "adsorption-regenerated gas combustion and heat recovery-heat cascade utilization", obtains high-purity products, optimizes the overall process flow, improves the stability and reliability of the system, and achieves resource recovery and zero emission of harmful gases.

[0032] 2. This invention reduces greenhouse gas emissions, mitigates atmospheric pollution, and improves surrounding air quality.

[0033] 3. This invention enables the recycling of resources, reduces production costs, and creates additional economic benefits.

[0034] 4. This invention can reduce the demand for external energy in production, reduce energy consumption and production costs, improve energy utilization efficiency, and achieve the goal of energy conservation and emission reduction. Attached Figure Description

[0035] Figure 1 This is a system flowchart of the present invention.

[0036] In the diagram: 1-First booster compressor, 2-Second booster compressor, 3-First compressor, 4-Second compressor, 5-TSA pretreatment tower, 6-PSA hydrogen purification tower, 7-VSA separation tower, 8-Heat exchanger, 9-Combustion heater, 10-Exhaust fan, 11-Vacuum pump, 12-Gas flow meter, 13-Mass flow controller, 14-Nitrogen storage cylinder, 15-Carbon dioxide storage cylinder, 16-Urban hydrogen pipeline network, 17-First gas control valve, 18-Second gas control valve, 19-Third gas control valve, 20-Fourth gas control valve, 21-Fifth gas control valve, 22-TSA tower regenerated gas outlet back pressure valve, 23-PSA tower regenerated gas outlet back pressure valve, 24-Diverter valve, 25-Eighth gas control valve, 26-Ninth gas control valve, 27-Tenth gas control valve, 28-Pressure regulating valve. Detailed Implementation

[0037] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present application.

[0038] The terms "set up," "connect," and "fix" should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0039] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0041] Example 1: This example describes a zero-emission integrated treatment system for carbon dioxide capture, hydrogen purification, and refining tail gas, comprising a first booster 1, a second booster 2, a first compressor 3, a second compressor 4, a TSA pretreatment tower 5, a PSA hydrogen purification tower 6, a VSA separation tower 7, a heat exchanger 8, a combustion heater 9, a vacuum pump 11, a gas flow meter 12, a mass flow controller 13, a nitrogen storage cylinder 14, a carbon dioxide storage cylinder 15, and a town hydrogen pipeline network 16.

[0042] The air intake pipe is sequentially connected to the first booster 1, TSA pretreatment tower 5, PSA hydrogen purification tower 6, gas flow meter 12, and urban hydrogen pipeline network 16.

[0043] The generated gas from the PSA hydrogen purification tower 6 is diverted to a diversion pipe. One side is connected between the PSA hydrogen purification tower 6 and the gas flow meter 12, and the other side is connected to the heat exchanger 8. A mass flow controller 13 is installed on the diversion pipe.

[0044] The hot fluid outlet end of the heat exchanger 8 is connected to the hot hydrogen purging pipeline, and the hot hydrogen purging gas pipeline is connected to the purging gas end of the PSA hydrogen purification tower 6.

[0045] The regeneration gas end of the TSA pretreatment tower 5 is connected to the heat exchanger 8, and the heat exchanger 8 is connected to the combustion heater 9. The regeneration gas end of the PSA hydrogen purification tower 6 is also connected to the combustion heater 9.

[0046] The hot fluid outlet end of the combustion heater 9 is connected to a high-temperature air purging pipe, which is connected to the purging gas end of the TSA pretreatment tower 5.

[0047] The combustion heater 9 is connected in sequence to the second booster 2 and the VSA separation tower 7. The purified gas end of the VSA separation tower 7 is connected in sequence to the first compressor 3 and the nitrogen storage cylinder 14. The regeneration gas end of the VSA separation tower 7 is connected in sequence to the vacuum pump 11, the second compressor 4, and the carbon dioxide storage cylinder 15.

[0048] More specifically: the exhaust fan 10 is connected to the combustion heater 9.

[0049] More specifically: a first gas control valve 17 is installed between the first booster 1 and the TSA pretreatment tower 5; a second gas control valve 18 is installed on the high-temperature air purging pipeline; a third gas control valve 19 is installed between the TSA pretreatment tower 5 and the PSA hydrogen purification tower 6; a fourth gas control valve 20 is installed on the hot hydrogen purging gas pipeline; a fifth gas control valve 21 is installed between the PSA hydrogen purification tower 6 and the connection point of the diversion pipeline; and a TSA tower regeneration gas outlet back pressure valve is installed between the TSA pretreatment tower 5 and the heat exchanger 8. 22. A PSA tower regeneration gas outlet back pressure valve 23 is installed between the PSA hydrogen purification tower 6 and the combustion heater 9. A diversion valve 24 is installed between the diversion pipeline connection point and the mass flow controller 13. An eighth gas control valve 25 is installed between the second booster 2 and the VSA separation tower 7. A ninth gas control valve 26 is installed between the VSA separation tower 7 and the first compressor 3. A tenth gas control valve 27 is installed between the vacuum pump 11 and the second compressor 4. A pressure regulating valve 28 is installed between the diversion pipeline connection point and the gas flow meter 12.

[0050] Example 2: The method of using the zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system described in Example 1 is as follows:

[0051] Step 1: Refining tail gas enters TSA pretreatment tower 5 through the inlet pipe to remove H2S, light hydrocarbons, and CO;

[0052] Step 2: The remaining gas enters the PSA hydrogen purification tower 6 to remove CO2 and CH4. High-purity hydrogen is injected into the town's hydrogen pipeline network 16, and the hydrogen purge gas flows into the heat exchanger 8 through the diversion pipe.

[0053] Step 3: Heat exchanger 8 injects 10% hydrogen as hot hydrogen purge gas into PSA hydrogen purification tower 6, and the regeneration gas of PSA hydrogen purification tower 6 enters combustion heater 9.

[0054] Step 4: The combustion heater 9 injects 150°C high-temperature air purge gas into the TSA pretreatment tower 5. The regeneration gas of the TSA pretreatment tower 5 enters the combustion heater 9 after heat exchange through the heat exchanger 8.

[0055] Step 5: The combustion exhaust gas generated by the combustion heater 9 enters the VSA separation tower 7 to obtain N2 and CO2.

[0056] More specifically: in step one, H2S is removed to ≤0.004ppm, light hydrocarbons (calculated as methane) to ≤2ppm, and CO to ≤0.2ppm.

[0057] More specifically: In step one, the TSA pretreatment tower 5 is filled with three layers of adsorbent, with a Y-type molecular sieve at the bottom to remove H2S, activated carbon in the middle to remove light hydrocarbons, and an A-type molecular sieve at the top to remove CO.

[0058] More specifically: in step two, CO2 is removed to ≤2ppm and CH4 to ≤2ppm.

[0059] More specifically: In step two, the PSA hydrogen purification tower 6 is filled with two layers of adsorbent, with 13X and its modified molecular sieves at the bottom to remove CO2, and carbon molecular sieves (pore size 0.3-0.5nm) at the top to remove CH4.

[0060] More specifically: in step five, the pressure of the combustion exhaust gas is 0.1 MPa, which is then boosted to 1.5 MPa by the second booster 2.

[0061] More specifically: In step five, N2 is collected as purified gas and used as a product (purity > 99.99%), and CO2 is collected as regenerated gas and used as a product (purity > 99%).

[0062] More specifically: the vacuum degree of vacuum pump 11 in step five is 100 kPa.

[0063] More specifically: in step five, the VSA separation tower 7 is filled with 13X molecular sieve and its modified molecular sieve to selectively adsorb CO2.

[0064] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; as long as there is no structural conflict, the various features in the specific embodiments disclosed in this application can be combined with each other in any way, and will not cause the substance of the corresponding technical solutions to deviate from the scope of the technical solutions of the present invention.

[0065] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A zero-emission integrated system for carbon dioxide capture, hydrogen purification, and refining tail gas treatment, characterized in that, Includes a first booster (1), a second booster (2), a first compressor (3), a second compressor (4), a TSA pretreatment tower (5), a PSA hydrogen purification tower (6), a VSA separation tower (7), a heat exchanger (8), a combustion heater (9), a vacuum pump (11), a gas flow meter (12), a mass flow controller (13), a nitrogen storage cylinder (14), a carbon dioxide storage cylinder (15), and a town hydrogen pipeline network (16); The air intake pipe is connected in sequence to the first booster (1), TSA pretreatment tower (5), PSA hydrogen purification tower (6), gas flow meter (12), and town hydrogen pipeline (16). The PSA hydrogen purification tower (6) generates gas which is diverted to a diversion pipe. One side of the connection point is between the PSA hydrogen purification tower (6) and the gas flow meter (12), and the other side is connected to the heat exchanger (8). A mass flow controller (13) is installed on the diversion pipe. The hot fluid outlet end of the heat exchanger (8) is connected to the hot hydrogen purging pipeline, and the hot hydrogen purging pipeline is connected to the purging gas end of the PSA hydrogen purification tower (6). The regeneration gas end of the TSA pretreatment tower (5) is connected to a heat exchanger (8), the heat exchanger (8) is connected to a combustion heater (9), and the regeneration gas end of the PSA hydrogen purification tower (6) is connected to a combustion heater (9). The hot fluid outlet end of the combustion heater (9) is connected to a high-temperature air purging pipe, which is connected to the purging gas end of the TSA pretreatment tower (5). The combustion heater (9) is connected in sequence to the second booster (2) and the VSA separation tower (7). The purified gas end of the VSA separation tower (7) is connected in sequence to the first compressor (3) and the nitrogen storage cylinder (14). The regeneration gas end of the VSA separation tower (7) is connected in sequence to the vacuum pump (11), the second compressor (4), and the carbon dioxide storage cylinder (15).

2. The zero-emission integrated treatment system for carbon dioxide capture, hydrogen purification, and refining tail gas according to claim 1, characterized in that: The exhaust fan (10) is connected to the combustion heater (9).

3. The zero-emission integrated treatment system for carbon dioxide capture, hydrogen purification, and refining tail gas according to claim 1, characterized in that: A first gas control valve (17) is installed between the first booster (1) and the TSA pretreatment tower (5); a second gas control valve (18) is installed on the high-temperature air purging pipeline; a third gas control valve (19) is installed between the TSA pretreatment tower (5) and the PSA hydrogen purification tower (6); a fourth gas control valve (20) is installed on the hot hydrogen purging gas pipeline; a fifth gas control valve (21) is installed between the PSA hydrogen purification tower (6) and the connection point of the diversion pipeline; and a TSA tower regeneration gas outlet back pressure valve (22) is installed between the TSA pretreatment tower (5) and the heat exchanger (8). A PSA tower regeneration gas outlet back pressure valve (23) is installed between the hydrogen purification tower (6) and the combustion heater (9). A diversion valve (24) is installed between the diversion pipeline connection point and the mass flow controller (13). An eighth gas control valve (25) is installed between the second booster (2) and the VSA separation tower (7). A ninth gas control valve (26) is installed between the VSA separation tower (7) and the first compressor (3). A tenth gas control valve (27) is installed between the vacuum pump (11) and the second compressor (4). A pressure regulating valve (28) is installed between the diversion pipeline connection point and the gas flow meter (12).

4. The method of using the zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system as described in claim 1, characterized in that: Specifically: Step 1: The refining tail gas enters the TSA pretreatment tower (5) through the intake pipe to remove H2S, light hydrocarbons, and CO; Step 2: The remaining gas enters the PSA hydrogen purification tower (6) to remove CO2 and CH4. High-purity hydrogen is injected into the town's hydrogen pipeline network (16), and the hydrogen purge gas flows into the heat exchanger (8) through the diversion pipe. Step 3: The heat exchanger (8) injects 10% hydrogen as hot hydrogen purge gas into the PSA hydrogen purification tower (6), and the regeneration gas of the PSA hydrogen purification tower (6) enters the combustion heater (9). Step 4: The combustion heater (9) injects 150°C high-temperature air purge gas into the TSA pretreatment tower (5), and the regeneration gas of the TSA pretreatment tower (5) enters the combustion heater (9) after heat exchange through the heat exchanger (8). Step 5: The combustion exhaust gas generated by the combustion heater (9) enters the VSA separation tower (7) to obtain N2 and CO2.

5. The method of using the zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system according to claim 4, characterized in that: In step one, H2S is removed to ≤0.004ppm, light hydrocarbons to ≤2ppm, and CO to ≤0.2ppm.

6. The method of using the zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system according to claim 4, characterized in that: In step one, the TSA pretreatment tower (5) is filled with three layers of adsorbent: the bottom layer is set with Y-type molecular sieve to remove H2S, the middle layer is set with activated carbon to remove light hydrocarbons, and the top layer is set with A-type molecular sieve to remove CO. In step two, the PSA hydrogen purification tower (6) is filled with two layers of adsorbent. The bottom layer is set with 13X and its modified molecular sieve to remove CO2, and the top layer is set with carbon molecular sieve to remove CH4. In step five, the VSA separation tower (7) is filled with 13X molecular sieve and its modified molecular sieve to selectively adsorb CO2.

7. The method of using the zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system according to claim 4, characterized in that: In step two, CO2 is removed to ≤2ppm and CH4 to ≤2ppm.

8. The method of using the zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system according to claim 4, characterized in that: In step five, the pressure of the combustion exhaust gas is 0.1 MPa, which is then increased to 1.5 MPa by the second booster (2).

9. The method of using the zero-emission carbon dioxide capture-hydrogen purification refining tail gas integrated treatment system according to claim 4, characterized in that: The vacuum degree of the vacuum pump (11) in step five is 100 kPa.

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