Tail gas desulfurization coupling carbon capture system and process

Abstract

The invention discloses a tail gas desulfurization coupling carbon capture system and process, and belongs to the technical field of chemical engineering. The invention discloses a tail gas desulfurization coupling carbon capture system which comprises an online combustion furnace, a hydrogenation reactor, a cooling mechanism, a tail gas absorption tower, a tail gas regeneration tower, a carbon capture absorption tower and a carbon capture regeneration tower which are sequentially connected, and the online combustion furnace is connected with a Claus tail gas conveying pipe, a fuel gas conveying pipe and an air conveying pipe; the tail gas absorption tower is connected with a tail gas output pipe; the carbon capture absorption tower is connected with a CO2 gas output pipe; and the carbon capture regeneration tower is connected with an H2S-rich acid gas output pipe. The invention discloses a tail gas desulfurization coupling carbon capture process adopting the system. According to the invention, the Claus sulfur recovery tail gas can be subjected to desulfurization and carbon capture, the amount of tail gas entering the carbon capture unit is greatly reduced, one-time investment and operation energy consumption are saved, and the tail gas can be discharged up to the standard.

Description

Technical Field

[0001] This invention belongs to the field of chemical technology, specifically relating to a tail gas desulfurization coupled carbon capture system and process. Background Technology

[0002] The main sources of CO2 emissions in the natural gas industry include those generated during the processes of water-jacketed boilers, gas-fired boilers, regenerator heaters, flare combustion, natural gas decarbonization, and sulfur recovery units in oil and gas extraction, processing, storage, and transportation. Among these, flue gas from gas-fired boilers and tail gas from sulfur recovery units are the primary sources of CO2 emissions. The characteristics of the carbon source in the flue gas from gas-fired boilers are low pressure, oxygen content, and trace amounts of NO. X While the SO2 and CO2 concentrations are relatively low (around 10%), the carbon source of Claus emissions is characterized by low pressure, lack of oxygen, moderate CO2 concentration (20-40%), and the presence of H2S, SO2, and sulfur vapor.

[0003] Generally, carbon capture can be performed directly on flue gas, with common methods including chemical absorption and pressure swing adsorption. Although chemical methods are widely used, they still suffer from problems such as high energy consumption for CO2 capture, easy oxidation and degradation of the absorbent solution, and high CO2 capture costs, which to some extent limit the widespread industrial application of flue gas carbon capture.

[0004] Carbon capture of the tail gas from a Claus sulfur recovery unit requires prior treatment. This includes not only capturing CO2 but also desulfurizing the tail gas to ensure that the final emissions meet national environmental standards. The main methods employed are as follows:

[0005] One method involves first reducing SO2 and sulfur vapor in the Claus tail gas to H2S via hydrogenation, then selectively absorbing H2S from the tail gas using an alkanolamine liquid absorption unit. The absorbed tail gas is then subjected to a carbon capture process using chemical absorption or pressure swing adsorption to complete both desulfurization and carbon capture. This method requires a large volume of gas, high investment in equipment, and high operating costs.

[0006] Another method involves first oxidizing H2S and sulfur vapors in the Claus tail gas into SO2 through high-temperature incineration. Then, a patented solvent (such as the absorbent for cyclically absorbing sulfur dioxide in natural gas tail gas, as described in patent publication number CN 107019996 A) is used to selectively absorb the SO2 in the tail gas. The absorbed tail gas then undergoes a carbon capture process using chemical absorption or pressure swing adsorption to complete both desulfurization and carbon capture. This method requires a specially developed solvent system, and the solvent is easily degraded in an aerobic environment, resulting in high equipment investment and operating costs.

[0007] Therefore, providing a tail gas desulfurization coupled carbon capture process that can desulfurize and capture carbon in Claus sulfur recovery tail gas, greatly reducing the amount of tail gas entering the carbon capture unit, saving one-time investment and operating energy consumption, and achieving tail gas emission standards has become an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0008] One of the objectives of this invention is to provide a tail gas desulfurization coupled carbon capture system. Using this system to desulfurize and capture carbon in Claus sulfur recovery tail gas can save on initial investment and operating energy consumption, and achieve tail gas emission standards.

[0009] The second objective of this invention is to provide a tail gas desulfurization coupled carbon capture process using the above-mentioned system.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] The present invention discloses a tail gas desulfurization coupled carbon capture system, comprising an online combustion furnace, a hydrogenation reactor, a cooling mechanism, a tail gas absorption tower, a tail gas regeneration tower, a carbon capture absorption tower and a carbon capture regeneration tower connected in sequence.

[0012] The furnace of the online combustion furnace is connected to a Claus exhaust gas delivery pipe, and the burner of the online combustion furnace is connected to a fuel gas delivery pipe and an air delivery pipe.

[0013] The hydrogenation reactor is used to reduce SO2 in Claus tail gas to H2S;

[0014] The tail gas absorption tower is used to absorb H2S and CO2 in the tail gas after hydrogenation reaction. The tail gas absorption tower is connected to a tail gas output pipe.

[0015] The tail gas regeneration tower is used to strip a solution rich in H2S and CO2 to regenerate a mixed acid gas rich in H2S and CO2.

[0016] The carbon capture and absorption tower is used to selectively remove H2S from mixed acid gas rich in H2S and CO2. The carbon capture and absorption tower is connected to a CO2 gas output pipe to discharge the high CO2 content gas after the H2S has been removed.

[0017] The carbon capture and regeneration tower is used to strip H2S-containing solutions to regenerate H2S-rich gas. The carbon capture and regeneration tower is connected to an output pipe for H2S-rich acid gas.

[0018] In some embodiments of the present invention, the cooling mechanism includes a waste heat boiler connected to the hydrogenation reactor and a quench tower connected to the waste heat boiler, the top of which is connected to the tail gas absorption tower via a pipeline.

[0019] Preferably, a quench water cooler is connected to the bottom of the quench tower via a pipe, and the outlet of the quench water cooler is connected to the top of the quench tower via a pipe.

[0020] More preferably, a quenching pump is installed on the pipe connecting the bottom of the quenching tower to the quenching water cooler.

[0021] In some embodiments of the present invention, a tail gas incinerator is also included, and a tail gas output pipe is connected to the tail gas incinerator.

[0022] In some embodiments of the present invention, the bottom of the tail gas absorption tower is connected to the tail gas regeneration tower via a tail gas rich liquid conveying pipe, and a tail gas lean-rich liquid heat exchanger is installed on the tail gas rich liquid conveying pipe.

[0023] The bottom of the tail gas regeneration tower is connected to a tail gas reboiler, and the tail gas reboiler is connected to a tail gas lean liquid delivery pipe. The tail gas lean liquid delivery pipe passes through the shell side of the tail gas lean and rich liquid heat exchanger and connects to the upper part of the tail gas absorption tower.

[0024] Preferably, a tail gas lean liquid cooler is installed in the part of the tail gas lean liquid conveying pipe located between the tail gas absorption tower and the tail gas lean and rich liquid heat exchanger.

[0025] Preferably, a rich liquid pump is installed on the tail gas conveying pipe between the tail gas absorption tower and the rich and lean liquid heat exchanger.

[0026] Preferably, a lean exhaust gas pump is installed on the exhaust gas lean liquid delivery pipe between the exhaust gas lean liquid cooler and the exhaust gas lean and rich liquid heat exchanger.

[0027] In some embodiments of the present invention, there are also a tail gas acid gas cooler connected from the top of the tail gas regeneration tower and a tail gas acid gas separator connected from the tail gas acid gas cooler. The liquid outlet of the tail gas acid gas separator is connected to the tail gas regeneration tower via a pipeline, and the gas outlet of the tail gas acid gas separator is connected to the carbon capture and absorption tower via a pipeline.

[0028] Preferably, a tail gas acid water return pump is installed on the pipeline connecting the liquid outlet of the tail gas acid gas separator and the tail gas regeneration tower.

[0029] In some embodiments of the present invention, the bottom is connected to a carbon capture regeneration tower via a carbon capture rich liquid conveying pipe, and a carbon capture lean-rich liquid heat exchanger is installed on the carbon capture rich liquid conveying pipe.

[0030] The bottom of the carbon capture regeneration tower is connected to a carbon capture reboiler, and the carbon capture reboiler is connected to a carbon capture lean liquor delivery pipe. The carbon capture lean liquor delivery pipe passes through the shell side of the carbon capture lean and rich liquor heat exchanger and connects to the upper part of the carbon capture absorption tower.

[0031] Preferably, a carbon capture lean liquor cooler is installed on the carbon capture lean liquor conveying pipe between the carbon capture absorption tower and the carbon capture lean and rich liquor heat exchanger.

[0032] Preferably, a carbon capture rich liquid pump is installed on the carbon capture rich liquid conveying pipe between the carbon capture absorption tower and the carbon capture lean rich liquid heat exchanger.

[0033] Preferably, a carbon capture lean liquor pump is installed on the carbon capture lean liquor delivery pipe between the carbon capture lean liquor cooler and the carbon capture lean and rich liquor heat exchanger.

[0034] In some embodiments of the present invention, the exhaust gas desulfurization coupled carbon capture system further includes a carbon capture cooler and a carbon capture acid gas separator connected to the carbon capture cooler; an H2S-rich acid gas output pipe is connected to the carbon capture cooler.

[0035] The liquid outlet of the carbon capture acid gas separator is connected to the carbon capture regeneration tower via a pipeline, and the gas outlet of the carbon capture acid gas separator is connected to the sulfur recovery unit via a pipeline.

[0036] Preferably, a carbon capture acid water reflux pump is installed on the pipeline connecting the liquid outlet of the carbon capture acid gas separator and the carbon capture regeneration tower.

[0037] The present invention discloses a tail gas desulfurization coupled carbon capture process, which uses the above-mentioned system.

[0038] In some embodiments of the present invention, the exhaust gas desulfurization coupled carbon capture process includes the following steps:

[0039] Step 1: Air, fuel gas, and air-Claus tail gas are fed into the online combustion furnace. The air and fuel gas undergo subequivalent combustion in the online combustion furnace to produce H2 and CO, while simultaneously heating the Claus tail gas. The combusted gas and the heated Claus tail gas exit the online combustion furnace, forming a high-temperature mixed gas.

[0040] Step 2: The high-temperature mixed gas from the online combustion furnace enters the hydrogenation reactor, where SO2 in the mixed gas is reduced to H2S under the action of a catalyst.

[0041] Step 3: The mixed gas exiting the hydrogenation reactor is cooled by a cooling mechanism and then enters the tail gas absorption tower;

[0042] Step 4: The mixed gas entering the tail gas absorption tower is absorbed by the solution and then discharged from the top of the tower; the solution rich in H2S and CO2 at the bottom of the tail gas absorption tower enters the tail gas regeneration tower.

[0043] Step 5: The solution rich in H2S and CO2 is stripped by steam in the tail gas regeneration tower, and the mixed gas rich in H2S and CO2 is discharged from the tail gas regeneration tower and enters the carbon capture and absorption tower.

[0044] Step 6: The mixed gas rich in H2S and CO2 that enters the carbon capture and absorption tower undergoes selective removal of H2S through solution absorption, and then the high CO2 gas discharged from the top of the tower, while the H2S-rich solution at the bottom of the carbon capture and absorption tower enters the carbon capture and regeneration tower.

[0045] Step 7: The H2S-rich solution is stripped by steam in the carbon capture and regeneration tower, and the H2S-rich mixed gas is discharged from the top of the carbon capture and regeneration tower and returned to the sulfur recovery unit.

[0046] In some embodiments of the present invention, in step one, the Claus exhaust gas is heated to 260-300°C, preferably 280°C;

[0047] In step three, the mixed gas exiting the hydrogenation reactor is cooled to 30-50°C, preferably 40°C, by a cooling mechanism before entering the tail gas absorption tower.

[0048] In step five, the mixed gas rich in H2S and CO2 is discharged from the tail gas regeneration tower, cooled to 30-50°C by a cooling mechanism, preferably 40°C, and then enters the carbon capture and absorption tower.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] (1) This invention is scientifically designed and ingeniously conceived. This invention creatively removes H2S and CO2 from the tail gas in the tail gas absorption tower. Compared with conventional tail gas desulfurization units that use selective solvents to remove H2S, resulting in a large amount of impurities such as N2 and H2 entering the carbon capture unit from the top of the tail gas absorption tower, this invention uses a total removal solvent to remove H2S and CO2 from the tail gas in the tail gas desulfurization unit. The carbon capture unit only needs to selectively remove H2S from the regenerated acid gas containing H2S and CO2, reducing the amount of tail gas entering the carbon capture unit by about 45%, thus achieving the goal of saving one-time investment.

[0051] (2) In the tail gas desulfurization unit, the present invention uses a fully desulfurized solvent to remove H2S and CO2 throughout the entire process. The desulfurized exhaust gas can achieve SO2 emission in compliance with standards and CO2 near-zero emission.

[0052] (3) The present invention can achieve CO2 capture on the tail gas treatment device of the existing wet desulfurization by replacing the desulfurization solution and adding selective H2S removal and solvent regeneration facilities. Attached Figure Description

[0053] Appendix Figure 1 This is a schematic diagram of the system of the present invention.

[0054] The names corresponding to the reference numerals in the attached figures are as follows:

[0055] 1-Online combustion furnace, 2-Hydrogenation reactor, 3-Waste heat boiler, 4-Quick cooler tower, 5-Quick cooler pump, 6-Quick cooler water cooler, 7-Tail gas absorption tower, 8-Tail gas rich liquid pump, 9-Tail gas lean / rich liquid heat exchanger, 10-Tail gas regeneration tower, 11-Tail gas reboiler, 12-Tail gas lean liquid pump, 13-Tail gas lean liquid cooler, 14-Tail gas acid water reflux pump, 15-Tail gas acid gas cooler 16-Tail gas acid gas separator, 17-Carbon capture absorption tower, 18-Carbon capture rich liquid pump, 19-Carbon capture lean and rich liquid heat exchanger, 20-Carbon capture regeneration tower, 21-Carbon capture reboiler, 22-Carbon capture lean liquid pump, 23-Carbon capture lean liquid cooler, 24-Carbon capture acid gas cooler, 25-Carbon capture acid water reflux pump, 26-Carbon capture acid gas separator, 27-Tail gas incinerator;

[0056] 101-Klaus exhaust gas delivery pipe, 102-Fuel gas delivery pipe, 103-Air delivery pipe, 104-Exhaust gas output pipe, 105-CO2 gas output pipe, 106-H2S-rich acid gas output pipe, 107-Exhaust gas rich liquid delivery pipe, 108-Exhaust gas lean liquid delivery pipe, 109-Carbon capture rich liquid delivery pipe, 110-Carbon capture lean liquid delivery pipe, 111-High temperature mixed gas delivery pipe. Detailed Implementation

[0057] Specific embodiments of the present invention are described to enable those skilled in the art to understand the invention. However, it should be understood that the invention is not limited to the scope of the specific embodiments. For those skilled in the art, various changes are obvious as long as they are within the spirit and scope of the invention as defined and determined by the appended claims. All inventions utilizing the concept of the present invention are protected.

[0058] Unless otherwise specified in the examples, the procedures should be performed under standard conditions or conditions recommended by the manufacturer. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0059] Example 1

[0060] As attached Figure 1 As shown, this embodiment discloses a tail gas desulfurization coupled carbon capture system, including an online combustion furnace 1, a hydrogenation reactor 2, a cooling mechanism, a tail gas absorption tower 7, a tail gas regeneration tower 10, a carbon capture absorption tower 17, and a carbon capture regeneration tower 20 connected in sequence.

[0061] The furnace chamber of the online combustion furnace 1 is connected to a Claus tail gas delivery pipe 101, and the burner of the online combustion furnace 1 is connected to a fuel gas delivery pipe 102 and an air delivery pipe 103; a high-temperature mixed gas delivery pipe 111 is connected between the online combustion furnace 1 and the hydrogenation reactor 2, which is used to send the combustion gas and the heated Claus tail gas into the hydrogenation reactor 2.

[0062] The hydrogenation reactor 2 is used to reduce SO2 in Claus tail gas to H2S; the tail gas absorption tower 7 is used to absorb H2S and CO2 in the tail gas after hydrogenation reaction, and the tail gas absorption tower 7 is connected to a tail gas output pipe 104.

[0063] The tail gas regeneration tower 10 is used to strip the solution rich in H2S and CO2 to regenerate a mixed acid gas rich in H2S and CO2.

[0064] The carbon capture and absorption tower 17 is used to selectively remove H2S from the mixed acid gas rich in H2S and CO2. The carbon capture and absorption tower 17 is connected to a CO2 gas output pipe 105, which is used to discharge the high CO2 content gas after the H2S has been removed.

[0065] The carbon capture and regeneration tower 20 is used to strip the H2S-containing solution to regenerate H2S-rich gas, and the carbon capture and regeneration tower 20 is connected to an H2S-rich acid gas output pipe 106.

[0066] Example 2

[0067] As attached Figure 1 As shown, this embodiment discloses a tail gas desulfurization coupled carbon capture system, including an online combustion furnace 1, a hydrogenation reactor 2, a cooling mechanism, a tail gas absorption tower 7, a tail gas regeneration tower 10, a carbon capture absorption tower 17, and a carbon capture regeneration tower 20 connected in sequence.

[0068] The furnace of the online combustion furnace 1 is connected to a Claus exhaust gas delivery pipe 101, and the burner of the online combustion furnace 1 is connected to a fuel gas delivery pipe 102 and an air delivery pipe 103.

[0069] A high-temperature mixed gas delivery pipe 111 is connected between the online combustion furnace 1 and the hydrogenation reactor 2, which is used to send the combustion gas and the heated Claus tail gas into the hydrogenation reactor 2.

[0070] The hydrogenation reactor 2 is used to reduce SO2 in Claus tail gas to H2S; the tail gas absorption tower 7 is used to absorb H2S and CO2 in the tail gas after hydrogenation reaction, and the tail gas absorption tower 7 is connected to a tail gas output pipe 104.

[0071] The tail gas regeneration tower 10 is used to strip the solution rich in H2S and CO2 to regenerate a mixed acid gas rich in H2S and CO2.

[0072] The carbon capture and absorption tower 17 is used to selectively remove H2S from the mixed acid gas rich in H2S and CO2. The carbon capture and absorption tower 17 is connected to a CO2 gas output pipe 105, which is used to discharge the high CO2 content gas after the H2S has been removed.

[0073] The carbon capture and regeneration tower 20 is used to strip the H2S-containing solution to regenerate H2S-rich gas, and the carbon capture and regeneration tower 20 is connected to an H2S-rich acid gas output pipe 106.

[0074] The cooling mechanism includes a waste heat boiler 3 connected to the hydrogenation reactor 2 and a quench tower 4 connected to the waste heat boiler 3. The top of the quench tower 4 is connected to the tail gas absorption tower 7 via a pipeline.

[0075] The bottom of the quench tower 4 is connected to a quench water cooler 6 via a pipe, and the outlet of the quench water cooler 6 is connected to the top of the quench tower 4 via a pipe.

[0076] A quench pump 5 is installed on the pipe connecting the bottom of the quench tower 4 to the quench water cooler 6.

[0077] This embodiment 2 provides a more preferred cooling mechanism based on embodiment 1. Specifically, the cooling mechanism includes a waste heat boiler 3 connected to the hydrogenation reactor 2 and a quench tower 4 connected to the waste heat boiler 3. The top of the quench tower 4 is connected to the tail gas absorption tower 7 via a pipeline. The bottom of the quench tower 4 is connected to a quench water cooler 6 via a pipeline. The outlet of the quench water cooler 6 is connected to the top of the quench tower 4 via a pipeline. A quench pump 5 is installed on the pipeline connecting the bottom of the quench tower 4 to the quench water cooler 6.

[0078] Example 3

[0079] As attached Figure 1 As shown, this embodiment discloses a tail gas desulfurization coupled carbon capture system, including an online combustion furnace 1, a hydrogenation reactor 2, a cooling mechanism, a tail gas absorption tower 7, a tail gas regeneration tower 10, a carbon capture absorption tower 17, and a carbon capture regeneration tower 20 connected in sequence.

[0080] The furnace of the online combustion furnace 1 is connected to a Claus exhaust gas delivery pipe 101, and the burner of the online combustion furnace 1 is connected to a fuel gas delivery pipe 102 and an air delivery pipe 103.

[0081] A high-temperature mixed gas delivery pipe 111 is connected between the online combustion furnace 1 and the hydrogenation reactor 2, which is used to send the combustion gas and the heated Claus tail gas into the hydrogenation reactor 2.

[0082] The hydrogenation reactor 2 is used to reduce SO2 in Claus tail gas to H2S; the tail gas absorption tower 7 is used to absorb H2S and CO2 in the tail gas after hydrogenation reaction, and the tail gas absorption tower 7 is connected to a tail gas output pipe 104.

[0083] The tail gas regeneration tower 10 is used to strip the solution rich in H2S and CO2 to regenerate a mixed acid gas rich in H2S and CO2.

[0084] The carbon capture and absorption tower 17 is used to selectively remove H2S from the mixed acid gas rich in H2S and CO2. The carbon capture and absorption tower 17 is connected to a CO2 gas output pipe 105, which is used to discharge the high CO2 content gas after the H2S has been removed.

[0085] The carbon capture and regeneration tower 20 is used to strip the H2S-containing solution to regenerate H2S-rich gas, and the carbon capture and regeneration tower 20 is connected to an H2S-rich acid gas output pipe 106.

[0086] The cooling mechanism includes a waste heat boiler 3 connected to the hydrogenation reactor 2 and a quench tower 4 connected to the waste heat boiler 3. The top of the quench tower 4 is connected to the tail gas absorption tower 7 via a pipeline.

[0087] The bottom of the quench tower 4 is connected to a quench water cooler 6 via a pipe, and the outlet of the quench water cooler 6 is connected to the top of the quench tower 4 via a pipe.

[0088] A quench pump 5 is installed on the pipe connecting the bottom of the quench tower 4 to the quench water cooler 6.

[0089] The system also includes a tail gas incinerator 27, and the tail gas output pipe 104 is connected to the tail gas incinerator 27.

[0090] This embodiment 3 provides a more preferred implementation method based on embodiment 2, specifically: the system further includes a tail gas incinerator 27, and the tail gas output pipe 104 is connected to the tail gas incinerator 27.

[0091] Example 4

[0092] As attached Figure 1 As shown, this embodiment discloses a tail gas desulfurization coupled carbon capture system, including an online combustion furnace 1, a hydrogenation reactor 2, a cooling mechanism, a tail gas absorption tower 7, a tail gas regeneration tower 10, a carbon capture absorption tower 17, and a carbon capture regeneration tower 20 connected in sequence.

[0093] The furnace of the online combustion furnace 1 is connected to a Claus exhaust gas delivery pipe 101, and the burner of the online combustion furnace 1 is connected to a fuel gas delivery pipe 102 and an air delivery pipe 103.

[0094] A high-temperature mixed gas delivery pipe 111 is connected between the online combustion furnace 1 and the hydrogenation reactor 2, which is used to send the combustion gas and the heated Claus tail gas into the hydrogenation reactor 2.

[0095] The hydrogenation reactor 2 is used to reduce SO2 in Claus tail gas to H2S; the tail gas absorption tower 7 is used to absorb H2S and CO2 in the tail gas after hydrogenation reaction, and the tail gas absorption tower 7 is connected to a tail gas output pipe 104.

[0096] The tail gas regeneration tower 10 is used to strip the solution rich in H2S and CO2 to regenerate a mixed acid gas rich in H2S and CO2.

[0097] The carbon capture and absorption tower 17 is used to selectively remove H2S from the mixed acid gas rich in H2S and CO2. The carbon capture and absorption tower 17 is connected to a CO2 gas output pipe 105, which is used to discharge the high CO2 content gas after the H2S has been removed.

[0098] The carbon capture and regeneration tower 20 is used to strip the H2S-containing solution to regenerate H2S-rich gas, and the carbon capture and regeneration tower 20 is connected to an H2S-rich acid gas output pipe 106.

[0099] The cooling mechanism includes a waste heat boiler 3 connected to the hydrogenation reactor 2 and a quench tower 4 connected to the waste heat boiler 3. The top of the quench tower 4 is connected to the tail gas absorption tower 7 via a pipeline.

[0100] The bottom of the quench tower 4 is connected to a quench water cooler 6 via a pipe, and the outlet of the quench water cooler 6 is connected to the top of the quench tower 4 via a pipe.

[0101] A quench pump 5 is installed on the pipe connecting the bottom of the quench tower 4 to the quench water cooler 6.

[0102] The system also includes a tail gas incinerator 27, and the tail gas output pipe 104 is connected to the tail gas incinerator 27.

[0103] The bottom of the tail gas absorption tower 7 is connected to the tail gas regeneration tower 10 via a tail gas rich liquid conveying pipe 107, and a tail gas lean-rich liquid heat exchanger 9 is installed on the tail gas rich liquid conveying pipe 107.

[0104] The bottom of the tail gas regeneration tower 10 is connected to a tail gas reboiler 11, and the tail gas reboiler 11 is connected to a tail gas lean liquid delivery pipe 108. The tail gas lean liquid delivery pipe 108 passes through the shell side of the tail gas lean and rich liquid heat exchanger 9 and connects to the upper part of the tail gas absorption tower 7.

[0105] A tail gas lean liquid cooler 13 is installed in the part of the tail gas absorption tower 7 between the tail gas absorption tower 7 and the tail gas lean and rich liquid heat exchanger 9.

[0106] A rich liquid pump 8 is installed on the tail gas conveying pipe 107 between the tail gas absorption tower 7 and the tail gas lean liquid heat exchanger 9.

[0107] A lean exhaust gas pump 12 is installed on the exhaust gas lean liquid delivery pipe 108 between the exhaust gas lean liquid cooler 13 and the exhaust gas lean and rich liquid heat exchanger 9.

[0108] This embodiment 4 provides a more preferred implementation of the tail gas absorption tower 7 and the tail gas regeneration tower 10 based on embodiment 3. Specifically, the bottom of the tail gas absorption tower 7 is connected to the tail gas regeneration tower 10 via a tail gas rich liquid conveying pipe 107. A tail gas rich liquid pump 8 and a tail gas lean liquid heat exchanger 9 are sequentially arranged on the tail gas rich liquid conveying pipe 107 in the direction of liquid flow. A tail gas reboiler 11 is connected to the bottom of the tail gas regeneration tower 10. A tail gas lean liquid conveying pipe 108 is connected to the tail gas reboiler 11. The tail gas lean liquid conveying pipe 108 passes through the shell side of the tail gas lean liquid heat exchanger 9 and connects to the upper part of the tail gas absorption tower 7. A tail gas lean liquid pump 12 and a tail gas lean liquid cooler 13 are sequentially arranged between the tail gas absorption tower 7 and the tail gas lean liquid heat exchanger 9 in the direction of liquid flow on the tail gas lean liquid conveying pipe 108.

[0109] Example 5

[0110] As attached Figure 1 As shown, this embodiment discloses a tail gas desulfurization coupled carbon capture system, including an online combustion furnace 1, a hydrogenation reactor 2, a cooling mechanism, a tail gas absorption tower 7, a tail gas regeneration tower 10, a carbon capture absorption tower 17, and a carbon capture regeneration tower 20 connected in sequence.

[0111] The furnace of the online combustion furnace 1 is connected to a Claus exhaust gas delivery pipe 101, and the burner of the online combustion furnace 1 is connected to a fuel gas delivery pipe 102 and an air delivery pipe 103.

[0112] A high-temperature mixed gas delivery pipe 111 is connected between the online combustion furnace 1 and the hydrogenation reactor 2, which is used to send the combustion gas and the heated Claus tail gas into the hydrogenation reactor 2.

[0113] The hydrogenation reactor 2 is used to reduce SO2 in Claus tail gas to H2S; the tail gas absorption tower 7 is used to absorb H2S and CO2 in the tail gas after hydrogenation reaction, and the tail gas absorption tower 7 is connected to a tail gas output pipe 104.

[0114] The tail gas regeneration tower 10 is used to strip the solution rich in H2S and CO2 to regenerate a mixed acid gas rich in H2S and CO2.

[0115] The carbon capture and absorption tower 17 is used to selectively remove H2S from the mixed acid gas rich in H2S and CO2. The carbon capture and absorption tower 17 is connected to a CO2 gas output pipe 105, which is used to discharge the high CO2 content gas after the H2S has been removed.

[0116] The carbon capture and regeneration tower 20 is used to strip the H2S-containing solution to regenerate H2S-rich gas, and the carbon capture and regeneration tower 20 is connected to an H2S-rich acid gas output pipe 106.

[0117] The cooling mechanism includes a waste heat boiler 3 connected to the hydrogenation reactor 2 and a quench tower 4 connected to the waste heat boiler 3. The top of the quench tower 4 is connected to the tail gas absorption tower 7 via a pipeline.

[0118] The bottom of the quench tower 4 is connected to a quench water cooler 6 via a pipe, and the outlet of the quench water cooler 6 is connected to the top of the quench tower 4 via a pipe.

[0119] A quench pump 5 is installed on the pipe connecting the bottom of the quench tower 4 to the quench water cooler 6.

[0120] The system also includes a tail gas incinerator 27, and the tail gas output pipe 104 is connected to the tail gas incinerator 27.

[0121] The bottom of the tail gas absorption tower 7 is connected to the tail gas regeneration tower 10 via a tail gas rich liquid conveying pipe 107, and a tail gas lean-rich liquid heat exchanger 9 is installed on the tail gas rich liquid conveying pipe 107.

[0122] The bottom of the tail gas regeneration tower 10 is connected to a tail gas reboiler 11, and the tail gas reboiler 11 is connected to a tail gas lean liquid delivery pipe 108. The tail gas lean liquid delivery pipe 108 passes through the shell side of the tail gas lean and rich liquid heat exchanger 9 and connects to the upper part of the tail gas absorption tower 7.

[0123] A tail gas lean liquid cooler 13 is installed in the part of the tail gas absorption tower 7 between the tail gas absorption tower 7 and the tail gas lean and rich liquid heat exchanger 9.

[0124] A rich liquid pump 8 is installed on the tail gas conveying pipe 107 between the tail gas absorption tower 7 and the tail gas lean liquid heat exchanger 9.

[0125] A lean exhaust gas pump 12 is installed on the exhaust gas lean liquid delivery pipe 108 between the exhaust gas lean liquid cooler 13 and the exhaust gas lean and rich liquid heat exchanger 9.

[0126] The tail gas desulfurization coupled carbon capture system also includes a tail gas acid gas cooler 15 connected from the top of the tail gas regeneration tower 10 and a tail gas acid gas separator 16 connected from the tail gas acid gas cooler 15. The liquid outlet of the tail gas acid gas separator 16 is connected to the tail gas regeneration tower 10 via a pipeline, and the gas outlet of the tail gas acid gas separator 16 is connected to the carbon capture and absorption tower 17 via a pipeline.

[0127] A tail gas acid water return pump 14 is installed on the pipeline connecting the liquid outlet of the tail gas acid gas separator 16 and the tail gas regeneration tower 10.

[0128] This embodiment 5 provides a more preferred technical solution based on embodiment 4. Specifically, the tail gas desulfurization coupled carbon capture system further includes a tail gas acid gas cooler 15 connected to the top of the tail gas regeneration tower 10 and a tail gas acid gas separator 16 connected to the tail gas acid gas cooler 15. The liquid outlet of the tail gas acid gas separator 16 is connected to the tail gas regeneration tower 10 via a pipeline, and the gas outlet of the tail gas acid gas separator 16 is connected to the carbon capture and absorption tower 17 via a pipeline. A tail gas acid water reflux pump 14 is installed on the pipeline connecting the liquid outlet of the tail gas acid gas separator 16 and the tail gas regeneration tower 10.

[0129] Example 6

[0130] As attached Figure 1 As shown, this embodiment discloses a tail gas desulfurization coupled carbon capture system, including an online combustion furnace 1, a hydrogenation reactor 2, a cooling mechanism, a tail gas absorption tower 7, a tail gas regeneration tower 10, a carbon capture absorption tower 17, and a carbon capture regeneration tower 20 connected in sequence.

[0131] The furnace of the online combustion furnace 1 is connected to a Claus exhaust gas delivery pipe 101, and the burner of the online combustion furnace 1 is connected to a fuel gas delivery pipe 102 and an air delivery pipe 103.

[0132] A high-temperature mixed gas delivery pipe 111 is connected between the online combustion furnace 1 and the hydrogenation reactor 2, which is used to send the combustion gas and the heated Claus tail gas into the hydrogenation reactor 2.

[0133] The hydrogenation reactor 2 is used to reduce SO2 in Claus tail gas to H2S; the tail gas absorption tower 7 is used to absorb H2S and CO2 in the tail gas after hydrogenation reaction, and the tail gas absorption tower 7 is connected to a tail gas output pipe 104.

[0134] The tail gas regeneration tower 10 is used to strip the solution rich in H2S and CO2 to regenerate a mixed acid gas rich in H2S and CO2.

[0135] The carbon capture and absorption tower 17 is used to selectively remove H2S from the mixed acid gas rich in H2S and CO2. The carbon capture and absorption tower 17 is connected to a CO2 gas output pipe 105, which is used to discharge the high CO2 content gas after the H2S has been removed.

[0136] The carbon capture and regeneration tower 20 is used to strip the H2S-containing solution to regenerate H2S-rich gas, and the carbon capture and regeneration tower 20 is connected to an H2S-rich acid gas output pipe 106.

[0137] The cooling mechanism includes a waste heat boiler 3 connected to the hydrogenation reactor 2 and a quench tower 4 connected to the waste heat boiler 3. The top of the quench tower 4 is connected to the tail gas absorption tower 7 via a pipeline.

[0138] The bottom of the quench tower 4 is connected to a quench water cooler 6 via a pipe, and the outlet of the quench water cooler 6 is connected to the top of the quench tower 4 via a pipe.

[0139] A quench pump 5 is installed on the pipe connecting the bottom of the quench tower 4 to the quench water cooler 6.

[0140] The system also includes a tail gas incinerator 27, and the tail gas output pipe 104 is connected to the tail gas incinerator 27.

[0141] The bottom of the tail gas absorption tower 7 is connected to the tail gas regeneration tower 10 via a tail gas rich liquid conveying pipe 107, and a tail gas lean-rich liquid heat exchanger 9 is installed on the tail gas rich liquid conveying pipe 107.

[0142] The bottom of the tail gas regeneration tower 10 is connected to a tail gas reboiler 11, and the tail gas reboiler 11 is connected to a tail gas lean liquid delivery pipe 108. The tail gas lean liquid delivery pipe 108 passes through the shell side of the tail gas lean and rich liquid heat exchanger 9 and connects to the upper part of the tail gas absorption tower 7.

[0143] A tail gas lean liquid cooler 13 is installed in the part of the tail gas absorption tower 7 between the tail gas absorption tower 7 and the tail gas lean and rich liquid heat exchanger 9.

[0144] A rich liquid pump 8 is installed on the tail gas conveying pipe 107 between the tail gas absorption tower 7 and the tail gas lean liquid heat exchanger 9.

[0145] A lean exhaust gas pump 12 is installed on the exhaust gas lean liquid delivery pipe 108 between the exhaust gas lean liquid cooler 13 and the exhaust gas lean and rich liquid heat exchanger 9.

[0146] The tail gas desulfurization coupled carbon capture system also includes a tail gas acid gas cooler 15 connected from the top of the tail gas regeneration tower 10 and a tail gas acid gas separator 16 connected from the tail gas acid gas cooler 15. The liquid outlet of the tail gas acid gas separator 16 is connected to the tail gas regeneration tower 10 via a pipeline, and the gas outlet of the tail gas acid gas separator 16 is connected to the carbon capture and absorption tower 17 via a pipeline.

[0147] A tail gas acid water return pump 14 is installed on the pipeline connecting the liquid outlet of the tail gas acid gas separator 16 and the tail gas regeneration tower 10.

[0148] The bottom of the carbon capture absorption tower 17 is connected to the carbon capture regeneration tower 20 via a carbon capture rich liquid conveying pipe 109. A carbon capture lean and rich liquid heat exchanger 19 is installed on the carbon capture rich liquid conveying pipe 109.

[0149] The bottom of the carbon capture regeneration tower 20 is connected to a carbon capture reboiler 21, and the carbon capture reboiler 21 is connected to a carbon capture lean liquor delivery pipe 110. The carbon capture lean liquor delivery pipe 110 passes through the shell side of the carbon capture lean and rich liquor heat exchanger 19 and connects to the upper part of the carbon capture absorption tower 17.

[0150] A carbon capture lean liquor cooler 23 is installed on the carbon capture lean liquor conveying pipe 110 between the carbon capture absorption tower 17 and the carbon capture lean and rich liquor heat exchanger 19.

[0151] A carbon capture rich liquid pump 18 is installed on the carbon capture rich liquid conveying pipe 109 between the carbon capture absorption tower 17 and the carbon capture lean rich liquid heat exchanger 19.

[0152] A carbon capture lean liquor pump 22 is installed on the carbon capture lean liquor delivery pipe 110 between the carbon capture lean liquor cooler 23 and the carbon capture lean and rich liquor heat exchanger 19.

[0153] This embodiment 6 provides a more preferred implementation method based on embodiment 5. Specifically: the bottom of the carbon capture absorption tower 17 is connected to the carbon capture regeneration tower 20 via a carbon capture rich liquid conveying pipe 109. A carbon capture rich liquid pump 18 and a carbon capture lean-rich liquid heat exchanger 19 are sequentially arranged on the carbon capture rich liquid conveying pipe 109 in the direction of liquid flow. A carbon capture reboiler 21 is connected to the bottom of the carbon capture reboiler 20. A carbon capture lean liquid conveying pipe 110 is connected to the carbon capture reboiler 21. The carbon capture lean liquid conveying pipe 110 passes through the shell side of the carbon capture lean-rich liquid heat exchanger 19 and enters the upper part of the carbon capture absorption tower 17. A carbon capture lean liquid pump 22 and a carbon capture lean liquid cooler 23 are sequentially arranged on the carbon capture lean liquid conveying pipe 110 between the carbon capture lean-rich liquid heat exchanger 19 and the carbon capture absorption tower 17 in the direction of liquid flow.

[0154] Example 7

[0155] As attached Figure 1 As shown, this embodiment discloses a tail gas desulfurization coupled carbon capture system, including an online combustion furnace 1, a hydrogenation reactor 2, a cooling mechanism, a tail gas absorption tower 7, a tail gas regeneration tower 10, a carbon capture absorption tower 17, and a carbon capture regeneration tower 20 connected in sequence.

[0156] The furnace of the online combustion furnace 1 is connected to a Claus exhaust gas delivery pipe 101, and the burner of the online combustion furnace 1 is connected to a fuel gas delivery pipe 102 and an air delivery pipe 103.

[0157] A high-temperature mixed gas delivery pipe 111 is connected between the online combustion furnace 1 and the hydrogenation reactor 2, which is used to send the combustion gas and the heated Claus tail gas into the hydrogenation reactor 2.

[0158] The hydrogenation reactor 2 is used to reduce SO2 in Claus tail gas to H2S; the tail gas absorption tower 7 is used to absorb H2S and CO2 in the tail gas after hydrogenation reaction, and the tail gas absorption tower 7 is connected to a tail gas output pipe 104.

[0159] The tail gas regeneration tower 10 is used to strip the solution rich in H2S and CO2 to regenerate a mixed acid gas rich in H2S and CO2.

[0160] The carbon capture and absorption tower 17 is used to selectively remove H2S from the mixed acid gas rich in H2S and CO2. The carbon capture and absorption tower 17 is connected to a CO2 gas output pipe 105, which is used to discharge the high CO2 content gas after the H2S has been removed.

[0161] The carbon capture and regeneration tower 20 is used to strip the H2S-containing solution to regenerate H2S-rich gas, and the carbon capture and regeneration tower 20 is connected to an H2S-rich acid gas output pipe 106.

[0162] The cooling mechanism includes a waste heat boiler 3 connected to the hydrogenation reactor 2 and a quench tower 4 connected to the waste heat boiler 3. The top of the quench tower 4 is connected to the tail gas absorption tower 7 via a pipeline.

[0163] The bottom of the quench tower 4 is connected to a quench water cooler 6 via a pipe, and the outlet of the quench water cooler 6 is connected to the top of the quench tower 4 via a pipe.

[0164] A quench pump 5 is installed on the pipe connecting the bottom of the quench tower 4 to the quench water cooler 6.

[0165] The system also includes a tail gas incinerator 27, and the tail gas output pipe 104 is connected to the tail gas incinerator 27.

[0166] The bottom of the tail gas absorption tower 7 is connected to the tail gas regeneration tower 10 via a tail gas rich liquid conveying pipe 107, and a tail gas lean-rich liquid heat exchanger 9 is installed on the tail gas rich liquid conveying pipe 107.

[0167] The bottom of the tail gas regeneration tower 10 is connected to a tail gas reboiler 11, and the tail gas reboiler 11 is connected to a tail gas lean liquid delivery pipe 108. The tail gas lean liquid delivery pipe 108 passes through the shell side of the tail gas lean and rich liquid heat exchanger 9 and connects to the upper part of the tail gas absorption tower 7.

[0168] A tail gas lean liquid cooler 13 is installed in the part of the tail gas absorption tower 7 between the tail gas absorption tower 7 and the tail gas lean and rich liquid heat exchanger 9.

[0169] A rich liquid pump 8 is installed on the tail gas conveying pipe 107 between the tail gas absorption tower 7 and the tail gas lean liquid heat exchanger 9.

[0170] A lean exhaust gas pump 12 is installed on the exhaust gas lean liquid delivery pipe 108 between the exhaust gas lean liquid cooler 13 and the exhaust gas lean and rich liquid heat exchanger 9.

[0171] The tail gas desulfurization coupled carbon capture system also includes a tail gas acid gas cooler 15 connected from the top of the tail gas regeneration tower 10 and a tail gas acid gas separator 16 connected from the tail gas acid gas cooler 15. The liquid outlet of the tail gas acid gas separator 16 is connected to the tail gas regeneration tower 10 via a pipeline, and the gas outlet of the tail gas acid gas separator 16 is connected to the carbon capture and absorption tower 17 via a pipeline.

[0172] A tail gas acid water return pump 14 is installed on the pipeline connecting the liquid outlet of the tail gas acid gas separator 16 and the tail gas regeneration tower 10.

[0173] The bottom of the carbon capture absorption tower 17 is connected to the carbon capture regeneration tower 20 via a carbon capture rich liquid conveying pipe 109. A carbon capture lean and rich liquid heat exchanger 19 is installed on the carbon capture rich liquid conveying pipe 109.

[0174] The bottom of the carbon capture regeneration tower 20 is connected to a carbon capture reboiler 21, and the carbon capture reboiler 21 is connected to a carbon capture lean liquor delivery pipe 110. The carbon capture lean liquor delivery pipe 110 passes through the shell side of the carbon capture lean and rich liquor heat exchanger 19 and connects to the upper part of the carbon capture absorption tower 17.

[0175] A carbon capture lean liquor cooler 23 is installed on the carbon capture lean liquor conveying pipe 110 between the carbon capture absorption tower 17 and the carbon capture lean and rich liquor heat exchanger 19.

[0176] A carbon capture rich liquid pump 18 is installed on the carbon capture rich liquid conveying pipe 109 between the carbon capture absorption tower 17 and the carbon capture lean rich liquid heat exchanger 19.

[0177] A carbon capture lean liquor pump 22 is installed on the carbon capture lean liquor delivery pipe 110 between the carbon capture lean liquor cooler 23 and the carbon capture lean and rich liquor heat exchanger 19.

[0178] The exhaust gas desulfurization coupled carbon capture system also includes a carbon capture cooler 24 and a carbon capture acid gas separator 26 connected from the carbon capture cooler 24; the H2S-rich acid gas output pipe 106 is connected to the carbon capture cooler 24.

[0179] The liquid outlet of the carbon capture acid gas separator 26 is connected to the carbon capture regeneration tower 20 via a pipeline, and the gas outlet of the carbon capture acid gas separator 26 is connected to the sulfur recovery device via a pipeline.

[0180] A carbon capture acid water reflux pump 25 is installed on the pipeline connecting the liquid outlet of the carbon capture acid gas separator 26 to the carbon capture regeneration tower 20.

[0181] This embodiment 7 provides a more preferred implementation method based on embodiment 6. Specifically, the tail gas desulfurization coupled carbon capture system further includes a carbon capture cooler 24 and a carbon capture acid gas separator 26 connected to the carbon capture cooler 24; the H2S-rich acid gas output pipe 106 is connected to the carbon capture cooler 24; the liquid outlet of the carbon capture acid gas separator 26 is connected to the carbon capture regeneration tower 20 via a pipeline, and the gas outlet of the carbon capture acid gas separator 26 is connected to the sulfur recovery device via a pipeline; a carbon capture acid water reflux pump 25 is installed on the pipeline connecting the liquid outlet of the carbon capture acid gas separator 26 and the carbon capture regeneration tower 20.

[0182] Example 8

[0183] This embodiment discloses the exhaust gas desulfurization coupled carbon capture process of the present invention, which is carried out using the system of Example 7. The specific steps are as follows:

[0184] Step 1: Air and fuel gas undergo subequivalent combustion in online combustion furnace 1 to produce H2 and CO, while simultaneously heating the Claus tail gas to 280°C; Step 2: The high-temperature mixed gas (combustion gas and heated Claus tail gas) exiting online combustion furnace 1 enters hydrogenation reactor 2, where SO2 in the mixed gas is reduced to H2S under the action of hydrogenation catalyst, and the temperature of the mixed gas is approximately 280°C.

[0185] Step 3: The mixed gas from hydrogenation reactor 2 enters waste heat boiler 3 for waste heat recovery. The temperature of the mixed gas is reduced to 165℃ by producing low-pressure steam of 0.45-0.6 MPa.g.

[0186] Step 4: The 165°C mixed gas from the waste heat boiler 3 enters the quench tower 4 and undergoes countercurrent heat exchange through direct contact with 40°C quench water. The mixed gas at the top of the quench tower 4, at approximately 40°C, enters the absorption tower 7, while the quench water at the bottom of the tower is cooled by the quench water pump 5 and the quench water cooler 6 and then recycled.

[0187] Step 5: The mixed gas entering the tail gas absorption tower 7 is absorbed by the MDEA solution and discharged from the top of the tower. Then it is burned to 600°C in the tail gas incinerator 27 and cooled to 300°C after waste heat recovery before being discharged in compliance with standards.

[0188] The solution rich in H2S and CO2 at the bottom of the tail gas absorption tower 7 enters the tail gas regeneration tower 10 after passing through the tail gas rich liquid pump 8 and the tail gas lean and rich liquid heat exchanger 9.

[0189] Step 6: The solution rich in H2S and CO2 is stripped by steam in the tail gas regeneration tower 10. The semi-lean liquid at the bottom of the tail gas regeneration tower 10 enters the tail gas reboiler 11 for heating, and then exchanges heat with the solution rich in H2S and CO2 through the tail gas lean and rich liquid heat exchanger (9). After being cooled by the tail gas lean liquid cooler 13, it is circulated back into the tail gas absorption tower 7. The mixed gas rich in H2S and CO2 is discharged from the top of the tail gas regeneration tower 10, cooled to 40°C and separated into liquids before entering the carbon capture and absorption tower 17.

[0190] Step 7: The mixed gas rich in H2S and CO2 that enters the carbon capture and absorption tower 17 is selectively desorbed by MDEA compound sterically hindered amine solution. After the H2S is removed, the high CO2 gas is discharged from the top of the carbon capture and absorption tower 17 and sent to the downstream liquefaction unit.

[0191] The H2S-rich solution at the bottom of the carbon capture absorption tower 17 enters the carbon capture regeneration tower 20 after passing through the carbon capture rich liquid pump 18 and the carbon capture lean and rich liquid heat exchanger 19.

[0192] Step 8: The H2S-rich solution is stripped by steam in the carbon capture and regeneration tower 20. The H2S-rich gas is discharged from the top of the carbon capture and regeneration tower 20, cooled to 40°C, separated into liquids, and returned to the sulfur recovery unit.

[0193] The semi-lean liquor at the bottom of the carbon capture regeneration tower 20 enters the carbon capture reboiler 21 for heating, and then exchanges heat with the H2S-rich solution through the carbon capture lean and rich liquor heat exchanger 19. After being cooled by the carbon capture lean liquor cooler 17, it is circulated back into the carbon capture absorption tower 17.

[0194] The working principle of this invention is as follows: After the Claus tail gas undergoes a hydrogenation reduction reaction, SO2 in the tail gas is converted into H2S. H2S and CO2 are completely absorbed by a low-pressure total solvent removal process. Then, H2S and CO2 are released through solution regeneration. After selective solution removal of H2S, the separation of H2S and CO2 is achieved, thus achieving the purpose of CO2 capture.

[0195] This invention effectively combines the Claus exhaust gas reduction and absorption process with the CO2 capture process, featuring low energy consumption and low investment. It can both ensure that exhaust gas emissions meet stringent emission standards and achieve the goal of CO2 capture and emission reduction, demonstrating good operability and environmental friendliness.

[0196] The above description is merely a preferred embodiment of the present invention and is illustrative in nature, not intended to limit the scope of the invention. Various modifications and improvements made to the technical solutions of the present invention by those skilled in the art without departing from the spirit of the invention should fall within the protection scope defined by the claims.

Claims

1. A tail gas desulfurization coupled carbon capture system, characterized in that, It includes an online combustion furnace (1), a hydrogenation reactor (2), a cooling mechanism, a tail gas absorption tower (7), a tail gas regeneration tower (10), a carbon capture and absorption tower (17), and a carbon capture and regeneration tower (20) connected in sequence; The furnace of the online combustion furnace (1) is connected to a Claus exhaust gas delivery pipe (101), and the burner of the online combustion furnace (1) is connected to a fuel gas delivery pipe (102) and an air delivery pipe (103). The tail gas absorption tower (7) is connected to a tail gas output pipe (104), the carbon capture absorption tower (17) is connected to a CO2 gas output pipe (105), and the carbon capture regeneration tower (20) is connected to an H2S-rich acid gas output pipe (106).

2. The exhaust gas desulfurization coupled carbon capture system according to claim 1, characterized in that, The cooling mechanism includes a waste heat boiler (3) connected to the hydrogenation reactor (2) and a quench tower (4) connected to the waste heat boiler (3), the top of which is connected to the tail gas absorption tower (7) via a pipeline. Preferably, the bottom of the quench tower (4) is connected to a quench water cooler (6) via a pipe, and the outlet of the quench water cooler (6) is connected to the top of the quench tower (4) via a pipe. More preferably, a quench pump (5) is installed on the pipe connecting the bottom of the quench tower (4) to the quench water cooler (6).

3. A tail gas desulfurization coupled carbon capture system according to claim 1 or 2, characterized in that, It also includes a tail gas incinerator (27), and the tail gas output pipe (104) is connected to the tail gas incinerator (27).

4. A tail gas desulfurization coupled carbon capture system according to claim 1 or 2, characterized in that, The bottom of the tail gas absorption tower (7) is connected to the tail gas regeneration tower (10) via a tail gas rich liquid conveying pipe (107), and a tail gas lean-rich liquid heat exchanger (9) is installed on the tail gas rich liquid conveying pipe (107). The bottom of the tail gas regeneration tower (10) is connected to a tail gas reboiler (11), and the tail gas reboiler (11) is connected to a tail gas lean liquid delivery pipe (108). The tail gas lean liquid delivery pipe (108) passes through the shell side of the tail gas lean and rich liquid heat exchanger (9) and connects to the upper part of the tail gas absorption tower (7). Preferably, a tail gas lean liquid cooler (13) is provided in the part of the tail gas lean liquid conveying pipe (108) between the tail gas absorption tower (7) and the tail gas lean and rich liquid heat exchanger (9). Preferably, a tail gas rich liquid pump (8) is installed on the tail gas rich liquid conveying pipe (107) between the tail gas absorption tower (7) and the tail gas lean rich liquid heat exchanger (9). Preferably, a tail gas lean liquid pump (12) is provided on the tail gas lean liquid delivery pipe (108) between the tail gas lean liquid cooler (13) and the tail gas lean and rich liquid heat exchanger (9).

5. A tail gas desulfurization coupled carbon capture system according to claim 1 or 2, characterized in that, It also includes a tail gas acid gas cooler (15) connected from the top of the tail gas regeneration tower (10) and a tail gas acid gas separator (16) connected from the tail gas acid gas cooler (15). The liquid outlet of the tail gas acid gas separator (16) is connected to the tail gas regeneration tower (10) via a pipeline, and the gas outlet of the tail gas acid gas separator (16) is connected to the carbon capture and absorption tower (17) via a pipeline. Preferably, a tail gas acid water return pump (14) is installed on the pipeline connecting the liquid outlet of the tail gas acid gas separator (16) and the tail gas regeneration tower (10).

6. A tail gas desulfurization coupled carbon capture system according to claim 1 or 2, characterized in that, The bottom of the carbon capture absorption tower (17) is connected to the carbon capture regeneration tower (20) via a carbon capture rich liquid conveying pipe (109), and a carbon capture lean-rich liquid heat exchanger (19) is installed on the carbon capture rich liquid conveying pipe (109). The bottom of the carbon capture regeneration tower (20) is connected to a carbon capture reboiler (21), and the carbon capture reboiler (21) is connected to a carbon capture lean liquor delivery pipe (110). The carbon capture lean liquor delivery pipe (110) passes through the shell side of the carbon capture lean and rich liquor heat exchanger (19) and connects to the upper part of the carbon capture absorption tower (17). Preferably, a carbon capture lean liquor cooler (23) is provided on the carbon capture lean liquor conveying pipe (110) between the carbon capture absorption tower (17) and the carbon capture lean and rich liquor heat exchanger (19); Preferably, a carbon capture rich liquid pump (18) is installed on the carbon capture rich liquid conveying pipe (109) between the carbon capture absorption tower (17) and the carbon capture lean rich liquid heat exchanger (19); Preferably, a carbon capture lean liquor pump (22) is provided on the carbon capture lean liquor delivery pipe (110) between the carbon capture lean liquor cooler (23) and the carbon capture lean and rich liquor heat exchanger (19).

7. A tail gas desulfurization coupled carbon capture system according to claim 1 or 2, characterized in that, It also includes a carbon capture cooler (24) and a carbon capture acid gas separator (26) connected from the carbon capture cooler (24); the H2S-rich acid gas output pipe (106) is connected to the carbon capture cooler (24); The liquid outlet of the carbon capture acid gas separator (26) is connected to the carbon capture regeneration tower (20) via a pipeline, and the gas outlet of the carbon capture acid gas separator (26) is connected to the sulfur recovery device via a pipeline. Preferably, a carbon capture acid gas separator (26) is provided with a carbon capture acid water reflux pump (25) on the pipeline connecting the liquid outlet of the carbon capture acid gas separator (26) to the carbon capture regeneration tower (20).

8. A tail gas desulfurization coupled carbon capture process, characterized in that, The system described in any one of claims 1-7 shall be used.

9. The tail gas desulfurization coupled carbon capture process according to claim 8, characterized in that, Includes the following steps: Step 1: Air, fuel gas, and air-Claus tail gas are fed into the online combustion furnace. The air and fuel gas undergo subequivalent combustion in the online combustion furnace to produce H2 and CO, while simultaneously heating the Claus tail gas. The combusted gas and the heated Claus tail gas exit the online combustion furnace, forming a high-temperature mixed gas. Step 2: The high-temperature mixed gas from the online combustion furnace enters the hydrogenation reactor, where SO2 in the mixed gas is reduced to H2S under the action of a catalyst. Step 3: The mixed gas exiting the hydrogenation reactor is cooled by a cooling mechanism and then enters the tail gas absorption tower; Step 4: The mixed gas entering the tail gas absorption tower is absorbed by the solution and then discharged from the top of the tower; the solution rich in H2S and CO2 at the bottom of the tail gas absorption tower enters the tail gas regeneration tower. Step 5: The solution rich in H2S and CO2 is stripped by steam in the tail gas regeneration tower, and the mixed gas rich in H2S and CO2 is discharged from the tail gas regeneration tower and enters the carbon capture and absorption tower. Step 6: The mixed gas rich in H2S and CO2 that enters the carbon capture and absorption tower undergoes selective removal of H2S through solution absorption, and then the high CO2 gas discharged from the top of the tower, while the H2S-rich solution at the bottom of the carbon capture and absorption tower enters the carbon capture and regeneration tower. Step 7: The H2S-rich solution is stripped by steam in the carbon capture and regeneration tower, and the H2S-rich mixed gas is discharged from the top of the carbon capture and regeneration tower and returned to the sulfur recovery unit.

10. The tail gas desulfurization coupled carbon capture process according to claim 8, characterized in that, In step one, the Claus exhaust gas is heated to 260-300°C, preferably 280°C; In step three, the mixed gas exiting the hydrogenation reactor is cooled to 30-50°C, preferably 40°C, by a cooling mechanism before entering the tail gas absorption tower. In step five, the mixed gas rich in H2S and CO2 is discharged from the tail gas regeneration tower, cooled to 30-50°C by a cooling mechanism, preferably 40°C, and then enters the carbon capture and absorption tower.

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