Gas oxidation treatment and carbon capture comprehensive utilization method and device

Abstract

The invention provides a gas oxidation treatment and carbon capture comprehensive utilization method and device. The device comprises a gas oxidation treatment power generation system, a heat recovery system, a carbon capture system, a carbon dioxide refining system, an energy recovery system, a carbon dioxide gasification system, a carbon conversion system and a heat exchange system. The gas oxidation treatment power generation system is connected with the heat recovery system and the carbon dioxide refining system, the gas oxidation treatment power generation system and the heat recovery system are connected with the carbon capture system and the carbon dioxide refining system, the carbon capture system is connected with the carbon dioxide refining system, and the energy recovery system is connected with the carbon dioxide refining system. The carbon dioxide gasification system is connected with the carbon dioxide refining system and the carbon conversion system. According to the invention, the energy of all gases in the system is fully recycled, the exhausted gases completely reach the environmental protection standard, energy is saved, emission is reduced, carbon dioxide is recovered and refined through carbon capture, and the refined carbon dioxide is further converted into chemicals and fuels such as methanol, methane, formic acid, carbon monoxide and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon capture, recycling and carbon conversion, and in particular to a method and device for gas oxidation treatment and carbon capture and comprehensive utilization. Background Art

[0002] At present, excessive emissions of greenhouse gases have led to the continuous strengthening of the greenhouse effect, which has had an adverse impact on the global climate. Carbon dioxide is the most important part of greenhouse gases, and reducing its emissions is seen as the most important way to solve climate problems.

[0003] Clean energy processed by clean technology mainly refers to the efficient and low-pollution processing of fossil fuels through advanced clean technology, thereby reducing the emission of pollutants such as sulfides and nitrogen compounds. This treatment method can not only effectively reduce pollution, but also improve the utilization rate of energy, achieving a win-win situation in terms of economic and environmental benefits of energy.

[0004] In the power industry, clean energy processed by clean technology mainly includes coal gasification, fuel cells, etc. These technologies can effectively improve the utilization rate of fuels, reduce the emission of pollutants such as sulfides and nitrides, and play an important role in improving the environmental conditions of the power industry. In the industrial field, clean energy processed by clean technology mainly includes industrial waste heat recovery, industrial waste gas treatment, etc. The application of these technologies can not only improve the efficiency of industrial production, but also effectively reduce environmental pollution.

[0005] Fossil resources such as coal, oil, and natural gas provide energy for the development of modern society, but the increasing CO2 emissions have caused serious harm to humans and the environment. In 2018, global CO2 emissions were about 42.1Gt, of which 36.6Gt (87%) came from fossil fuel-based energy systems and chemical industries. For the existing fossil energy industrial system, carbon capture and storage (CCS) technology is the most effective way to reduce CO2 emissions.

[0006] At present, there are more than 300 CCS industrial and demonstration projects in the world, but the overall scale is far from meeting the rapidly growing needs of society. The main reason is that the cost of CCS technology is high, and the sustainability and safety of storing captured CO2 are questionable. Therefore, developing carbon capture and utilization (CCU) technology to convert captured CO2 into high-value-added chemicals and fuels, thereby realizing the resource utilization of CO2, is an important carbon emission reduction technology, which is of great significance to alleviating the energy crisis and achieving carbon neutrality.

[0007] At present, the country focuses on advocating to increase the application of advanced energy-saving technologies, promote the optimization of energy use in systems such as heat exchange, steam power, waste heat and pressure, and distillation, carry out cooperation in steam and electricity supply, and realize the complementarity and sharing of thermal power resources. Combining environmental protection, energy conservation and carbon reduction in power generation with carbon capture can promote the reduction of energy consumption intensity, reduce carbon dioxide emissions, and help my country achieve its dual carbon goals as soon as possible.

[0008] Therefore, it is necessary to provide a comprehensive utilization device combining gas oxidation treatment and carbon capture to solve the above problems. Summary of the invention

[0009] According to the above-mentioned efficient utilization of clean energy processed by clean technology, how to solve the technical problem of combining power generation, environmental protection, energy saving and carbon reduction with carbon capture, and provide a method and device for comprehensive utilization of gas oxidation treatment and carbon capture. The present invention mainly utilizes gas oxidation treatment power generation system, heat recovery system, carbon capture system, carbon dioxide refining system, carbon dioxide gasification system, carbon conversion system and heat exchange system to optimize the recovery and utilization of energy in the entire system, greatly reducing the operating cost of carbon capture and refining, and further converting the captured carbon dioxide into high-value-added chemicals and fuels such as methanol, methane, formic acid, carbon monoxide, thereby realizing the resource utilization of carbon dioxide, while solving the problems of gas energy-saving utilization, environmental protection treatment, carbon capture, recovery and refining, and carbon conversion, and is an important carbon emission reduction technology.

[0010] The technical means adopted by the present invention are as follows:

[0011] A gas oxidation treatment and carbon capture comprehensive utilization device, comprising: a gas oxidation treatment power generation system, a heat recovery system, a carbon capture system, a carbon dioxide refining system, an energy recovery system, a carbon dioxide gasification system, a carbon conversion system and a heat exchange system;

[0012] The gas oxidation power generation system is connected to the heat recovery system and the carbon dioxide refining system to recover the energy of the high-temperature gas generated by oxidation combustion to power the electric generator and the motor of the compressor unit;

[0013] The gas oxidation power generation system and the heat recovery system are connected to the carbon capture system and the carbon dioxide refining system. The gas discharged after the reaction enters the carbon capture system after heat exchange through the heat exchange system, and the steam generated after the reaction is respectively input into the carbon capture system and the carbon dioxide refining system;

[0014] The carbon capture system is connected to the carbon dioxide refining system, and is used to generate a relatively high concentration of carbon dioxide gas and input it into the carbon dioxide refining system. The carbon dioxide refining system is used to generate high-concentration liquid carbon dioxide from the relatively high concentration of carbon dioxide gas and store it. The relatively high concentration of carbon dioxide gas refers to carbon dioxide gas with a concentration of more than 80%, and the high concentration of liquid carbon dioxide refers to liquid carbon dioxide with a concentration of more than 99%;

[0015] The energy recovery system is connected to the carbon dioxide refining system and is used to recover the pressure energy of the exhaust gas from the top of the distillation tower of the carbon dioxide refining system and the exhaust gas from the top of the storage tank through the tail gas turbine to supply power to the electric generator and the motor of the compressor unit;

[0016] The carbon dioxide gasification system is connected to the carbon dioxide refining system and the carbon conversion system, and is used to convert the stored high-concentration liquid carbon dioxide into high-concentration carbon dioxide gas through the heat exchange system, and input it into the carbon conversion system to generate chemicals and fuels.

[0017] Furthermore, the gas oxidation treatment power generation system is composed of a compressor unit and a gas turbine generator unit, the compressor unit includes a compressor and a motor, and the gas turbine generator unit includes a gas turbine, a compressor and an electric generator I. After the compressor pressurizes the gas to be treated, an oxidation combustion reaction occurs with the air sent into the compressor for compression and the gas turbine in the combustion chamber of the gas turbine. The high-temperature and high-pressure gas generated drives the electric generator I to generate electricity, and the generated electric energy is used to power the motor of the compressor unit. When the system is initially started, the electric generator I can also be directly powered by external power to drive the gas turbine and the compressor.

[0018] Furthermore, the gas to be treated contains at least combustible gas, and the combustible gas is one or more streams of hydrocarbon, carbon monoxide or hydrogen gas.

[0019] Furthermore, when the gas to be treated contains VOCs gas, the combustion value of the combustible gas after being mixed and pressurized with the VOCs gas should meet the requirements for combustion in the combustion chamber of the gas turbine, that is, when the combustion value of the VOCs gas is insufficient for combustion, the combustion value is increased by the combustible gas.

[0020] Furthermore, the heat recovery system is a waste heat boiler, and the high-temperature gas exhausted by the gas turbine generates steam through the waste heat boiler. The gas after heat exchange then enters the carbon capture system and the carbon dioxide refining system, and the gas exhausted from the waste heat boiler enters the heat exchange system for heat exchange.

[0021] Furthermore, the carbon dioxide refining system includes a steam turbine compressor unit, a purification tower, a liquefier, a refrigeration system, a distillation tower and a storage tank connected in sequence. Through the compression, purification, liquefaction and distillation processes, the captured high-concentration carbon dioxide gas is converted into high-concentration liquid carbon dioxide and stored in the storage tank; the steam turbine compressor unit is a carbon dioxide compressor unit, which is connected to the carbon capture system and is used to compress the high-concentration carbon dioxide gas generated by the carbon capture system; the purification tower is connected to the steam turbine compressor unit and is used to purify the compressed carbon dioxide gas. The liquefaction process uses a liquefier and a refrigeration system, and the distillation process uses a distillation tower.

[0022] Preferably, the carbon dioxide refining system is further provided with a heat exchanger, which is connected between the purification tower and the liquefier, and the purification tower is connected to a heater, which is connected to the heat exchanger; the exhaust gas from the top of the distillation tower and the exhaust gas from the top of the storage tank are two pressurized low-temperature gases, the two pressurized low-temperature gases are recovered and heat-exchanged with the gas discharged from the purification tower through a heat exchanger to recover the cold, a part of the gas is heated by the heater and used for regeneration of the purification tower, the regenerated gas is merged with the other part of the gas, and the carbon dioxide gas exceeding 1.0MPa after the merger is returned to the carbon capture system after energy recovery through the energy recovery system (the system recovers pressure energy without waste), which not only effectively recovers energy, but also recovers carbon dioxide, thereby improving the carbon capture recovery rate.

[0023] Furthermore, the steam turbine compressor unit includes a steam turbine and a centrifugal compressor and an electric generator II connected to the steam turbine. The steam turbine is connected to a heat recovery system, and uses steam to generate mechanical energy to drive the centrifugal compressor. The centrifugal compressor is connected to a carbon capture system to achieve compression of a relatively high concentration of carbon dioxide gas. When the centrifugal compressor operation requirements are met, excess steam is used to generate electricity through the electric generator II to supply power to other electrical equipment. The insufficient energy to drive the centrifugal compressor is supplemented by the oxidation treatment power generation system and the energy recovery system. The centrifugal compressor can also be started by external power supply.

[0024] Furthermore, the energy recovery system includes a heat exchange system and an exhaust gas turbine unit. The exhaust gas from the top of the distillation tower and the exhaust gas from the top of the storage tank are two pressurized gases with a temperature below zero. The two gases with a temperature below zero are recovered and exchanged with the gas discharged from the purification tower through a heat exchanger to recover the cold. A part of the gas is heated by a heater and used for regeneration of the purification tower. The regenerated gas is merged with the remaining gas. The carbon dioxide gas exceeding 1.0MPa after the merger is returned to the carbon capture system after recovering energy through the energy recovery system.

[0025] Furthermore, the carbon capture system includes three processes of alkaline desulfurization, absorption and desorption, which capture and concentrate low-concentration carbon dioxide (low-concentration carbon dioxide refers to carbon dioxide gas with a concentration of less than 60%) into a higher concentration (more than 80%) carbon dioxide gas, wherein the alkaline desulfurization process adopts a pretreatment tower, the absorption process adopts an absorption tower, and the desorption process adopts a desorption tower; the pretreatment tower, the absorption tower and the desorption tower are connected in sequence; the heat of the desorption tower is provided by the steam generated by the heat recovery system, wherein the desorption tower is connected to a bottom reboiler, and the steam is heat-exchanged through the bottom reboiler to heat the absorbent to achieve desorption regeneration, and the condensed water after heat exchange is transported back to the heat recovery system.

[0026] Preferably, the carbon capture system can also capture carbon dioxide in the form of phase change. Specifically, low-concentration carbon dioxide is captured and concentrated into high-concentration carbon dioxide gas through alkaline washing desulfurization, absorption, phase change, separation, and desorption processes. A pretreatment tower is used in the alkaline washing desulfurization process, an absorption tower is used for the absorption process gas, a liquid storage tank and a phase change separation tank are used in the phase change process, and a desorption tower is used in the desorption process. The pretreatment tower, the absorption tower, the liquid storage tank, the phase change separation tank, and the desorption tower are connected in sequence, and the gas from the top of the absorption tower is directly discharged through the first gas-liquid separation tank; the absorption liquid from the bottom of the absorption tower enters the phase change separation tank through the first heat exchanger, and after phase change separation, the lower liquid phase rich in carbon dioxide enters the desorption tower, and the upper liquid phase without carbon dioxide directly enters the liquid storage tank. After the lower liquid phase decomposes carbon dioxide, it is heat-exchanged with the solution from the absorption tower through the first heat exchanger and then returns to the liquid storage tank; wherein the desorption tower is also connected to a bottom reboiler, and the steam is heat-exchanged through the bottom reboiler to heat the absorbent to achieve desorption regeneration, and the condensed water after heat exchange is transported back to the heat recovery system.

[0027] Furthermore, the carbon dioxide gasification system includes a pressure pump and a precooler. One side of the pressure pump is connected to the storage tank of the carbon dioxide refining system, and the other side is connected to the precooler. The precooler is connected to the heat exchange gasifier. The pressure pump is used to pressurize the stored liquid carbon dioxide to the required pressure, and to exchange heat with the gas discharged from the heat recovery system through the heat exchange gasifier, thereby reducing the temperature of the gas entering the carbon capture system and gasifying the liquid carbon dioxide into gas.

[0028] Furthermore, the carbon conversion system converts carbon dioxide gas into chemicals and fuels through thermal catalysis, electrocatalysis or photocatalysis.

[0029] The present invention also discloses a method for gas oxidation treatment and carbon capture comprehensive utilization, which is carried out using the above-mentioned gas oxidation treatment and carbon capture comprehensive utilization device and comprises the following steps:

[0030] S1. The gas to be treated is pressurized by the compressor and enters the gas turbine. It undergoes oxidation and combustion reaction with the air compressed by the compressor in the combustion chamber of the gas turbine. The high-temperature and high-pressure gas generated drives the compressor to pressurize the air. The excess mechanical energy generated by the gas turbine drives the electric generator I to generate electricity, and the generated electricity is used to power the compressor.

[0031] S2. The high-temperature gas discharged from the gas turbine generates steam and discharges the gas through the waste heat boiler;

[0032] S21. The gas discharged from the waste heat boiler is cooled by heat exchange in the heat exchanger gasifier and then enters the carbon capture system. The gas passes through the pretreatment tower, absorption tower and desorption tower in sequence, that is, the carbon dioxide below 60% is captured and concentrated into more than 80% carbon dioxide gas through alkaline washing desulfurization, absorption and desorption processes; more than 80% carbon dioxide gas enters the carbon dioxide refining system, and passes through the centrifugal compressor, purification tower, liquefier, refrigeration system, distillation tower and storage tank in sequence, that is, more than 80% carbon dioxide gas is converted into more than 99% liquid carbon dioxide through compression, purification, liquefaction and distillation and stored in the storage tank; when preparing chemicals and fuels, the liquid carbon dioxide in the storage tank is converted into carbon dioxide gas through a pressure pump, a precooler and a heat exchanger gasifier, and the carbon dioxide gas is further converted into chemicals and fuels through a carbon conversion system by reacting with hydrogen;

[0033] S22. A portion of the steam generated by the waste heat boiler is supplied to the desorption tower in the carbon capture system to heat the absorbent for desorption and regeneration, and the other portion is supplied to the steam turbine of the carbon dioxide refining system to generate mechanical energy to drive the centrifugal compressor to compress the carbon dioxide. The excess steam can be used to drive the electric generator II through the steam turbine to generate electricity and be supplied to other electrical equipment in the system, such as the combustible gas compressor;

[0034] S3. The distillation tower and storage tank are pressure vessels and need to be vented. The exhaust gas from the top of the distillation tower and the top of the storage tank are two streams of carbon dioxide gas with a pressure below zero and greater than 1.0MPa. The two streams of pressurized low-temperature gases are heat-exchanged with the gas discharged from the purification tower to recover cold energy. A part of the gas is heated by a heater and used for regeneration of the purification tower. The regenerated gas is combined with the remaining gas. The carbon dioxide gas with a pressure exceeding 1.0MPa after the combination is recovered through the energy recovery system and then returned to the carbon capture system. This not only effectively recovers energy, but also recovers carbon dioxide, thereby improving the carbon capture recovery rate.

[0035] Compared with the prior art, the present invention has the following advantages:

[0036] 1. The gas oxidation treatment and carbon capture comprehensive utilization device provided by the present invention uses a gas turbine and a generator, and together with a waste heat boiler and a steam turbine, forms a combined cycle power generation. It can not only use gas fuel to generate electricity, but also oxidize and environmentally treat VOCs-containing gases to generate electricity. The exhaust gas is combined with carbon capture, and the entire process achieves zero carbon emissions.

[0037] The working medium of the gas turbine used in the present invention is gas, and it uses natural gas or synthetic gas. Its main advantages are: quick start and stop, good peak-shaving performance; high cycle thermal efficiency; using natural gas or synthetic gas as fuel, less pollution, high combustion efficiency; no need for coal yard, coal transportation system, ash removal system, small plant area; low water consumption, etc. The gas turbine is applied to the clean energy power generation field and industrial waste gas treatment field treated by clean technology, with its advantages of high efficiency and low pollution, making greater contributions to the sustainable development of mankind.

[0038] 2. In the gas oxidation treatment and carbon capture comprehensive utilization device provided by the present invention, after the combustible gas is pressurized by the compressor, it undergoes an oxidation combustion reaction in the combustion chamber of the gas turbine together with the air compressed by the compressor. The high-temperature and high-pressure gas generated rotates the gas turbine to provide mechanical energy for the compressor. The excess mechanical energy drives the electric generator I to generate electricity, and the generated electricity is used to power the combustible gas compressor. The high-temperature flue gas discharged by the gas turbine passes through the waste heat boiler to produce by-product steam. The gas coming out of the waste heat boiler is cooled by heat exchange and enters the carbon capture system. The low-concentration carbon dioxide is captured and concentrated into a higher-concentration carbon dioxide gas through the alkaline washing desulfurization, absorption and desorption processes. The higher-concentration carbon dioxide gas enters the carbon dioxide refining system, is compressed, purified, liquefied and distilled by the steam turbine compressor unit into high-purity liquid carbon dioxide and stored in a storage tank, and then passes through the gasification system to become high-purity gas. The high-purity carbon dioxide is further converted into high-value-added chemicals and fuels.

[0039] 3. The gas oxidation treatment and carbon capture comprehensive utilization device provided by the present invention optimizes the energy recovery and utilization in the entire system, greatly reduces the operating cost of carbon capture and refining, and converts the captured carbon dioxide into high-value-added chemicals and fuels, thereby realizing the resource utilization of carbon dioxide. At the same time, it solves the problems of efficient utilization of clean energy, environmental protection, energy saving and carbon reduction, carbon capture, recovery and refining, and carbon conversion in clean technology treatment, and is an important carbon emission reduction technology. In addition, the pressure and temperature of all exhaust gases have been recycled and the environmental protection standards are met.

[0040] In summary, the application of the technical solution of the present invention can solve the problem that a large amount of pressurized high-temperature gas currently discharged is only recovered through measures such as decompression waste heat recovery, which wastes a lot of pressure energy. The energy consumption of heat exchange, steam power, waste heat and pressure, distillation and other systems has been optimized, and steam and electricity mutual supply cooperation has been carried out to achieve complementary and sharing of thermal and electric resources.

[0041] Based on the above reasons, the present invention can be widely promoted in the fields of efficient utilization of clean energy processed by clean technology, power generation, carbon capture and recycling, energy conservation, environmental protection, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0043] Figure 1 This is a schematic diagram of the structure of the gas oxidation treatment and carbon capture comprehensive utilization device provided by the present invention.

[0044] Figure 2 This is a schematic structural diagram of the gas oxidation power generation system and heat recovery system in the gas oxidation treatment and carbon capture comprehensive utilization device provided by the present invention.

[0045] Figure 3 This is a schematic structural diagram of the carbon capture system portion of the gas oxidation treatment and carbon capture comprehensive utilization device provided by the present invention.

[0046] Figure 4 This is a schematic structural diagram of the carbon capture system portion of the gas oxidation treatment and carbon capture comprehensive utilization device provided by the present invention, wherein the carbon capture system adopts a phase change form.

[0047] Figure 5 This is a schematic structural diagram of the carbon dioxide gasification and refining system portion of the gas oxidation treatment and carbon capture and comprehensive utilization device provided by the present invention.

[0048] Figure 6 This is a schematic structural diagram of the carbon conversion system portion of the gas oxidation treatment and carbon capture comprehensive utilization device provided by the present invention.

[0049] In the figure: 1. gas to be treated; 2. air; 3. compressor; 4. motor; 5. gas turbine; 6. compressor; 7. electric generator I; 8. waste heat boiler; 9. boiler feed water; 10. steam; 11. heat exchange gasifier; 12. pretreatment tower; 13. absorption tower; 14. venting air; 15. desorption tower; 16. tower bottom reboiler; 17. gaseous carbon dioxide I; 18. steam turbine; 19. centrifugal compressor; 20. electric generator II; 21. tail gas turbine; 22. electric Generator III; 23. Gaseous carbon dioxide II; 24. Purification tower; 25. Heater; 26. Precooler; 27. Heat exchanger; 28. Liquefier; 29. ​​Refrigeration system; 30. Distillation tower; 31. Storage tank; 32. Booster pump; 33. Hydrogen; 34. Gaseous carbon dioxide product; 35. Carbon conversion system; 36. Chemicals and fuels; 37. First gas-liquid separation tank; 38. Liquid storage tank; 39. Phase change separation tank; 40. Second gas-liquid separation tank; 41. First heat exchanger. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0051] like Figure 1 As shown, the present invention provides a gas oxidation treatment and carbon capture comprehensive utilization device, which belongs to the field of power generation, energy saving, low carbon, environmental protection, carbon capture and recycling technology and carbon conversion.

[0052] The gas oxidation treatment and carbon capture comprehensive utilization device comprises: a gas oxidation treatment power generation system, a heat recovery system, a carbon capture system, a carbon dioxide refining system, an energy recovery system, a carbon dioxide gasification system, a carbon conversion system and a heat exchange system.

[0053] The gas oxidation treatment power generation system is connected to the heat recovery system and the carbon dioxide refining system, and is used to recover the energy of the high-temperature gas generated by oxidation combustion to power the electric generator II and the motor of the compressor unit of the carbon dioxide refining system;

[0054] The gas oxidation power generation system and the heat recovery system are connected to the carbon capture system and the carbon dioxide refining system. The gas discharged after the reaction of the gas oxidation power generation system and the heat recovery system enters the carbon capture system after heat exchange through the heat exchange system, and the steam generated after the reaction is respectively input into the carbon capture system and the carbon dioxide refining system;

[0055] The carbon capture system is connected to a carbon dioxide refining system, and is used to generate a relatively high concentration of carbon dioxide gas and input it into the carbon dioxide refining system. The carbon dioxide refining system is used to generate a high concentration of liquid carbon dioxide from the relatively high concentration of carbon dioxide gas and store it;

[0056] The energy recovery system is connected to the carbon dioxide refining system, and is used to recover the pressure energy of the gas at the top of the distillation tower of the carbon dioxide refining system and the exhaust gas at the top of the storage tank through the tail gas turbine, and generate electricity to supply power to the electric generator III and the motor of the compressor unit. If there is still surplus electricity, it can be supplied between the electric generator I, the electric generator II and the motor, that is, the part shown by the dotted line in the figure, and can also supply electricity to the external grid.

[0057] The carbon dioxide gasification system is connected to the carbon dioxide refining system and the carbon conversion system, and is used to convert the stored high-concentration liquid carbon dioxide into high-concentration carbon dioxide gas through the heat exchange system, and input it into the carbon conversion system to generate chemicals and fuels.

[0058] Example 1

[0059] The present invention provides a gas oxidation treatment and carbon capture comprehensive utilization device, including: a gas oxidation treatment power generation system, a heat recovery system, a carbon capture system, a carbon dioxide refining system, an energy recovery system, a carbon dioxide gasification system, a carbon conversion system and a heat exchange system. The various devices in the system are connected by pipelines, lines, etc.

[0060] In this embodiment, Figure 2 As shown, the gas oxidation treatment power generation system consists of a compressor 3, a motor 4, a gas turbine 5, a compressor 6, and an electric generator I7. The compressor 3 is connected to the motor 4, and the gas turbine 5 is connected to the compressor 6 and the electric generator I7. The gas to be treated 1 contains at least combustible gas, and the combustible gas is one or more hydrocarbons, carbon monoxide or hydrogen gas. When the gas to be treated 1 contains VOCs gas, the combustion value of the combustible gas and the VOCs gas after mixing and pressurizing should meet the requirements of combustion in the combustion chamber of the gas turbine. The gas to be treated 1 is pressurized by the compressor 3 and enters the gas turbine 5, and the air 2 compressed by the compressor 6 is oxidized and burned in the combustion chamber of the gas turbine 5. The excess mechanical energy generated by the gas turbine 5 drives the electric generator I7 to generate electricity, and the generated electricity is used to power the motor 4 of the compressor. When the system is initially started, the motor 4 and the electric generator I7 can be directly powered by external power to drive the compressor 3 and the gas turbine 5.

[0061] In this embodiment, the heat recovery system includes a waste heat boiler 8, and the gas turbine 5 is connected to the waste heat boiler 8. The heat generated by the gas turbine 5 generates steam 10 through the waste heat boiler 8. The steam 10 is provided to the desorption tower 15 in the carbon capture system on the one hand to heat the absorbent for desorption and regeneration, and is provided to the steam turbine 18 of the carbon dioxide refining system to drive the carbon dioxide compressor unit on the other hand. The gas coming out of the waste heat boiler 8 enters the carbon capture system after heat exchange and cooling in the heat exchange gasifier 11.

[0062] In this embodiment, Figure 3 As shown, the carbon capture system consists of an alkali washing desulfurization tower (i.e., a pretreatment tower 12), an absorption tower 13, and a desorption tower 15. The pretreatment tower 12 is connected to a heat exchange gasifier 11. The gas discharged from the waste heat boiler 8 enters the pretreatment tower 12 after heat exchange in the heat exchange gasifier 11. The carbon capture system captures and concentrates low-concentration carbon dioxide into a higher-concentration carbon dioxide gas through alkali washing desulfurization, absorption, and desorption processes. The desorption tower 15 is connected to a centrifugal compressor 19 of a carbon dioxide refining system, and a higher-concentration carbon dioxide gas enters the centrifugal compressor 19. The desorption tower 15 is also connected to a bottom reboiler 16. The steam 10 is heat-exchanged through the bottom reboiler 16 to heat the absorbent of the desorption tower 15 to achieve desorption and regeneration. The steam 10 gas after heat exchange is transported back to the waste heat boiler 8, and boiler feed water 9 is introduced into the waste heat boiler 8. The heat of the desorption tower 15 is provided by the steam 10 generated by the waste heat boiler 8, which makes full use of the heat of the entire system, saves external energy consumption, and achieves low-cost operation.

[0063] In this embodiment, Figure 5As shown, the carbon dioxide refining system consists of three parts: a steam turbine compressor unit, a purification tower 24, and a distillation tower 30, specifically including a steam turbine compressor unit, a purification tower 24, a precooler 26, a heat exchanger 27, a liquefier 28, a refrigeration system 29, a distillation tower 30 and a storage tank 31 connected in sequence. The steam turbine compressor unit consists of three units: a steam turbine 18, a centrifugal compressor 19, and an electric generator II20. The steam turbine 18 is connected to the centrifugal compressor 19 and the electric generator II20. The centrifugal compressor 19 is connected to the desorption tower 15. The steam 10 is input into the steam turbine 18 to generate mechanical energy to drive the centrifugal compressor 19 to achieve the compression of a higher concentration of carbon dioxide gas, and compress the carbon dioxide to 2.0-3.0MpaG. The insufficient energy can be supplemented by the power generation of the energy recovery system, or the excess steam 10 after meeting the needs of the centrifugal compressor 19 can be used to generate electricity through the electric generator II20 and provided to other electrical equipment. The whole system is flexible and adjustable. The start-up of the centrifugal compressor 19 can also be achieved by external power supply. The centrifugal compressor 19 is connected to the purification tower 24, and the gaseous carbon dioxide II23 (pressurized gas) compressed by the centrifugal compressor 19 enters the purification tower 24, that is, the carbon dioxide refining system converts the gaseous carbon dioxide 23 into high-purity liquid carbon dioxide through compression, purification, liquefaction, and distillation and stores it in the storage tank 31. A heat exchanger 27 is also provided between the purification tower 24 and the liquefier 28, and the purification tower 24 is connected to a heater 25, and the heater 25 is connected to the heat exchanger 27. The two low-temperature gases (under pressure) of the top gas of the distillation tower 30 and the exhaust gas of the top of the storage tank 31 are recovered. The exhaust gas of the top of the distillation tower 30 and the exhaust gas of the top of the storage tank 31 are two pressurized gases with a temperature below zero. The two gases with a temperature below zero are recovered and heat-exchanged with the gas discharged from the purification tower 24 through the heat exchanger 27 to recover the cold. That is, a part of the exhaust gas of the top of the distillation tower 30 and the exhaust gas of the top of the storage tank 31 is heated by the heater 25 and used for the regeneration of the purification tower 24. The regenerated gas passes through the pre-cooler 26 and merges with the remaining gas in the heat exchanger 27. After the merger, the carbon dioxide gas exceeding 1.0Mpa is driven by the tail gas turbine 21 to drive the generator III22 to recover the pressure energy, and then returns to the front of the absorption tower 13 of the carbon capture system, which not only effectively recovers energy, but also recovers carbon dioxide, thereby improving the carbon capture recovery rate.

[0064] In this embodiment, Figure 2As shown, the carbon dioxide gasification system consists of a booster pump 32, a precooler 26, and a heat exchange gasifier 11. The booster pump 32 is connected to the storage tank 31 and the precooler 26 on both sides, and the precooler 26 is connected to the heat exchange gasifier 11. Carbon dioxide carbon conversion generally requires high-pressure and high-purity gaseous carbon dioxide. First, the liquid carbon dioxide is pressurized to the required pressure by the booster pump 32, and heat is exchanged with the normal temperature gas after passing through the purification tower 24 in the precooler 26 to recover the cold, and then the heat exchange gasifier 11 exchanges heat with the gas discharged from the waste heat boiler 8 for gasification, and the liquid carbon dioxide is gasified into a high-purity gas and enters the carbon conversion system 35. It not only reduces the temperature of the gas entering the alkali washing desulfurization tower, but also gasifies the liquid carbon dioxide into gas, making full use of the energy in the system and greatly reducing system consumption.

[0065] In this embodiment, Figure 6 As shown, the carbon conversion system 35 is used to convert high-purity carbon dioxide gas and hydrogen 33 and other hydrogen-containing substances into high-value-added chemicals and fuels 36 through thermal catalysis, electrocatalysis, photocatalysis and other conversion pathways and methods. In this embodiment, the gaseous carbon dioxide product 34 and hydrogen 33 after heat exchange in the heat exchange gasifier 11 are used to generate chemicals such as methanol.

[0066] In the present invention, the gas to be treated 1 is pressurized by the compressor 3 and enters the gas turbine 5, and the gas and the air compressed by the compressor 6 are oxidized and burned in the combustion chamber of the gas turbine. The high-temperature and high-pressure gas generated drives the compressor 6 to compress the air 2, and the excess mechanical energy generated by the gas turbine 5 drives the electric generator 17 to generate electricity, and the generated electricity is used to power the motor 4 of the compressor. The high-temperature gas of the gas turbine 5 generates steam 10 through the waste heat boiler 8 and is provided to the desorption tower 15 in the carbon capture system, and the absorbent is heated for desorption and regeneration, and is provided to the steam turbine 18 of the carbon dioxide refining system to drive the carbon dioxide compressor unit. The gas from the waste heat boiler 8 enters the carbon capture system after heat exchange and cooling. The low-concentration carbon dioxide is captured and concentrated into a higher-concentration carbon dioxide gas through the alkaline washing desulfurization, absorption, and desorption process. The higher-concentration carbon dioxide gas enters the carbon dioxide refining system, and is compressed, purified, liquefied, and distilled to become high-purity liquid carbon dioxide and stored in the storage tank 31, and then passes through the gasification system to become high-purity gas. The high-purity carbon dioxide is further converted into high-value-added chemicals and fuels 36 through reactions with hydrogen and the like. The gas to be treated 1 is treated by the gas oxidation power generation and carbon capture comprehensive utilization method of the present invention, so that the pressure and heat of all gases in the system are fully recovered and utilized, and the exhaust gas fully meets the environmental protection standards. While saving energy and reducing emissions, carbon capture and recycling of refined carbon dioxide is carried out, and further converted into chemicals such as methanol and fuel 36, etc., which is an important carbon emission reduction technology.

[0067] Example 2

[0068] Based on Example 1, the present invention further provides a gas oxidation treatment and carbon capture comprehensive utilization device, which is different from Example 1 in that: Figure 4 As shown, phase change is used in the carbon capture system to concentrate carbon dioxide.

[0069] Specifically, the carbon capture system consists of an alkaline desulfurization tower (i.e., a pretreatment tower 12), an absorption tower 13, a liquid storage tank 38, a phase change separation tank 39 and a desorption tower 15. The pretreatment tower 12 is connected to the heat exchange gasifier 11. The gas discharged from the waste heat boiler 8 enters the pretreatment tower 12 after heat exchange in the heat exchange gasifier 11. The carbon capture system captures low-concentration carbon dioxide and concentrates it into a higher-concentration carbon dioxide gas through alkaline desulfurization, absorption, phase change, separation, and desorption processes.

[0070] The gas coming out of the absorption tower 13 is directly discharged as the exhaust gas 14 through the first gas-liquid separation tank 37. Out; Absorption tower 13 bottom The absorbed liquid enters the phase change separation tank 39 through the first heat exchanger 41 and is After the separation, the lower liquid phase rich in carbon dioxide enters the desorption tower 15, and the upper liquid phase without carbon dioxide directly enters the liquid storage tank 38; after the lower liquid phase desorbs carbon dioxide, it exchanges heat with the absorption liquid flowing out of the absorption tower 13 through the first heat exchanger 41 and returns to the liquid storage tank 38. After the top gas of the desorption tower 15 enters the second gas-liquid separation tank 40, it is discharged as gaseous carbon dioxide I17 (slightly positive pressure gas) and enters the centrifugal compressor 19 to power the electric generator II 20 for power generation; the separated liquid returns to the desorption tower 15.

[0071] The desorption tower 15 is also connected to a tower bottom reboiler 16. The steam 10 is heat exchanged through the tower bottom reboiler 16 to heat the absorbent in the desorption tower 15 to achieve desorption and regeneration. The steam 10 after heat exchange is transported back to the waste heat boiler 8, and boiler feed water 9 is introduced into the waste heat boiler 8. The heat of the desorption tower 15 is provided by the steam 10 generated by the waste heat boiler 8, which makes full use of the heat of the entire system, saves external energy consumption, and achieves low-cost operation.

[0072] Example 3

[0073] On the basis of Examples 1 and 2, the present invention further provides a method for gas oxidation treatment and carbon capture comprehensive utilization, which is a method for combustible gas oxidation treatment and carbon capture comprehensive utilization, and the method adopts a combustible gas oxidation treatment and carbon capture comprehensive utilization device, and comprises the following steps:

[0074] (1) The gas to be treated 1 (combustible gas) is pressurized by the compressor 3 and enters the gas turbine 5. It undergoes an oxidation combustion reaction with the air 2 compressed by the compressor 6 in the combustion chamber of the gas turbine. The high-temperature and high-pressure gas generated drives the compressor 6 to compress the air 2. The excess mechanical energy generated by the gas turbine 5 drives the electric generator 1 7 to generate electricity. The generated electricity is used to power the motor 4 of the compressor. The gas to be treated 1 can also be a mixed gas containing VOCs gas and combustible gas. That is, when the combustion value of the VOCs gas is not enough for combustion, the combustion value is increased by the combustible gas. The combustion value of the two gases after being mixed and pressurized should meet the combustion standard in the combustion chamber of the gas turbine.

[0075] (2) The high-temperature gas from the gas turbine 5 is passed through the waste heat boiler 8 to generate steam 10. The gas from the waste heat boiler 8 is cooled by the heat exchanger gasifier 11 and enters the carbon capture system. The gas passes through the pre-processor 12, the absorption tower 13 and the desorption tower 15 in sequence, that is, the low-concentration carbon dioxide is captured and concentrated into a higher-concentration carbon dioxide gas through the alkaline washing desulfurization, absorption and desorption process. The higher-concentration carbon dioxide gas enters the carbon dioxide refining system and passes through the centrifugal compressor 19, the purification tower 24, the liquefier 28, the refrigeration system 29, the distillation tower 30 and the storage tank 31 in sequence, that is, the higher-concentration carbon dioxide gas is converted into high-purity liquid carbon dioxide through compression, purification, liquefaction and distillation and stored in the storage tank 31. The liquid carbon dioxide is converted into high-purity carbon dioxide gas through heat exchange in the pre-cooler 26 and the heat exchanger gasifier 11. The high-purity carbon dioxide is further converted into high-value-added chemicals and fuels 36 through the carbon conversion system by reacting with hydrogen and the like.

[0076] (3) The heat generated by the high-temperature reaction is provided to the desorption tower 15 in the carbon capture system through the waste heat boiler 8 to generate steam 10 for heating the absorbent for desorption and regeneration, and provided to the steam turbine 18 of the carbon dioxide refining system to drive the centrifugal compressor 19 to compress the carbon dioxide. The excess steam can also be used to drive the electric generator II 20 through the steam turbine 18 to generate electricity and be provided to other electrical equipment in the system.

[0077] (4) The distillation tower 30 and the storage tank 31 are pressure vessels and need to be exhausted. The two low-temperature gases (pressurized low-temperature carbon dioxide gases) from the top of the distillation tower 30 and the top of the storage tank 31 are heat-exchanged with the gas discharged from the purification tower 24 to recover cold energy. A portion of the gas is heated by the heater 25 and used for regeneration of the purification tower 24. The regenerated gas is combined with the remaining gas. The carbon dioxide gas exceeding 1.0 MPa after the combination is recovered through the tail gas turbine 21 for pressure energy, and then returned to the carbon capture system to improve the carbon capture recovery rate.

[0078] Example 4

[0079] Specifically, the device of the present invention is used to process a stream of natural gas (7400Nm 3 / h), is pressurized to 2.8Mpa by compressor 3, and enters into combustion chamber of gas turbine 5 together with air 2 of 2.5Mpa for combustion. The power generation capacity of gas turbine 5 is 24.25MW, and the power generation capacity of steam turbine 18 is 9.87MW. The carbon dioxide content of tail gas produced is about 3%. About 90,000 tons of liquid carbon dioxide can be recovered annually through carbon capture and refining system, and about 60,000 tons of methanol can be produced further through carbon conversion system.

[0080]

[0081]

[0082] The above embodiments are only preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the above embodiments, a person of ordinary skill in the art should understand that any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A gas oxidation treatment and carbon capture comprehensive utilization device, comprising: Gas oxidation power generation system, heat recovery system, carbon capture system, carbon dioxide refining system, energy recovery system, carbon dioxide gasification system, carbon conversion system and heat exchange system; characterized in that: The gas oxidation power generation system is connected to the heat recovery system and the carbon dioxide refining system to recover the energy of the high-temperature gas generated by oxidation combustion to power the electric generator and the motor of the compressor unit; The gas oxidation power generation system and the heat recovery system are connected to the carbon capture system and the carbon dioxide refining system. The gas discharged after the reaction enters the carbon capture system after heat exchange through the heat exchange system, and the steam generated after the reaction is respectively input into the carbon capture system and the carbon dioxide refining system; The carbon capture system is connected to a carbon dioxide refining system, and is used to generate a relatively high concentration of carbon dioxide gas and input it into the carbon dioxide refining system. The carbon dioxide refining system is used to generate a high concentration of liquid carbon dioxide from the relatively high concentration of carbon dioxide gas and store it; The energy recovery system is connected to the carbon dioxide refining system and is used to recover the pressure energy of the exhaust gas from the top of the distillation tower of the carbon dioxide refining system and the exhaust gas from the top of the storage tank through the tail gas turbine to supply power to the electric generator and the motor of the compressor unit; The carbon dioxide gasification system is connected to the carbon dioxide refining system and the carbon conversion system, and is used to convert the stored high-concentration liquid carbon dioxide into high-concentration carbon dioxide gas through the heat exchange system, and input it into the carbon conversion system to generate chemicals and fuels.

2. The gas oxidation treatment and carbon capture comprehensive utilization device according to claim 1, characterized in that: The gas oxidation treatment power generation system consists of a compressor unit and a gas turbine generator unit. The compressor unit includes a compressor and a motor. The gas turbine generator unit includes a gas turbine, a compressor and an electric generator I. The compressor pressurizes the gas to be treated and an oxidation combustion reaction occurs with the air compressed by the compressor in the combustion chamber of the gas turbine. The high-temperature and high-pressure gas generated drives the electric generator I to generate electricity, and the generated electricity is used to power the motor of the compressor unit.

3. The gas oxidation treatment and carbon capture comprehensive utilization device according to claim 2, characterized in that: The gas to be treated contains at least combustible gas, and the combustible gas is one or more streams of hydrocarbon, carbon monoxide or hydrogen gas.

4. The gas oxidation treatment and carbon capture comprehensive utilization device according to claim 3, characterized in that: When the gas to be treated contains VOCs gas, the combustion value of the combustible gas after being mixed and pressurized with the VOCs gas should meet the requirements for combustion in the combustion chamber of a gas turbine.

5. The gas oxidation treatment and carbon capture comprehensive utilization device according to claim 2, characterized in that: The heat recovery system is a waste heat boiler. The high-temperature gas exhausted by the gas turbine generates steam through the waste heat boiler and then enters the carbon capture system and the carbon dioxide refining system. The gas exhausted from the waste heat boiler enters the heat exchange system for heat exchange.

6. The gas oxidation treatment and carbon capture comprehensive utilization device according to claim 1, characterized in that: The carbon dioxide refining system includes a steam turbine compressor unit, a purification tower, a liquefier, a refrigeration system, a distillation tower and a storage tank which are connected in sequence. Through the compression, purification, liquefaction and distillation processes, the captured carbon dioxide gas with a higher concentration is further purified and liquefied to obtain high-concentration liquid carbon dioxide and stored in the storage tank; the steam turbine compressor unit is a carbon dioxide compressor unit, which is connected to the carbon capture system and is used to compress the higher-concentration carbon dioxide gas generated by the carbon capture system; the purification tower is connected to the steam turbine compressor unit and is used to purify the compressed carbon dioxide gas. The liquefaction process uses a liquefier and a refrigeration system, and the distillation process uses a distillation tower.

7. The gas oxidation treatment and carbon capture comprehensive utilization device according to claim 1, characterized in that: The energy recovery system includes a heat exchange system and an exhaust gas turbine unit. The exhaust gas from the top of the distillation tower and the exhaust gas from the top of the storage tank are two streams of pressurized carbon dioxide gases with a temperature below zero. The two gases with a temperature below zero are recovered and exchanged with the gas discharged from the purification tower through a heat exchanger to recover the cold. A part of the gas is heated by a heater and used for regeneration of the purification tower. The regenerated gas is merged with the remaining gas. The carbon dioxide gas exceeding 1.0MPa after the merger is returned to the carbon capture system after recovering energy through the energy recovery system.

8. The gas oxidation treatment and carbon capture comprehensive utilization device according to claim 1, characterized in that: The carbon capture system includes three processes of alkaline washing desulfurization, absorption and desorption to capture low-concentration carbon dioxide and concentrate it into higher-concentration carbon dioxide gas, wherein the alkaline washing desulfurization process adopts a pretreatment tower, the absorption process adopts an absorption tower, and the desorption process adopts a desorption tower; the pretreatment tower, the absorption tower and the desorption tower are connected in sequence; the heat of the desorption tower is provided by the steam generated by the heat recovery system, wherein the desorption tower is connected to a bottom reboiler, and the steam is heat-exchanged through the bottom reboiler to heat the absorbent to achieve desorption regeneration, and the condensed water after heat exchange is transported back to the heat recovery system.

9. The gas oxidation treatment and carbon capture comprehensive utilization device according to claim 8, characterized in that: The carbon capture system also includes a phase change process between the absorption process and the desorption process. The phase change process uses a liquid storage tank and a phase change separation tank. The pretreatment tower, the absorption tower, the liquid storage tank, the phase change separation tank and the desorption tower are connected in sequence. The absorption liquid from the absorption tower enters the phase change separation tank through the first heat exchanger. After phase change separation, the lower liquid phase rich in carbon dioxide enters the desorption tower, and the upper liquid phase without carbon dioxide directly enters the liquid storage tank. After the lower liquid phase desorbs carbon dioxide, it exchanges heat with the solution from the absorption tower through the first heat exchanger and then returns to the liquid storage tank.

10. A method for gas oxidation treatment and carbon capture comprehensive utilization, characterized in that: The method is carried out using the gas oxidation treatment and carbon capture comprehensive utilization device according to any one of claims 1 to 9, and comprises the following steps: S1. The gas to be treated is pressurized by the compressor and enters the gas turbine. It undergoes oxidation and combustion reaction with the air compressed by the compressor in the combustion chamber of the gas turbine. The high-temperature and high-pressure gas generated drives the compressor to pressurize the air. The excess mechanical energy generated by the gas turbine drives the electric generator I to generate electricity, and the generated electricity is used to power the compressor. S2. The high-temperature gas discharged from the gas turbine generates steam and discharges the gas through the waste heat boiler; S21. The gas discharged from the waste heat boiler is cooled by heat exchange in the heat exchanger gasifier and enters the carbon capture system. The gas passes through the pretreatment tower, absorption tower and desorption tower in sequence, that is, the low-concentration carbon dioxide is captured and concentrated into a higher-concentration carbon dioxide gas through the alkaline washing desulfurization, absorption and desorption process; the higher-concentration carbon dioxide gas enters the carbon dioxide refining system, passes through the centrifugal compressor, purification tower, liquefier, refrigeration system, distillation tower and storage tank in sequence, that is, the higher-concentration carbon dioxide gas is converted into high-concentration liquid carbon dioxide through compression, purification, liquefaction and distillation and stored in the storage tank; when preparing chemicals and fuels, the liquid carbon dioxide in the storage tank is converted into carbon dioxide gas through a pressure pump, a precooler and a heat exchanger gasifier, and the carbon dioxide gas is further converted into chemicals and fuels through a carbon conversion system; S22. A portion of the steam generated by the waste heat boiler is supplied to the desorption tower in the carbon capture system to heat the absorbent for desorption and regeneration, and another portion is supplied to the steam turbine of the carbon dioxide refining system to generate mechanical energy to drive the centrifugal compressor to compress the carbon dioxide. The excess steam can be used to drive the electric generator II through the steam turbine to generate electricity and be supplied to other electrical equipment in the system; S3. The exhaust gas from the top of the distillation tower and the exhaust gas from the top of the storage tank are two streams of pressurized carbon dioxide gases with a temperature below zero degrees. The two streams of carbon dioxide gases with a temperature below zero degrees are heat-exchanged with the gas discharged from the purification tower to recover cold energy. A part of the gas is heated by a heater and used for regeneration of the purification tower. The regenerated gas is combined with the remaining gas. The carbon dioxide gas exceeding 1.0MPa after the combination is returned to the carbon capture system after energy recovery through the energy recovery system.

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