Blast furnace gas pressure swing adsorption carbon dioxide capture coupling compression energy storage system

Abstract

The invention discloses a blast furnace gas pressure swing adsorption carbon dioxide capture coupling compression energy storage system, and belongs to the technical field of adsorption and energy storage. According to the blast furnace gas pressure swing adsorption carbon dioxide capture coupling compression energy storage system, through energy integration, pressure energy and heat energy of blast furnace gas are utilized, and cooperation of CO2 capture and compression energy storage is achieved. Through heat recovery and pressure energy utilization, the overall efficiency of the system is remarkably improved, and the cost is reduced. In addition, the system can flexibly adjust the CO2 capture and energy storage process according to the power grid demand, and the flexibility of the system is improved. The innovative coupling system provided by the invention not only can effectively solve the problem of CO2 emission reduction in the iron and steel industry, but also can provide support for large-scale application of renewable energy sources, and has important theoretical significance and practical application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of adsorption and energy storage, and in particular relates to a blast furnace gas pressure swing adsorption carbon dioxide capture coupled compression energy storage system. Background Art

[0002] Blast furnace gas is a byproduct of the steel production process, which contains a large amount of carbon dioxide (CO2). As the global demand for greenhouse gas emission reduction continues to increase, how to effectively capture and utilize CO2 in blast furnace gas has become an important challenge facing the steel industry. Pressure swing adsorption (PSA) is a widely used gas separation technology. It has been widely used in carbon capture demonstration projects in the petroleum, chemical, natural gas and other industries at home and abroad, and can be used to capture CO2 from blast furnace gas. Pressure swing adsorption carbon capture technology has the advantages of non-corrosive equipment, long adsorbent cycle, simple process, high degree of automation, and good environmental benefits. However, the traditional PSA process faces problems such as high energy consumption, low separation efficiency and large equipment size, which limits the application effect of PSA technology in large-scale CO2 capture.

[0003] With the transformation of the global energy structure and the increasing proportion of renewable energy, the power system is facing new challenges. The intermittent and volatile characteristics of renewable energy have put forward higher requirements on the stability and reliability of the power grid. Compressed energy storage technology can effectively smooth the output fluctuations of renewable energy, improve the stability and reliability of the power grid, and show broad application prospects in power grid peak regulation, renewable energy grid connection, distributed energy systems, etc. In the industrial field, compressed energy storage can also be combined with waste heat utilization, residual pressure recovery and other technologies to further improve energy utilization efficiency. Compressed energy storage technology still faces some challenges in practical applications, mainly including the need to improve system efficiency, further reduce costs, and coordinated integration with other energy technologies. Therefore, the development of innovative compressed energy storage systems, especially integrated systems that can be combined with other energy utilization processes, has become one of the key directions of current research.

[0004] The innovative solution of combining compressed energy storage technology with industrial processes (such as blast furnace gas treatment and CO2 capture) can provide a new way for industrial energy conservation and emission reduction while solving the limitations of compressed energy storage itself, which has important practical significance and application value. Compressed air energy storage (CAES) is a large-scale energy storage technology with great potential, but it also has problems such as low energy density, limited system efficiency and site selection restrictions, which need further optimization and improvement. Combining CO2 capture with compressed energy storage technology is expected to achieve synergistic effects and improve the overall efficiency of the system. Summary of the invention

[0005] The object of the present invention is to provide a system for blast furnace gas pressure swing adsorption carbon dioxide capture coupled with compression energy storage and an operation method of the system. The system for blast furnace gas pressure swing adsorption CO2 capture coupled with compression energy storage proposed in the present invention has significant advantages. The system realizes the synergy of CO2 capture and compression energy storage by utilizing the pressure energy and thermal energy of blast furnace gas through energy integration. Through heat recovery and pressure energy utilization, the overall efficiency of the system is significantly improved and the cost is reduced. In addition, the system can flexibly adjust the CO2 capture and energy storage process according to the needs of the power grid, thereby improving the flexibility of the system. The innovative coupling system provided by the present invention can not only effectively solve the problem of CO2 emission reduction in the steel industry, but also provide support for the large-scale application of renewable energy, which has important theoretical significance and practical application value.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One of the technical solutions of the present invention is to provide a system for blast furnace gas pressure swing adsorption carbon dioxide capture coupled with compression energy storage, comprising: a dust removal unit, a dry desulfurization device, a temperature swing adsorption (TSA) dehydration device, a carbon dioxide PSA adsorption device 1, a compressor 1, a carbon dioxide PSA adsorption device 2, a compressor 2, a heat exchanger 2, a heat exchanger 3, a carbon dioxide high-pressure storage tank, a heat exchanger 4, an expansion power generation device and a heat exchanger 5 connected in sequence;

[0008] The dust removal unit is connected to the interlayer of the TSA dehydration device, and a stop valve 1 is provided between them;

[0009] A stop valve 2 is provided between the dust removal unit and the dry desulfurization device;

[0010] A stop valve 3+heat exchanger 1 and a stop valve 4 are provided in parallel between the gas outlet of the dry desulfurization device and the gas inlet of the TSA dehydration device;

[0011] A power generation device is provided between the gas outlet of the TSA dehydration device and the gas inlet of the dry desulfurization device;

[0012] The gas outlet of the carbon dioxide PSA adsorption device 1 is connected to the heat exchanger 2, and the heat exchanger 2 is connected to the blast furnace;

[0013] The gas outlet of the carbon dioxide PSA adsorption device 2 is connected to the gas inlet of the carbon dioxide PSA adsorption device 1;

[0014] A stop valve 8 is provided between the heat exchanger 3 and the high-pressure storage tank;

[0015] The gas outlet of the heat exchanger 3 is connected to the carbon dioxide liquefaction storage device, and a stop valve 7 is provided between them;

[0016] A stop valve 9 is provided between the carbon dioxide high-pressure storage tank and the heat exchanger 4;

[0017] The outlet gas of the expansion power generation device also passes through the heat exchanger 4 before entering the heat exchanger 5;

[0018] The gas outlet of the heat exchanger 5 is connected to the gas inlet of the carbon dioxide PSA adsorption device 2 .

[0019] Preferably, the dust removal unit comprises a gravity dust removal device and a bag dust removal device which are arranged in sequence.

[0020] Preferably, the power generation device between the gas outlet of the TSA dehydration device and the gas inlet of the dry desulfurization device is a blast furnace gas residual pressure turbine power generation device (TRT).

[0021] The second technical solution of the present invention is to provide a method for operating the above-mentioned blast furnace gas pressure swing adsorption carbon dioxide capture coupled compression energy storage system, comprising the following steps:

[0022] During the low electricity consumption period, carbon dioxide is compressed and stored. At this stage, stop valve 2, stop valve 3 and stop valve 8 are opened, and stop valve 1, stop valve 4, stop valve 7 and stop valve 9 are closed; the blast furnace gas that has been dedusted by the dust removal unit is first desulfurized by the dry desulfurization device, and then enters the TSA dehydration device through the heat exchanger 1 for dehydration; then carbon dioxide is adsorbed by the carbon dioxide PSA adsorption device 1, and the exhaust gas returns to the blast furnace after passing through the heat exchanger 2. The carbon dioxide desorbed by the carbon dioxide PSA adsorption device 1 passes through the compressor 1 and enters the carbon dioxide PSA adsorption device 2 to adsorb carbon dioxide. The exhaust gas enters the carbon dioxide PSA adsorption device 1, and the carbon dioxide desorbed by the carbon dioxide PSA adsorption device 2 passes through the compressor 2, the heat exchanger 2 and the heat exchanger 3 and is compressed and stored in the high-pressure storage tank;

[0023] During peak hours of electricity consumption, the compressed and stored carbon dioxide is expanded to generate electricity and then concentrated and liquefied for storage. At this stage, stop valves 1, 4, 7 and 9 are opened, and stop valves 2, 3 and 8 are closed. The blast furnace gas that has been dedusted by the dust removal unit first passes through the interlayer of the TSA dehydration device to heat and regenerate the adsorbent, then enters the dry desulfurization device for desulfurization after generating electricity through the power generation device, and then is dehydrated through the TSA dehydration device; then enters the carbon dioxide PSA adsorption device 1 to adsorb carbon dioxide, and the exhaust gas returns to the blast furnace after passing through the heat exchanger 2. The carbon dioxide PSA adsorption The carbon dioxide desorbed after adsorption by device 1 enters the carbon dioxide PSA adsorption device 2 through the compressor 1 to adsorb carbon dioxide, and the exhaust gas enters the carbon dioxide PSA adsorption device 1. The carbon dioxide desorbed after adsorption by the carbon dioxide PSA adsorption device 2 is purged and then enters the carbon dioxide liquefaction storage device for liquefied storage after passing through the compressor 2, the heat exchanger 2 and the heat exchanger 3; the purge gas used for purge desorption is obtained by the high-pressure carbon dioxide stored in the high-pressure storage tank entering the expansion power generation device through the heat exchanger 4 for expansion power generation, and then passing through the heat exchanger 4 and the heat exchanger 5.

[0024] The carbon dioxide PSA adsorption device 1 and the carbon dioxide PSA adsorption device 2 of the present invention contain a plurality of adsorption towers, each of which operates independently and can adsorb and desorb carbon dioxide at the same time.

[0025] The system of blast furnace gas pressure swing adsorption carbon dioxide capture coupled compression energy storage using the present invention:

[0026] From the perspective of energy storage, under the same conditions, due to the larger molecular mass of CO2 (44g / mol, which is larger than the 28g / mol of air), the energy density of CO2 under high pressure is higher than that of air. Compared with compressed air energy storage, the use of high-concentration CO2 enriched by blast furnace gas for compressed energy storage can increase the energy storage density by 10% to 20%, from 30kWh / m 3 To 33~36kWh / m 3 ;

[0027] For the pressure swing adsorption carbon capture process, the adsorption capture process is mainly electricity consumption, accounting for more than 90%. By utilizing the excess pressure of blast furnace gas during low electricity consumption, the raw gas compression energy consumption of PSA1 can be saved. It is expected that the electricity consumption of the pressure swing adsorption carbon capture process can be reduced by 20% to 30%, and the operating power of the PSA system can be reduced from 100kW to 70kW to 80kW. Compared with not utilizing the excess pressure of blast furnace gas, when the excess pressure of blast furnace gas is not utilized, the capture power consumption of one ton of CO2 is 250kW·h. After utilizing the excess pressure, the capture power consumption of one ton of CO2 is reduced to 175kW·h to 200kW·h, and the corresponding electricity cost is reduced by 20% to 30%.

[0028] The beneficial technical effects of the present invention are as follows:

[0029] (1) The present invention uses blast furnace gas as raw material and pressure swing adsorption as CO2 capture technology. By coupling compression energy storage, the capture purity and recovery rate of CO2 are significantly improved, and high-efficiency, low-cost cyclic capture and storage of CO2 in blast furnace gas can be achieved.

[0030] (2) The present invention uses the relatively high purity CO2 obtained by pressure swing adsorption capture of blast furnace gas as the working fluid for energy storage, which can achieve high-density storage and efficient release of CO2 in blast furnace gas, while increasing the circulation flow rate and energy storage density of blast furnace gas energy storage, while reducing the power consumption and electricity cost of pressure swing adsorption, thereby reducing the cost of compressed energy storage and pressure swing adsorption CO2 capture.

[0031] (3) The present invention makes full use of the high temperature and high pressure emission characteristics of blast furnace gas, and regenerates the dehydration adsorbent by heating the TSA device with high temperature gas, thereby saving the additional energy consumption required for TSA dehydration. At the same time, the heat network return water and the gas inside the system are used as the heat exchange medium, which efficiently utilizes the energy generated in the system and reduces the dependence on external energy during the circulation process, which is beneficial to reducing the energy consumption of the system and has good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the operation of the blast furnace gas pressure swing adsorption CO2 capture coupled compression energy storage system in Example 1 of the present invention.

[0033] Figure 2 Schematic diagram of the TSA dehydration device in Example 1 of the present invention. DETAILED DESCRIPTION

[0034] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0035] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0036] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0037] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0038] Example 1

[0039] After being discharged from the top of the blast furnace, the blast furnace gas is dedusted by gravity dust removal and bag dust removal. After dedusting, the pressure is 0.2MPa and the temperature is 130-150℃. When the grid load is at a low point, it is the CO2 capture compression energy storage stage: in this stage, the stop valve 2 is opened and the stop valve 1 is closed. After the dedusting blast furnace gas is dry desulfurized, it is cooled by the stop valve 3 using the low-temperature return water of the heat network water supply port 1, and then used Figure 2 The coal gas dehydrated by the TSA dehydration tower is connected to the gas inlet end of the pressure swing adsorption device 1; at this time, the stop valve 5 is opened and the stop valve 6 is closed, and the heat exchanger 1 is used for heat exchange and heating; the high-pressure gas after desulfurization, cooling and drying enters the PSA1 device to improve the CO2 recovery rate, and the adsorbed tail gas (waste gas 1) is preheated by the heat exchanger 2 and refluxed to the blast furnace, and the product gas is compressed by the compressor 1 and enters the PSA2 for further concentration. The adsorbed tail gas (waste gas 2) of PSA2 is refluxed to the PSA1 air inlet to further improve the CO2 recovery rate. The product gas (higher CO2 purity) desorbed by PSA2 is pressurized by the compressor 2 and cooled by the heat exchanger 2 and the heat exchanger 3, and then enters the high-pressure storage tank for storage through the stop valve 8.

[0040] When the grid load is at its peak, it is the CO2 expansion power generation and concentration stage: in this stage, shut-off valve 1 is opened and shut-off valve 2 is closed, and high-temperature coal gas is used as a heat source to enter Figure 2The interlayer of the TSA dehydration tower 1 heats the adsorbent to achieve regeneration, and then dry desulfurization is carried out after TRT power generation, which reduces the power consumption during the peak load of the power grid and thus reduces the comprehensive cost of CO2 capture; at this time, the stop valve 4 and the stop valve 6 are opened, and the stop valve 3 and the stop valve 5 are closed. The desulfurized coal gas is directly used to capture CO2 after dehydration, and the return water at the heat network return port 1 is heat exchanged with the high-temperature CO2 after expansion power generation for heating and heat supply; the coal gas after TRT is low-pressure coal gas, and the CO2 capture purity is relatively high at this time. The PSA1 adsorbed tail gas (waste gas 1) is preheated by the heat exchanger 2 and then refluxed to the blast furnace. The product gas is compressed by the compressor 1 and then enters the PSA2 for further concentration. The adsorbed tail gas (waste gas 2) of PSA2 is refluxed to the air inlet of PSA1 to further improve the CO2 recovery rate, and at the same time, the use The exhaust gas from expansion power generation is used as a purge gas to further increase the CO2 concentration and obtain high-purity CO2 for liquefaction, storage and utilization. The product gas desorbed from PSA2 is purged with CO2 (high-purity CO2), pressurized by compressor 2 and cooled by heat exchanger 2 and heat exchanger 3, and then further compressed, liquefied, stored and utilized through stop valve 7; when the grid load is at its peak, stop valve 9 is opened, and the CO2 stored when the grid load is at its low point is used for expansion power generation. Before expansion power generation, the exhaust gas from expansion power generation is first passed through heat exchanger 4 for heat exchange to further improve the power generation efficiency before entering the expander for power generation; the expanded exhaust gas is cooled by the low-temperature CO2 gas passing through heat exchanger 4, and then passed through heat exchanger 5 to be further cooled using the return water from the heat network return water port 1, and then is passed into PSA2 as a purge gas to further improve the purity of the CO2 product gas.

[0041] The schematic diagram of the operation of the blast furnace gas pressure swing adsorption CO2 capture coupled compression energy storage system in Example 1 is shown in Figure 1 .

[0042] The system using the blast furnace gas pressure swing adsorption carbon dioxide capture coupled with compression energy storage of Example 1:

[0043] From the perspective of energy storage, under the same conditions, compared with compressed air energy storage, the use of high-concentration CO2 enriched by blast furnace gas for compressed energy storage can increase the energy storage density by 15%, from 30kWh / m 3 Up to 34.5kWh / m 3 ;

[0044] For the pressure swing adsorption carbon capture process, the adsorption capture process is mainly electricity consumption, accounting for more than 90%. By utilizing the excess pressure of blast furnace gas during low electricity consumption, the raw gas compression energy consumption of PSA1 can be saved. It is expected that the electricity consumption of the pressure swing adsorption carbon capture process can be reduced by 20%, and the operating power of the PSA system can be reduced from 100kW to 80kW. Compared with not utilizing the excess pressure of blast furnace gas, when not utilizing the excess pressure of blast furnace gas, the capture power consumption of one ton of CO2 is 250kW·h. After utilizing the excess pressure, the capture power consumption of one ton of CO2 is reduced to 200kW·h, and the corresponding electricity cost is reduced by 20%.

[0045] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A blast furnace gas pressure swing adsorption carbon dioxide capture coupled compression energy storage system, characterized in that: include: A dust removal unit, a dry desulfurization device, a TSA dehydration device, a carbon dioxide PSA adsorption device 1, a compressor 1, a carbon dioxide PSA adsorption device 2, a compressor 2, a heat exchanger 2, a heat exchanger 3, a carbon dioxide high-pressure storage tank, a heat exchanger 4, an expansion power generation device and a heat exchanger 5 are connected in sequence; The dust removal unit is connected to the interlayer of the TSA dehydration device, and a stop valve 1 is provided between them; A stop valve 2 is provided between the dust removal unit and the dry desulfurization device; A stop valve 3+heat exchanger 1 and a stop valve 4 are provided in parallel between the gas outlet of the dry desulfurization device and the gas inlet of the TSA dehydration device; A power generation device is provided between the gas outlet of the TSA dehydration device and the gas inlet of the dry desulfurization device; The gas outlet of the carbon dioxide PSA adsorption device 1 is connected to the heat exchanger 2, and the heat exchanger 2 is connected to the blast furnace; The gas outlet of the carbon dioxide PSA adsorption device 2 is connected to the gas inlet of the carbon dioxide PSA adsorption device 1; A stop valve 8 is provided between the heat exchanger 3 and the high-pressure storage tank; The gas outlet of the heat exchanger 3 is connected to the carbon dioxide liquefaction storage device, and a stop valve 7 is provided between them; A stop valve 9 is provided between the carbon dioxide high-pressure storage tank and the heat exchanger 4; The outlet gas of the expansion power generation device also passes through the heat exchanger 4 before entering the heat exchanger 5; The gas outlet of the heat exchanger 5 is connected to the gas inlet of the carbon dioxide PSA adsorption device 2 .

2. The blast furnace gas pressure swing adsorption carbon dioxide capture coupled compression energy storage system according to claim 1 is characterized in that: The dust removal unit comprises a gravity dust removal device and a bag dust removal device which are arranged in sequence.

3. The blast furnace gas pressure swing adsorption carbon dioxide capture coupled compression energy storage system according to claim 1 is characterized in that: The power generation device between the gas outlet of the TSA dehydration device and the gas inlet of the dry desulfurization device is a blast furnace gas waste pressure turbine power generation device.

4. An operating method of the blast furnace gas pressure swing adsorption carbon dioxide capture coupled compression energy storage system according to any one of claims 1 to 3, characterized in that: The following steps are involved: During the low electricity consumption period, carbon dioxide is compressed and stored. At this stage, stop valve 2, stop valve 3 and stop valve 8 are opened, and stop valve 1, stop valve 4, stop valve 7 and stop valve 9 are closed; the blast furnace gas that has been dedusted by the dust removal unit is first desulfurized by the dry desulfurization device, and then enters the TSA dehydration device through the heat exchanger 1 for dehydration; then carbon dioxide is adsorbed by the carbon dioxide PSA adsorption device 1, and the exhaust gas returns to the blast furnace after passing through the heat exchanger 2. The carbon dioxide desorbed by the carbon dioxide PSA adsorption device 1 passes through the compressor 1 and enters the carbon dioxide PSA adsorption device 2 to adsorb carbon dioxide. The exhaust gas enters the carbon dioxide PSA adsorption device 1, and the carbon dioxide desorbed by the carbon dioxide PSA adsorption device 2 passes through the compressor 2, the heat exchanger 2 and the heat exchanger 3 and is compressed and stored in the high-pressure storage tank; During peak hours of electricity consumption, the compressed and stored carbon dioxide is expanded to generate electricity and then concentrated and liquefied for storage. At this stage, stop valves 1, 4, 7 and 9 are opened, and stop valves 2, 3 and 8 are closed. The blast furnace gas that has been dedusted by the dust removal unit first passes through the interlayer of the TSA dehydration device to heat and regenerate the adsorbent, then enters the dry desulfurization device for desulfurization after generating electricity through the power generation device, and then is dehydrated through the TSA dehydration device; then enters the carbon dioxide PSA adsorption device 1 to adsorb carbon dioxide, and the exhaust gas returns to the blast furnace after passing through the heat exchanger 2. The carbon dioxide PSA adsorption The carbon dioxide desorbed after adsorption by device 1 enters the carbon dioxide PSA adsorption device 2 through the compressor 1 to adsorb carbon dioxide, and the exhaust gas enters the carbon dioxide PSA adsorption device 1. The carbon dioxide desorbed after adsorption by the carbon dioxide PSA adsorption device 2 is purged and then enters the carbon dioxide liquefaction storage device for liquefied storage after passing through the compressor 2, the heat exchanger 2 and the heat exchanger 3; the purge gas used for purge desorption is obtained by the high-pressure carbon dioxide stored in the high-pressure storage tank entering the expansion power generation device through the heat exchanger 4 for expansion power generation, and then passing through the heat exchanger 4 and the heat exchanger 5.

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