Device and process for coupling pressure swing adsorption carbon capture and coal gas combustion waste heat utilization

Abstract

The present application relates to the field of adsorption technology, in particular to a device and process for coupling pressure swing adsorption carbon capture and coal gas combustion waste heat utilization, comprising a temperature swing adsorption pretreatment unit and a pressure swing adsorption unit, through the temperature swing adsorption pretreatment unit, impurity components in the blast furnace gas are adsorbed and removed, then through the pressure swing adsorption unit, high-purity CO2 product gas is obtained; the pressure swing adsorption unit adsorbs the remaining decarburization gas into high-temperature flue gas, and then enters the temperature swing adsorption pretreatment unit again for heat recovery, and at the same time, the heat is used to desorb the adsorbed impurity components in the blast furnace gas. The present application combines the blast furnace gas pretreatment and CO2 capture system, realizes the reuse of blast furnace gas and the efficient capture of CO2, improves the capture efficiency of CO2, reduces energy waste, and realizes the cyclic operation of the equipment.

Description

Technical Field

[0001] This invention relates to the field of adsorption technology, and in particular to an apparatus and process for coupling pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion. Background Technology

[0002] CO2 is a major greenhouse gas, and industrial coal gas accounts for a high proportion of CO2 emissions in my country each year, resulting in a huge demand for CO2 capture. For reducing CO2 emissions from industrial sources, adsorption capture is a promising carbon reduction technology. Depending on the process requirements, pressure swing adsorption (PSA) is suitable for the rapid and efficient capture of CO2 from coal gas.

[0003] However, while pressure swing adsorption (PSA) and temperature swing adsorption (TSA) have many advantages, they still have some limitations that restrict the large-scale application of these technologies. Currently, before PSA capture of CO2, impurities in the coal gas need to be removed to prevent them from affecting the concentration of subsequent CO2 products. TSA regeneration requires a large amount of heat energy, leading to high energy consumption during the thermal desorption process. Furthermore, the waste heat and CO in the flue gas are not effectively recovered and utilized, resulting in waste and environmental impact, increasing environmental pressure.

[0004] Based on the above, this invention designs a device and process for coupling pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion to solve the aforementioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a device and process for coupling pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a device for coupling pressure swing adsorption carbon capture and waste heat utilization of blast furnace gas, comprising a temperature swing adsorption pretreatment unit and a pressure swing adsorption unit. The temperature swing adsorption pretreatment unit adsorbs and removes impurity components in the blast furnace gas, and then the pressure swing adsorption unit obtains high-purity CO2 product gas. The remaining decarbonized gas adsorbed by the pressure swing adsorption unit is converted into high-temperature flue gas and then re-enters the temperature swing adsorption pretreatment unit for heat recovery. At the same time, the heat is used to desorb the adsorbed impurity components of the blast furnace gas.

[0007] Preferably, the temperature swing adsorption pretreatment unit includes at least two independently controlled adsorption towers, and several of the adsorption towers are respectively connected to the pressure swing adsorption unit. The blast furnace gas pretreated by the adsorption towers enters the pressure swing adsorption unit; the decarbonized gas remaining after adsorption is treated by the burner and then returned to the adsorption tower for further treatment.

[0008] Preferably, the adsorption tower includes a pretreatment module for pretreating blast furnace gas. A heat storage module is arranged around the pretreatment module. An annular flue gas channel is provided on the outer wall of the heat storage module. The flue gas channel is connected to a heat exchange component arranged in the pretreatment module. The high-temperature flue gas generated by the burner enters the flue gas channel, is cooled by the heat storage module, and then enters the heat exchange component.

[0009] Preferably, the pretreatment module includes a treatment cavity coaxially attached to the inner wall of the heat storage module. The treatment cavity is filled with a pretreatment adsorbent for pretreating blast furnace gas. The blast furnace gas passes through the pretreatment adsorbent to remove impurities from the blast furnace gas.

[0010] Preferably, the heat exchange assembly includes a flue gas coil bent within the pretreated adsorbent, the inlet of the flue gas coil being connected to the outlet of the flue gas channel, and the outlet of the flue gas coil being connected to a pressure swing adsorption unit for adsorbing CO2.

[0011] Preferably, the heat exchange assembly further includes a plurality of cooling water coils bent within the pretreated adsorbent to cool the pretreated adsorbent.

[0012] This invention also discloses a process for a device that couples pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion, comprising the following steps:

[0013] Blast furnace gas is pretreated by a temperature swing adsorption pretreatment unit, and then the pretreated blast furnace gas enters a pressure swing adsorption unit for pressure swing adsorption to obtain high-purity CO2 product gas.

[0014] The pressure swing adsorption unit adsorbs the remaining decarbonized coal gas, which then enters the burner for combustion to obtain high-temperature flue gas.

[0015] High-temperature flue gas enters the temperature-switching adsorption pretreatment unit for cooling treatment, while simultaneously recovering the heat from the high-temperature flue gas.

[0016] The cooled high-temperature flue gas is returned to the temperature-switching adsorption pretreatment unit for further cooling to obtain low-temperature flue gas, while simultaneously desorbing the impurities from the adsorbed blast furnace gas.

[0017] The low-temperature flue gas enters another pressure swing adsorption unit for pressure swing adsorption to obtain high-purity CO2 product gas;

[0018] After the impurity gas desorption is completed, the temperature-switched adsorption pretreatment unit is cooled down to facilitate further pretreatment of the blast furnace gas.

[0019] Preferably, the two steps of pretreatment of blast furnace gas and treatment of high-temperature flue gas in the variable temperature adsorption pretreatment unit are carried out in different adsorption towers.

[0020] Preferably, in the step of cooling the high-temperature flue gas into the variable temperature adsorption pretreatment unit, the high-temperature flue gas in the flue gas channel heats the heat storage module, and the heat storage module, after heat storage, heats the pretreated adsorbent in the adsorption chamber.

[0021] Preferably, in the variable temperature adsorption pretreatment unit, during the blast furnace gas pretreatment adsorption stage, the adsorption temperature of the pretreatment adsorbent is 30-80℃, and the desorption temperature of the pretreatment adsorbent is 00-200℃.

[0022] Compared with existing technologies, this invention has the following advantages and technical effects: This invention discloses a device and process for coupling pressure swing adsorption (PSA) carbon capture and waste heat utilization from coal gas combustion. Industrial coal gas undergoes temperature swing adsorption pretreatment followed by PSA CO2 capture. Unadsorbed coal gas is then subjected to CO2 capture again after combustion. By combining temperature swing adsorption pretreatment and PSA, CO2 is captured from the coal gas. Through this two-stage capture of CO2 from the industrial coal gas, high-purity product gas is obtained. The entire capture process achieves highly efficient CO2 capture. The temperature swing adsorption pretreatment unit pretreats the blast furnace gas, removing impurities, improving its purity, reducing pretreatment energy consumption, and increasing the CO2 capture rate. Simultaneously, the heat from the combustion of the decarbonized coal gas and CO2 are fully utilized, further enhancing the CO2 capture rate. Furthermore, the heat can be fully utilized for adsorbent regeneration, reducing heat loss and regeneration energy consumption.

[0023] This invention combines blast furnace gas pretreatment and CO2 capture systems, enabling the reuse of blast furnace gas and efficient CO2 capture, improving CO2 capture efficiency, reducing energy waste, and achieving cyclical operation of the equipment. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:

[0025] Figure 1 This is a flowchart of the device for coupling pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion according to the present invention.

[0026] Figure 2 This is a schematic diagram of the temperature-changing adsorption pretreatment unit structure of the present invention;

[0027] Figure 3 This is a top view of the adsorption tower structure of the present invention;

[0028] In the diagram: 1. Temperature adsorption pretreatment unit; 2. Pressure swing adsorption unit; 3. Burner; 4. CO2 product gas container; 5. Decarbonized gas container; 11. Adsorption tower; 12. Treatment chamber; 13. Heat storage module; 14. Flue gas passage; 15. Pretreatment adsorbent; 16. Flue gas coil; 17. Cooling water coil. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Reference Figures 1 to 3 As shown, this embodiment provides a device for coupling pressure swing adsorption (PSA) carbon capture and waste heat utilization from blast furnace gas combustion. It includes a temperature swing adsorption pretreatment unit 1 and a pressure swing adsorption unit 2. The temperature swing adsorption pretreatment unit 1 adsorbs and removes impurities from the blast furnace gas, and then the pressure swing adsorption unit 2 obtains high-purity CO2 product gas. The remaining decarbonized gas adsorbed by the pressure swing adsorption unit 2 is converted into high-temperature flue gas and then re-enters the temperature swing adsorption pretreatment unit 1 for heat recovery. At the same time, the heat is used to desorb the adsorbed impurities from the blast furnace gas.

[0032] This invention discloses an apparatus and process for coupling pressure swing adsorption (PSA) carbon capture and waste heat utilization from coal gas combustion. Industrial coal gas undergoes pretreatment with temperature swing adsorption (TSA) followed by PSA for CO2 capture. Unadsorbed coal gas is then combusted and subjected to another CO2 capture. By combining TSA pretreatment and PSA, CO2 is captured from the coal gas. Through this two-stage CO2 capture process, high-purity product gas is obtained. The entire capture process achieves highly efficient CO2 capture. The variable-temperature adsorption pretreatment unit 1 pretreats the blast furnace gas, removing impurities, improving its purity, reducing pretreatment energy consumption, and increasing CO2 capture rate. Simultaneously, the heat and CO2 from the combustion of the decarbonized gas are fully utilized, further enhancing CO2 capture rate. Furthermore, the heat is fully utilized for adsorbent regeneration, reducing heat loss and regeneration energy consumption. This invention combines blast furnace gas pretreatment and a CO2 capture system, achieving the reuse of blast furnace gas and efficient CO2 capture, improving CO2 capture efficiency, reducing energy waste, and enabling the equipment to operate in a cyclical manner.

[0033] In one embodiment of the present invention, the higher the CO2 concentration, the more favorable it is for CO2 to be captured by pressure swing adsorption. Therefore, the increased CO concentration after CO2 separation in the coal gas is fully utilized for combustion. The heat of combustion is used for the regeneration of the temperature swing adsorption tower 11. Then, the high CO2 concentration flue gas enters the pressure swing adsorption system for capture, and further obtains high-purity CO2 product gas. This is of great significance for the efficient capture of low-energy CO2 in industrial coal gas.

[0034] In one embodiment of the present invention, the high-purity CO2 product gas obtained after adsorption by the pressure swing adsorption unit 2 is stored in the CO2 product gas container 4.

[0035] In one embodiment of the present invention, after adsorption by the pressure swing adsorption unit 2, a portion of the decarbonized coal gas is fed into the burner 3 for combustion to process the CO; the other portion is stored in the decarbonized coal gas container 5 for other uses.

[0036] Further optimization of the scheme involves a temperature-switching adsorption pretreatment unit 1 comprising at least two independently controlled adsorption towers 11. Several adsorption towers 11 are connected to a pressure-switching adsorption unit 2. The blast furnace gas pretreated in the adsorption towers 11 enters the pressure-switching adsorption unit 2. The remaining decarbonized gas, after being processed by the burner 3, is returned to the adsorption towers 11 for further treatment. The presence of at least two independently operating adsorption towers 11 allows for separate pretreatment of the blast furnace gas and treatment of the high-temperature flue gas generated by the burner 3, achieving continuous operation of the pretreatment process and avoiding the alternating interruptions of adsorption and desorption in single-tower operation. Simultaneously, the design of returning the decarbonized gas after treatment by the burner 3 achieves a closed-loop waste heat recovery system, reducing heat loss and improving energy utilization efficiency.

[0037] Further optimizing the design, the adsorption tower 11 includes a pretreatment module for pretreating blast furnace gas. A heat storage module 13 surrounds the pretreatment module, and an annular flue gas channel 14 is provided on the outer wall of the heat storage module 13. The flue gas channel 14 is connected to a heat exchange component located in the treatment module. The high-temperature flue gas generated by the burner 3 enters the flue gas channel 14, is cooled by the heat storage module 13, and then enters the heat exchange component. The modular design of the adsorption tower 11 enables heat transfer from the outside to the inside, achieving high-efficiency recovery of high-temperature flue gas and reducing heat loss. The high-temperature flue gas first heats the heat storage module 13 through the flue gas channel 14, thus heating the pretreatment module, and then enters the heat exchange component to exchange heat with the pretreatment module. This extends the heat exchange time, improves heat recovery efficiency, and the recovered heat provides heat for the desorption of impurities adsorbed by the subsequent pretreatment component, eliminating the need for additional heat supply.

[0038] Further optimizing the design, the pretreatment module includes a treatment chamber 12 coaxially fitted to the inner wall of the heat storage module 13. The treatment chamber 12 is filled with a pretreatment adsorbent 15 for pretreating the blast furnace gas. The blast furnace gas passes through the pretreatment adsorbent 15, removing impurities. The coaxial fit between the treatment chamber 12 and the heat storage module 13 enhances heat conduction between the pretreatment adsorbent 15 and the heat storage module 13, ensuring efficient heat transfer to the pretreatment adsorbent 15 during desorption. Simultaneously, the heat exchange components are coiled within the pretreatment adsorbent 15, accelerating heat transfer and reducing heat loss. The filling structure of the pretreatment adsorbent 15 ensures sufficient contact between the blast furnace gas and the adsorbent, improving impurity removal efficiency.

[0039] The design is further optimized by including a flue gas coil 16, which is bent and installed within the pretreated adsorbent 15. The inlet of the flue gas coil 16 is connected to the outlet of the flue gas channel 14, and the outlet of the flue gas coil 16 is connected to the pressure swing adsorption unit 2 for CO2 adsorption. The bent design of the flue gas coil 16 increases the contact area with the pretreated adsorbent 15, allowing the cooled flue gas to fully exchange heat with the adsorbent. This not only continues to recover waste heat from the flue gas but also provides precise heat for the adsorbent to heat up and desorb. The connection between the flue gas coil 16 and the pressure swing adsorption unit 2 allows for secondary capture of CO2 in the cooled flue gas, improving the carbon capture rate.

[0040] In one embodiment of the present invention, the pretreatment adsorbent 15 includes any one or a combination of at least two of activated carbon, molecular sieves or alumina.

[0041] In one embodiment of the present invention, the pressure swing adsorbent in the pressure swing adsorption unit 2 includes any one or a combination of at least two of molecular sieves, silica gel, and ion exchange modified adsorbents.

[0042] To further optimize the design, the heat exchange assembly also includes several cooling water coils 17 bent within the pretreated adsorbent 15 to cool the pretreated adsorbent 15. The cooling water coils 17 are used to circulate cooling water after the desorption of impurity gases in the pretreated adsorbent 15 is completed, thereby cooling the pretreated adsorbent 15. After cooling, the adsorption tower 11 resumes the adsorption and removal of impurity components from the coal gas.

[0043] In one embodiment of the present invention, the cooling water coil 17 and the flue gas coil 16 adopt a tortuous circulation design, which increases their contact area with the pre-treated adsorbent 15 and accelerates the heat transfer efficiency.

[0044] This invention also discloses a process for a device that couples pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion, comprising the following steps:

[0045] Blast furnace gas is pretreated in temperature swing adsorption pretreatment unit 1. After pretreatment, the blast furnace gas enters pressure swing adsorption unit 2 for pressure swing adsorption to obtain high-purity CO2 product gas. After water, sulfur and other components are adsorbed and removed in temperature swing adsorption pretreatment unit 1, the blast furnace gas enters pressure swing adsorption unit 2 for CO2 pressure swing adsorption to obtain high-purity CO2 product gas. Other unadsorbed components are discharged from pressure swing adsorption unit 2 to obtain decarbonized gas.

[0046] The remaining decarbonized coal gas adsorbed by the pressure swing adsorption unit 2 enters the burner 3 for combustion to obtain high-temperature flue gas; the decarbonized coal gas enters the burner 3 for combustion to convert CO into CO2, and after combustion, high-temperature flue gas with high temperature and high concentration of CO2 is released. The high-temperature flue gas enters the flue gas channel 14 of the adsorption tower 11, which is in the regeneration stage of the pre-treated adsorbent 15.

[0047] High-temperature flue gas enters the temperature-switching adsorption pretreatment unit 1 for cooling treatment, and at the same time recovers the heat in the high-temperature flue gas; the high-temperature flue gas enters from one end of the adsorption tower 11, first enters the outer flue gas channel 14, and heats the inner heat storage block during the flow, while also completing a certain degree of cooling.

[0048] The cooled high-temperature flue gas is returned to the temperature-switched adsorption pretreatment unit 1 for further cooling to obtain low-temperature flue gas, while simultaneously desorbing the adsorbed impurities from the blast furnace gas. The cooled high-temperature flue gas then flows out from the other end of the flue gas channel 14 and re-enters the flue gas coil 16 in the middle of the adsorption tower 11, heating the adsorption chamber and desorbing the blast furnace gas impurities adsorbed on the pretreatment adsorbent 15. The resulting combustion flue gas is then further cooled.

[0049] The low-temperature flue gas enters another pressure swing adsorption unit 2 for pressure swing adsorption to obtain high-purity CO2 product gas; after the pretreated adsorbent 15 absorbs heat and cools down, the low-temperature flue gas enters another pressure swing adsorption system for CO2 capture to complete the remaining carbon recovery.

[0050] The temperature-controlled adsorption pretreatment unit 1, after the desorption of impurity gas is completed, is cooled down to facilitate the pretreatment of blast furnace gas again. After desorption, the adsorption tower 11 is cooled down by circulating water in the cooling water coil 17. After cooling, the adsorption tower 11 is used to adsorb and remove impurity components from the gas again.

[0051] To further optimize the scheme, the two steps of pretreatment of blast furnace gas and treatment of high-temperature flue gas in the variable-temperature adsorption pretreatment unit 1 are carried out in different adsorption towers 11. Different adsorption towers 11 are used to treat blast furnace gas pretreatment and high-temperature flue gas separately, realizing parallel operation of adsorption and desorption, eliminating the time loss of alternating operation of a single tower, and improving the continuous processing capacity of the system.

[0052] In a further optimized scheme, during the cooling process of the high-temperature flue gas entering the variable-temperature adsorption pretreatment unit 1, the high-temperature flue gas in the flue gas channel 14 heats the heat storage module 13, and the heat storage module 13, after heat storage, raises the temperature of the pretreated adsorbent 15 in the adsorption chamber. The heat storage-heat release mechanism of the heat storage module 13 realizes the buffering and reuse of heat, avoids the thermal shock caused by direct heat exchange of high-temperature flue gas, and makes the adsorbent heating process more stable, improving desorption efficiency and adsorbent life.

[0053] Further optimization of the scheme: In the variable-temperature adsorption pretreatment unit 1, during the pretreatment adsorption stage of blast furnace gas, the adsorption temperature of pretreatment adsorbent 15 is 30-80℃, and the desorption temperature of pretreatment adsorbent 15 is 100-200℃. By clarifying the adsorption and desorption temperature parameters of pretreatment adsorbent 15, precise temperature control ensures efficient adsorption of impurities while guaranteeing complete desorption, preventing adsorbent performance degradation, and maintaining long-term stable system operation.

[0054] Specific Example 1

[0055] The following explanation uses blast furnace gas from iron and steel as the raw material for CO2 capture. Its composition is shown in Table 1. The pretreatment adsorbent 15 is alumina, and the adsorbent used in pressure swing adsorption is molecular sieve.

[0056] Table 1

[0057] <![CDATA[CO2(%)]]> CO (%) <![CDATA[H2O(%)]]> <![CDATA[H2(%)]]> <![CDATA[N2(%)]]> <![CDATA[CH4(%)]]> <![CDATA[O2(%)]]> <![CDATA[H2S / COS(ppm)]]> Blast furnace gas 20 5 6.00 3 45.5 0.2 0.3 200

[0058] Specifically, each adsorption tower 11 is filled with alumina at a rate of 6000 kg, and blast furnace gas enters the pretreatment module at a rate of 1000 Nm3 / h. The adsorption temperature is 50℃ and the desorption temperature is 150℃.

[0059] The pretreated blast furnace gas and the treated low-temperature flue gas after combustion are respectively introduced into different pressure swing adsorption units 2. Each adsorption unit is filled with molecular sieves with a loading amount of 2500 kg. The adsorption pressure is 500 kPa, the adsorption temperature is 50℃, the adsorption time is 10 min, the vacuum desorption pressure is 10 kPa, and the total vacuum desorption time is 10 min, finally obtaining the product gas.

[0060] The composition of the product gas obtained in this embodiment is shown in Table 2.

[0061] Table 2

[0062] <![CDATA[CO2(%)]]> CO (%) <![CDATA[H2O(%)]]> <![CDATA[H2(%)]]> <![CDATA[N2(%)]]> <![CDATA[CH4(%)]]> <![CDATA[O2(%)]]> <![CDATA[H2S / COS(ppm)]]> Product Air 1 95.1 1.5 0.02 0 3.2 0.08 0.1 0

[0063] The technical solution of this embodiment yielded a CO2 product gas purity of 95.1%.

[0064] Comparison Example 1

[0065] Compared with Example 1, the difference is that the pretreatment stage of blast furnace gas uses electrolytic heat to regenerate the adsorbent in the temperature-switching adsorption tower 11, and does not perform re-adsorption and capture of CO2 in the combustion gas.

[0066] Specifically, each adsorption tower is filled with 6000 kg of alumina in 11 zones, and the blast furnace gas feed gas flow rate is 1000 Nm3 / h. It enters the pretreatment system, with an adsorption temperature of 50℃ and a desorption temperature of 150℃.

[0067] After pretreatment, the coal gas enters the pressure swing adsorption unit 2. Each adsorption zone is filled with molecular sieves with a loading amount of 2500 kg. The adsorption pressure is 500 kPa, the adsorption temperature is 50℃, the adsorption time is 10 min, the vacuum desorption pressure is 10 kPa, and the total vacuum desorption time is 10 min, finally yielding the product gas.

[0068] The gas composition of the product obtained in this comparative example is shown in Table 3.

[0069] Table 3

[0070] <![CDATA[CO2(%)]]> CO (%) <![CDATA[H2O(%)]]> <![CDATA[H2(%)]]> <![CDATA[N2(%)]]> <![CDATA[CH4(%)]]> <![CDATA[O2(%)]]> <![CDATA[H2S / COS(ppm)]]> <![CDATA[Product gas 2]]> 84.1 2.6 0.02 0 13.1 0.1 0.08 0

[0071] The comparative example yielded a CO2 product gas purity of 84.1%, which is 11% lower than that of Specific Example 1.

[0072] In the description of this invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this invention, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0073] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A device for coupling pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion, characterized in that: It includes a temperature swing adsorption pretreatment unit (1) and a pressure swing adsorption unit (2). The temperature swing adsorption pretreatment unit (1) adsorbs and removes impurities in the blast furnace gas, and then the pressure swing adsorption unit (2) obtains high-purity CO2 product gas. The pressure swing adsorption unit (2) adsorbs the remaining decarbonized gas and converts it into high-temperature flue gas, which then re-enters the temperature swing adsorption pretreatment unit (1) for heat recovery. At the same time, the heat is used to desorb the adsorbed impurities in the blast furnace gas. The temperature swing adsorption pretreatment unit (1) includes no less than two independently controlled adsorption towers (11), and several of the adsorption towers (11) are connected to the pressure swing adsorption unit (2). The blast furnace gas pretreated by the adsorption towers (11) enters the pressure swing adsorption unit (2). The decarbonized gas remaining after adsorption is treated by the burner (3) and then returned to the adsorption towers (11) for further treatment. The adsorption tower (11) includes a pretreatment module for pretreating blast furnace gas. A heat storage module (13) is arranged around the pretreatment module. An annular flue gas channel (14) is provided on the outer wall of the heat storage module (13). The flue gas channel (14) is connected to the heat exchange component in the treatment module. The high-temperature flue gas generated by the burner (3) enters the flue gas channel (14), and after being cooled by the heat storage module (13), it enters the heat exchange component. The pretreatment module includes a treatment chamber (12) coaxially attached to the inner wall of the heat storage module (13). The treatment chamber (12) is filled with a pretreatment adsorbent (15) for pretreatment of blast furnace gas. The blast furnace gas passes through the pretreatment adsorbent (15) to remove impurities from the blast furnace gas. The heat exchange assembly includes a flue gas coil (16) bent and disposed within the pretreated adsorbent (15). The inlet of the flue gas coil (16) is connected to the outlet of the flue gas channel (14), and the outlet of the flue gas coil (16) is connected to a pressure swing adsorption unit (2) for adsorbing CO2. The heat exchange assembly also includes several cooling water coils (17) bent in the pretreated adsorbent (15) to cool the pretreated adsorbent (15).

2. A process for coupled pressure swing adsorption (PSA) carbon capture and waste heat utilization from coal gas combustion, based on the apparatus for coupled PSA carbon capture and waste heat utilization from coal gas combustion as described in claim 1, characterized in that, Includes the following steps: Blast furnace gas is pretreated by temperature swing adsorption pretreatment unit (1), and the pretreated blast furnace gas enters pressure swing adsorption unit (2) for pressure swing adsorption to obtain high-purity CO2 product gas. The pressure swing adsorption unit (2) adsorbs the remaining decarbonized coal gas and enters the burner (3) for combustion to obtain high-temperature flue gas; High-temperature flue gas enters the temperature-switching adsorption pretreatment unit (1) for cooling treatment, and at the same time recovers the heat in the high-temperature flue gas; The cooled high-temperature flue gas is returned to the temperature-switching adsorption pretreatment unit (1) for further cooling to obtain low-temperature flue gas, while desorbing the impurities from the adsorbed blast furnace gas. The low-temperature flue gas enters another pressure swing adsorption unit (2) for pressure swing adsorption to obtain high-purity CO2 product gas; The temperature-switching adsorption pretreatment unit (1) after the desorption of impurity gases is completed is cooled down to facilitate the pretreatment of blast furnace gas again.

3. The process for coupled pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion according to claim 2, characterized in that: In the variable temperature adsorption pretreatment unit (1), the two steps of pretreatment of blast furnace gas and treatment of high temperature flue gas are carried out in different adsorption towers (11).

4. The process for coupled pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion according to claim 2, characterized in that: In the process of cooling the flue gas entering the temperature-controlled adsorption pretreatment unit (1), the high-temperature flue gas in the flue gas channel (14) heats the heat storage module (13), and the heat storage module (13) heats the pretreated adsorbent (15) in the adsorption chamber after heat storage.

5. The process for coupled pressure swing adsorption carbon capture and waste heat utilization from coal gas combustion according to claim 2, characterized in that: In the variable temperature adsorption pretreatment unit (1), during the pretreatment adsorption stage of blast furnace gas, the adsorption temperature of the pretreatment adsorbent (15) is 30-80℃, and the desorption temperature of the pretreatment adsorbent (15) is 100-200℃.

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