Adsorption regeneration process and system for low-temperature flue gas cold energy recovery

Abstract

An adsorption regeneration process and system for low-temperature flue gas cold energy recovery. The adsorption regeneration process comprises: an adsorption step, in which a low-temperature flue gas with a temperature below room temperature enters an adsorption tower (100) so as to be adsorbed and purified by an adsorbent in the adsorption tower (100) into purified flue gas; and a regeneration step, in which the adsorption-saturated adsorbent is heated into a high-temperature adsorbent in a regeneration tower (200) so as to regenerate the adsorbent. By means of heat exchange between the purified flue gas and the high-temperature adsorbent, the high-temperature adsorbent is cooled to a low-temperature adsorbent having a reduced temperature, and the low-temperature adsorbent is conveyed into the adsorption tower (100), such that the low-temperature flue gas entering the adsorption tower (100) is adsorbed and purified into purified flue gas, and the adsorption-saturated adsorbent in the adsorption tower (100) is conveyed into the regeneration tower (200) for heating and regeneration.

Description

Adsorption regeneration process and system for recovering cold energy from low-temperature flue gas

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number 2023115124877 and application date of November 14, 2023, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] The present disclosure relates to the field of flue gas adsorption technology, and in particular to an adsorption regeneration process and system for recovering cold energy from low-temperature flue gas. Background Art

[0004] In order to protect the environment and human health, flue gas adsorption towers are often used in related technologies to remove pollutants from flue gas. Traditional flue gas adsorption is usually high-temperature adsorption, that is, the flue gas discharged from the boiler is cooled to approximately 200°C through a cooling tower, and then enters the flue gas adsorption tower for high-temperature adsorption purification. However, high-temperature flue gas adsorption has the problems of large adsorbent consumption, poor adsorption effect, high nitrogen oxide content in the clean flue gas after adsorption, and inability to achieve near-zero emissions.

[0005] To overcome the problem of high-temperature adsorption, related technologies have proposed low-temperature flue gas adsorption technology, which involves cooling the flue gas to a low-temperature level, such as below room temperature, and then removing the pollutant components in the flue gas through adsorption. In low-temperature adsorption, the adsorption capacity of the adsorbent increases exponentially in a low-temperature environment, greatly improving the adsorption purification rate compared to conventional high-temperature flue gas adsorption, and achieving near-zero flue gas emissions. However, during the low-temperature flue gas adsorption process, the adsorption effect of the flue gas is highly sensitive to the adsorption temperature. Therefore, in actual engineering applications, providing an ideal low-temperature adsorption environment is of great significance to ensuring the adsorption effect of the flue gas.

[0006] Summary of the Invention

[0007] The present disclosure proposes an adsorption regeneration process for recovering cold energy from low-temperature flue gas.

[0008] The adsorption regeneration process for recovering the cooling capacity of low-temperature flue gas in the embodiment of the present disclosure includes:

[0009] Adsorption step: low-temperature flue gas with a temperature below room temperature enters the adsorption tower to be adsorbed and purified into clean flue gas by the adsorbent in the adsorption tower; and

[0010] Regeneration step: heating the adsorbent saturated with adsorption to a high-temperature adsorbent in a regeneration tower to regenerate the adsorbent;

[0011] The clean flue gas is heat exchanged with the high-temperature adsorbent, and the high-temperature adsorbent is cooled to a low-temperature adsorbent with a reduced temperature, which is then transported to the adsorbent bed in the adsorption tower. This allows the low-temperature flue gas entering the adsorption tower to be adsorbed and purified into clean flue gas, and the adsorbent that has been saturated with adsorption in the adsorption tower is transported to the regeneration tower for heating and regeneration.

[0012] In some embodiments, the clean flue gas and the high-temperature adsorbent undergo heat exchange in the adsorption tower, and the clean flue gas after heat exchange is discharged from the adsorption tower through a flue gas outlet.

[0013] In some embodiments, the low-temperature flue gas flows from bottom to top and is discharged from the adsorption tower after completing adsorption and heat exchange in sequence, and the high-temperature adsorbent flows from top to bottom and is discharged from the adsorption tower after completing heat exchange and adsorption in sequence.

[0014] In some embodiments, in the adsorption step, the low-temperature flue gas and the adsorbent flow in a countercurrent or cross-current manner in the adsorption tower.

[0015] In some embodiments, the temperature of the high-temperature adsorbent is 50 degrees Celsius to 300 degrees Celsius, and the temperature of the low-temperature adsorbent is 0 degrees Celsius to 30 degrees Celsius.

[0016] In some embodiments, regenerating the adsorbent in the regeneration column comprises:

[0017] a preheating step of preheating the adsorbent entering the regeneration tower to 80 degrees Celsius to 110 degrees Celsius;

[0018] The heating step heats the preheated adsorbent to 250 degrees Celsius to 350 degrees Celsius to desorb and regenerate the adsorbent.

[0019] In some embodiments, regenerating the adsorbent in the regeneration tower further includes a cooling step, using the clean flue gas to cool the regenerated adsorbent to a temperature of 80 degrees Celsius to 250 degrees Celsius.

[0020] In some embodiments, a material transport device for transporting adsorbent is provided between the feed inlet of the adsorption tower and the discharge outlet of the regeneration tower, the material transport device including a cooling air inlet and a cooling air outlet, and the adsorption regeneration process further includes:

[0021] The clean flue gas after heat exchange with the high-temperature adsorbent enters the material transport device through the cooling gas inlet to contact the adsorbent in the material transport device to cool the adsorbent, and then is discharged from the cooling gas outlet.

[0022] The present disclosure also provides an adsorption regeneration system.

[0023] The adsorption regeneration system provided by the embodiment of the present disclosure includes an adsorption tower and a regeneration tower, wherein the adsorption tower has a first feed port, a first discharge port, a flue gas inlet, and a flue gas outlet, and the regeneration tower has a second feed port and a second discharge port, the first discharge port of the adsorption tower is connected to the second feed port of the regeneration tower, and the first feed port of the adsorption tower is connected to the second discharge port of the regeneration tower.

[0024] wherein low-temperature flue gas having a temperature below room temperature enters the adsorption tower through the flue gas inlet, is adsorbed and purified by the adsorbent in the adsorption tower and discharged as clean flue gas from the flue gas outlet, and the adsorbent saturated with adsorption is heated in the regeneration tower to become a high-temperature adsorbent to regenerate the adsorbent;

[0025] The clean flue gas is heat-exchanged with the high-temperature adsorbent to cool the high-temperature adsorbent into a low-temperature adsorbent with a reduced temperature, and the adsorbent is transported into the adsorption tower through the first feed port. The adsorbent that has been saturated with adsorption in the adsorption tower is discharged from the first discharge port and transported to the regeneration tower through the second feed port. The adsorbent that has been regenerated in the regeneration tower is discharged from the second discharge port.

[0026] In some embodiments, the clean flue gas and the high-temperature adsorbent are heat exchanged in the adsorption tower.

[0027] The adsorption regeneration system and process provided by the disclosed embodiments utilize the cooling energy of low-temperature clean flue gas to cool the adsorbent prior to adsorption, thereby reducing the adsorbent temperature during adsorption and improving adsorption efficiency. Because the adsorbent is cooled by heat exchange with the low-temperature clean flue gas before adsorption, the cooling load of the regeneration tower cooling section is reduced, thereby reducing the structural complexity, energy consumption, and regeneration costs of the regeneration tower cooling section. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] FIG1 is a schematic structural diagram of an adsorption regeneration system provided in an embodiment of the present disclosure.

[0029] FIG2 is a schematic diagram of the internal structure of the adsorption tower provided in an embodiment of the present disclosure.

[0030] Figure markings: adsorption tower 100, first feed port 111, first discharge port 112, flue gas inlet 113, flue gas outlet 114, adsorption module 120, adsorption bed 121, heat exchange module 130, cold side flow channel 131, hot side flow channel 132, baffle 133, heat exchange tube 134, feed chamber 140, blanking chamber 150, flue gas distributor 160, regeneration tower 200, second feed port 211, second discharge port 212, preheating section 220, heating section 230, cooling section 240, material transport device 300, cooling gas inlet 311, cooling gas outlet 312, transmission equipment 310, sealed box 320. DETAILED DESCRIPTION

[0031] The embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present disclosure, but should not be understood as limiting the present disclosure.

[0032] The present disclosure is based on the inventors' findings and understanding of the following facts and problems:

[0033] The low-temperature flue gas adsorption system in the related art uses an adsorption tower to purify the flue gas through adsorption, and a regeneration tower to heat and regenerate the adsorbent. The adsorbent after heating and regeneration is sent back to the adsorption tower for continued adsorption. However, the temperature of the adsorbent after heating and regeneration is relatively high. The high-temperature adsorbent is sent into the adsorption tower to contact the low-temperature flue gas, which greatly affects the low-temperature adsorption efficiency and adsorption effect in the adsorption tower. In order to reduce the temperature of the adsorbent after regeneration, a regeneration tower with a cooling section is proposed in the related art, that is, the heated and regenerated adsorbent is sent into the cooling section for cooling and then output. However, the temperature of the adsorbent after cooling in the cooling section is still relatively high (about 80°C to 100°C) compared to the temperature of the low-temperature flue gas (below room temperature), and its impact on low-temperature adsorption cannot be ignored.

[0034] In this regard, embodiments of the present disclosure provide an adsorption regeneration system and an adsorption regeneration process.

[0035] The following describes an adsorption regeneration process and an adsorption regeneration system for recovering cold energy from low-temperature flue gas provided by an embodiment of the present disclosure with reference to FIG1-FIG2 . The adsorption regeneration system operates based on the adsorption regeneration process.

[0036] As shown in Figure 1, the adsorption regeneration system includes an adsorption tower 100 and a regeneration tower 200. The adsorption tower 100 has a first feed port 111, a first discharge port 112, a flue gas inlet 113 and a flue gas outlet 114. The regeneration tower 200 has a second feed port 211 and a second discharge port 212. The first discharge port 112 of the adsorption tower 100 is connected to the second feed port 211 of the regeneration tower 200 (not shown in the figure), and the first feed port 111 of the adsorption tower 100 is connected to the second discharge port 212 of the regeneration tower 200 (not shown in the figure).

[0037] In the embodiment of the present disclosure, low-temperature flue gas with a temperature below room temperature enters the adsorption tower through the flue gas inlet 113, is adsorbed and purified by the adsorbent in the adsorption tower and discharged from the flue gas outlet 114 as clean flue gas, and the adsorbent saturated with adsorption is heated in the regeneration tower 200 to be a high-temperature adsorbent to regenerate the adsorbent.

[0038] In the embodiment of the present disclosure, the clean flue gas is heat exchanged with the high-temperature adsorbent to cool the high-temperature adsorbent into a low-temperature adsorbent with a reduced temperature and transported to the adsorption tower 100 through the first feed port 111. The adsorbent that has been saturated with adsorption in the adsorption tower 100 is discharged from the first discharge port 112 and transported to the regeneration tower 200 through the second feed port 211. The adsorbent that has been regenerated in the regeneration tower 100 is discharged from the second discharge port 212.

[0039] The adsorbent discharged from the regeneration tower 200 is generally at a higher temperature, and is therefore referred to as "high-temperature adsorbent." Depending on the cooling capacity of the cooling section in the regeneration tower 200, the temperature of the high-temperature adsorbent can range from 50°C to 250°C, for example. It should be noted that the "low temperature" in "low-temperature adsorbent" herein is relative to the "high temperature" in "high-temperature adsorbent," meaning that the temperature of the low-temperature adsorbent is lower than that of the high-temperature adsorbent.

[0040] The adsorption regeneration process for recovering cold energy from low-temperature flue gas provided in the embodiments of the present disclosure includes:

[0041] Adsorption step: low-temperature flue gas with a temperature below room temperature enters the adsorption tower 100 and is adsorbed and purified by the adsorbent in the adsorption tower 100 to become clean flue gas; and

[0042] Regeneration step: heating the adsorbent saturated with adsorption to a high-temperature adsorbent in the regeneration tower 200 to regenerate the adsorbent;

[0043] The clean flue gas is heat exchanged with the high-temperature adsorbent, and the high-temperature adsorbent is cooled to a low-temperature adsorbent with a reduced temperature and transported to the adsorption bed in the adsorption tower 100, so that the low-temperature flue gas entering the adsorption tower 100 is adsorbed and purified into clean flue gas, and the adsorbent that has been saturated with adsorption in the adsorption tower 100 is transported to the regeneration tower 200 for heating and regeneration.

[0044] The adsorption regeneration system and process provided by the disclosed embodiments utilize the cooling energy of low-temperature clean flue gas to cool the high-temperature adsorbent entering the adsorption tower, thereby reducing the adsorbent's temperature upon contact with the low-temperature flue gas. This reduced contact temperature improves adsorption efficiency. Since the adsorbent is cooled by heat exchange with the low-temperature clean flue gas after entering the adsorption tower, the cooling load of the regeneration tower is reduced, thereby reducing the structural complexity of the regeneration tower and the regeneration cost.

[0045] In some embodiments, the clean flue gas and the high-temperature adsorbent undergo heat exchange in the adsorption tower, and the clean flue gas after heat exchange is discharged from the adsorption tower from the flue gas outlet. That is, the adsorbent undergoes heat exchange with the clean flue gas in the adsorption tower, and the low-temperature adsorbent after heat exchange then completes the purification of the flue gas in the adsorption tower.

[0046] Furthermore, the low-temperature flue gas flows from bottom to top, completes adsorption and heat exchange in sequence, and then exits the adsorption tower 100, while the high-temperature adsorbent flows from top to bottom, completes heat exchange and adsorption in sequence, and then exits the adsorption tower 100. In other words, the adsorption step and the heat exchange step are performed simultaneously in the adsorption tower 100.

[0047] As an example, as shown in FIG2 , an adsorption module 120 and a heat exchange module 130 are provided in the tower body of the adsorption tower 100. The adsorption module 120 is located below the heat exchange module 130, the flue gas inlet 113 is located below the flue gas outlet 114, and the first discharge port 112 is located below the first feed port 111. In accordance with the principle that flue gas flows upward and adsorbent flows downward under the action of gravity, the low-temperature flue gas entering from the flue gas inlet 113 is adsorbed by the low-temperature adsorbent after heat exchange in the adsorption module 120 to become low-temperature clean flue gas, and then flows upward into the heat exchange module 130 to exchange heat with the entering high-temperature adsorbent, and the cooled adsorbent becomes a low-temperature adsorbent. Similarly, the high-temperature adsorbent entering from the first feed port 111 flows downward into the adsorption module 120 for adsorption after heat exchange with the low-temperature clean flue gas in the heat exchange module 130, and is finally discharged from the first discharge port 112 at the bottom.

[0048] In some embodiments, during the adsorption step, the low-temperature flue gas and the low-temperature adsorbent flow in countercurrent directions, with the low-temperature flue gas flowing upward and the low-temperature adsorbent flowing downward. For example, as shown in FIG2 , in an adsorption tower 100 , the adsorption bed 121 formed by stacking adsorbents is a countercurrent adsorption bed, with the low-temperature flue gas flowing in the gaps between the adsorbents.

[0049] Alternatively, in some alternative embodiments, the low-temperature flue gas and the low-temperature adsorbent flow in a cross-flow pattern during the adsorption step. The adsorbent stacks in the adsorption tower 100 form a cross-flow adsorption bed, and the low-temperature flue gas and the adsorbent flow in a cross-flow pattern. Cross-flow of the low-temperature flue gas and the adsorbent means that the low-temperature flue gas passes vertically through the cross-flow adsorption bed, contacting and adsorbing the bed as it passes through.

[0050] In some embodiments, the temperature of the high temperature adsorbent is between 50 degrees Celsius and 300 degrees Celsius.

[0051] In some embodiments, the temperature of the low-temperature adsorbent after adsorption and heat exchange with the low-temperature clean flue gas is 0 degrees Celsius to 30 degrees Celsius. The contact of the low-temperature adsorbent with the low-temperature flue gas is conducive to improving the adsorption efficiency.

[0052] In some embodiments, the temperature of the high-temperature adsorbent input into the adsorption tower 100 from the first feed port 111 is less than 100 degrees Celsius to ensure that the temperature of the low-temperature adsorbent after contacting and exchanging heat with the low-temperature clean flue gas in the heat exchange module 130 is low enough to further improve the adsorption efficiency.

[0053] In some embodiments, the temperature of the low-temperature flue gas entering the adsorption tower 100 from the flue gas inlet 113 is below zero.

[0054] In some embodiments, the temperature of the low-temperature flue gas entering the adsorption tower 100 from the flue gas inlet 113 is below zero, for example, -80°C to -5°C.

[0055] In some embodiments, the low-temperature flue gas has a temperature of -20°C to -5°C. The inventors have discovered through research that the lower the flue gas temperature, the more beneficial it is for adsorption purification. However, too low a flue gas temperature complicates the structure of the flue gas cooling equipment and increases energy consumption. For example, insulation layers are required for the cooling equipment, adsorption tower, and pipelines, requiring high sealing performance, which increases costs. Furthermore, excessively low temperatures can easily lead to condensation in the adsorption tower, causing the adsorbent to stick and clog, affecting adsorption. Therefore, cooling the flue gas to a temperature of -20°C to -5°C is advantageous.

[0056] In some embodiments, the regeneration performed in the regeneration tower 200 includes:

[0057] Preheating step, preheating the adsorbent entering the regeneration tower 200 to 80 degrees Celsius to 110 degrees Celsius;

[0058] The heating step heats the preheated adsorbent to 250 degrees Celsius to 350 degrees Celsius to desorb and regenerate the adsorbent.

[0059] Furthermore, regenerating the adsorbent in the regeneration tower 200 also includes a cooling step, using the clean flue gas to cool the regenerated adsorbent to 80 degrees Celsius to 250 degrees Celsius, and then inputting the cooled adsorbent into the adsorption tower 100 for adsorption.

[0060] In some embodiments, in the cooling step, the regenerated adsorbent is cooled to below 100 degrees Celsius using clean flue gas, and the temperature of the high-temperature adsorbent input into the adsorption tower 100 from the first feed port 111 is less than 100 degrees Celsius to ensure that the temperature of the low-temperature adsorbent after contact and heat exchange with the low-temperature clean flue gas in the heat exchange module 130 is low enough to further improve the adsorption efficiency.

[0061] Incorporating a cooling step into the regeneration process to pre-cool the adsorbent ensures a sufficiently low temperature after heat exchange, further improving adsorption efficiency. Because the adsorbent is cooled by heat exchange with the low-temperature clean flue gas after entering the adsorption tower, the cooling load during the cooling step is low, helping to reduce the structural complexity of the regeneration tower and regeneration costs.

[0062] Furthermore, in the cooling step, the regenerated adsorbent can be cooled using the low-temperature clean flue gas discharged from the flue gas outlet 114 of the adsorption tower 100. That is, the cooling energy required to cool the adsorbent in the cooling step can come from the low-temperature clean flue gas discharged from the flue gas outlet 114 of the adsorption tower 100, thereby further recycling the cooling energy in the flue gas and avoiding cooling energy loss.

[0063] Of course, in some embodiments, the cooling capacity of the heat exchange module 130 in the adsorption tower 100 can meet the cooling requirements, and after the adsorbent is heated and regenerated, the high-temperature adsorbent can be directly input into the adsorption tower 100. In the above embodiment, the heat exchange function of the heat exchange module 130 in the adsorption tower 100 directly replaces the cooling step of the regeneration tower 200, reducing the structural complexity of the regeneration tower 200 and the regeneration cost.

[0064] The adsorption regeneration system provided by a specific embodiment of the present disclosure and the adsorption regeneration process based on the adsorption regeneration system are described below with reference to FIG1 and FIG2 .

[0065] As shown in Figures 1 and 2, the adsorption regeneration system includes an adsorption tower 100 and a regeneration tower 200. The adsorption tower 100 is provided with a first feed inlet 111 at the top and a first discharge port 112 at the bottom. A flue gas inlet 113 and a flue gas outlet 114 are provided on the sidewalls, with the flue gas inlet 113 located below the flue gas outlet 114. An adsorption module 120 and a heat exchange module 130 are provided within the tower of the adsorption tower 100. The adsorption module 120 is located below the heat exchange module 130, the flue gas inlet 113 is located below the adsorption module 120, and the flue gas outlet 114 is located above the heat exchange module 130.

[0066] The adsorption tower 100 further defines a feed chamber 140 and a discharge chamber 150. A first feed port 111 communicates with the feed chamber 140. The feed chamber 140 is located above the heat exchange module 130 and is used to distribute adsorbent into the heat exchange module 130. The discharge chamber 150 is located below the adsorption module 120 and is used to receive adsorbent that falls from the adsorption module 120. The first discharge port 112 is located at the bottom of the discharge chamber 150 and communicates with it. Adsorbent enters the feed chamber 140 through the first feed port 111 and is distributed to the heat exchange module 130 to complete heat exchange with the flue gas. Low-temperature adsorbent enters the adsorption module 120 for adsorption. The adsorbed adsorbent then falls into the discharge chamber 150 and is ultimately discharged through the first discharge port 112.

[0067] In order to allow the adsorbent in the blanking cavity 226 to be discharged more smoothly from the first discharge port 112 , as shown in FIG. 2 , the blanking cavity 150 is made into an inverted cone shape, and the first discharge port 112 is located at the bottom of the blanking cavity 150 .

[0068] As shown in Figure 2, the adsorption tower 100 also includes a flue gas distributor 160, which is connected to the flue gas inlet 113. In the disclosed embodiment, the adsorption tower 100 is provided with two opposing flue gas inlets 113, and the flue gas distributor 160 is connected to both flue gas inlets 113. The flue gas distributor 160 is located between the adsorption module 120 and the blanking chamber 150, and is used to ensure that the low-temperature flue gas enters the adsorption module 120 evenly.

[0069] As shown in Figure 2, in the adsorption module 120, the adsorbent is stacked and filled to form a countercurrent adsorption bed 121, with the low-temperature flue gas and the adsorbent flowing in opposite directions. The low-temperature flue gas entering the adsorption tower 100 from the flue gas inlet 113 is distributed by the flue gas distributor 160 and flows upward. After heat exchange and cooling in the heat exchange module 130, it flows downward into the low-temperature adsorption tower.

[0070] In the embodiment of the present disclosure, the heat exchange module 130 is a folded plate heat exchanger. The folded plate heat exchanger has a cold side flow channel 131 and a hot side flow channel 132. The low-temperature flue gas (clean flue gas) flows upward in the cold side flow channel 131, and the adsorbent flows downward in the hot side flow channel 132. As shown in Figure 1, the folded plate heat exchanger includes a plurality of baffles 133 and a plurality of heat exchange tubes 134. The heat exchange tubes 134 are arranged vertically, and the plurality of heat exchange tubes 134 are arranged at intervals on the horizontal plane. The hot side flow channel 132 is defined in the heat exchange tubes 134. The top inlet of the heat exchange tube 134 is connected to the feed chamber 140. The adsorbent in the feed chamber 140 is distributed to the plurality of vertically extending heat exchange tubes 134 and flows downward. The bottom outlet of the heat exchange tube 134 is connected to the adsorption bed 121. The baffles 133 are arranged horizontally, and several baffles 133 are arranged at intervals in the vertical direction. A serpentine cold side flow channel 131 is defined between the baffles 133. The low-temperature clean flue gas discharged from the adsorption module 120 flows upward along the serpentine cold side flow channel 131 and exchanges heat with the adsorbent in the heat exchange tube 134, thereby reducing the temperature of the adsorbent.

[0071] In addition, after passing through the adsorption bed 121, the low-temperature flue gas will carry out some adsorbent powder (for example, if the adsorbent is activated carbon, the low-temperature flue gas will carry out carbon powder). When the low-temperature flue gas flows in the serpentine cold side flow channel 131, it will be intercepted by the baffle 133, which is beneficial to reduce the amount of dust in the clean flue gas.

[0072] In other embodiments, in order to improve the heat exchange efficiency and increase the heat exchange area, the heat exchange tube 134 is a serpentine tube, which defines a serpentine hot-side flow channel 132 therein.

[0073] As shown in Figure 1, the regeneration tower 200 is provided with a second feed inlet 211 at the top and a second discharge outlet 212 at the bottom. The regeneration tower 200 comprises, from top to bottom, a preheating section 220, a heating section 230, and a cooling section 240. In the preheating section 220, the adsorbent is preheated. In the heating section 230, the preheated adsorbent is heated to release pollutants from the adsorbent, forming regeneration gas. The regeneration gas is then output from the regeneration tower 200 for post-processing. The desorbed adsorbent then flows downward into the cooling section 240, where it is initially cooled. The cooled adsorbent then flows out of the second discharge outlet 212 at the bottom.

[0074] The cooling section 240 is provided with a cooling medium inlet (not shown) and a cooling medium outlet (not shown). In some embodiments of the present disclosure, the flue gas outlet 114 of the adsorption tower 100 is connected to the cooling medium inlet of the cooling section 240 (not shown). Low-temperature clean flue gas is input into the cooling section 240 to cool the regenerated adsorbent, and then discharged from the cooling medium outlet and discharged into the atmosphere through a chimney.

[0075] Of course, in other embodiments, cooling water or coolant can be input into the cooling section 240 for cooling. In some embodiments of the present disclosure, low-temperature clean flue gas is used for cooling to recycle cold energy.

[0076] The adsorption regeneration system provided by the disclosed embodiments utilizes the cold energy of low-temperature clean flue gas to cool the adsorbent entering the adsorption tower, reducing its contact temperature with the flue gas and improving the tower's adsorption efficiency. This system recovers and efficiently utilizes the cold energy of the low-temperature flue gas, preventing cold energy loss and improving energy efficiency.

[0077] The adsorption regeneration process for recovering the cooling capacity of low-temperature flue gas in the embodiment of the present disclosure includes:

[0078] The regenerated high-temperature adsorbent is fed into the adsorption tower 100 from the first feed port 111, and the low-temperature flue gas at -20 degrees Celsius enters the adsorption tower 100 from the flue gas inlet 113;

[0079] In the adsorption tower 100, the low-temperature flue gas is adsorbed by the low-temperature adsorbent after heat exchange in the adsorption module 120 to become low-temperature clean flue gas, and then flows upward into the heat exchange module 130 to exchange heat with the incoming high-temperature adsorbent. The cooled adsorbent becomes the low-temperature adsorbent; the high-temperature adsorbent entering from the first feed port 111 exchanges heat with the low-temperature clean flue gas in the heat exchange module 130, flows downward into the adsorption module 120 for adsorption, and is finally discharged from the first discharge port 112 at the bottom;

[0080] The clean flue gas after heat exchange is discharged from the adsorption tower 100 through the flue gas outlet 114, and the adsorbent discharged from the first discharge port 112 is transported to the regeneration tower 200 for heating and regeneration;

[0081] The regeneration process includes:

[0082] Preheating step: In the preheating section 220 , the adsorbent entering the regeneration tower 200 through the second feed inlet 211 is preheated to 100 degrees Celsius;

[0083] Heating step: In the heating section 230, the preheated adsorbent is heated to 300 degrees Celsius to desorb and regenerate the adsorbent, and the regenerated gas is output from the regeneration tower 200;

[0084] Cooling step: In the cooling section 240, the low-temperature clean flue gas discharged from the adsorption tower 100 through the flue gas outlet 114 cools the regenerated adsorbent to 100 degrees Celsius;

[0085] The cooled adsorbent is fed into the adsorption tower 100 through the first feed port 111 .

[0086] In order to further recycle the cold energy in the flue gas, in the embodiment of the present disclosure, as shown in FIG1 , a material transport device 300 is provided between the first feed port 111 of the adsorption tower 100 and the second discharge port 212 of the regeneration tower 200. The material transport device 300 is used to transport the regenerated adsorbent to the adsorption tower 100. The material transport device 300 includes a cooling air inlet 311 and a cooling air outlet 312. The adsorption regeneration process further includes:

[0087] The low-temperature clean flue gas flowing out of the flue gas outlet 114 of the adsorption tower 100 is input into the material transport device through the cooling gas inlet 311 . The low-temperature clean flue gas circulates in the material transport device 300 and contacts the adsorbent to cool the adsorbent, and is then discharged from the cooling gas outlet 312 .

[0088] Specifically, as shown in Figure 1 , the material transport device 300 includes a conveyor 310 and a sealed housing 320. The conveyor 310 is located within the sealed housing 320 and is used to transport the regenerated adsorbent to the adsorption tower 100 , i.e., the conveyor 110 is used to transport the adsorbent. The sealed housing 320 is provided with a cooling air inlet 311 and a cooling air outlet 312. Low-temperature clean flue gas enters the sealed housing 320 from the cooling air inlet 311 to purge the material and is then discharged from the cooling air outlet 312.

[0089] The regenerated adsorbent discharged from regeneration tower 200 is relatively hot. During transport, it exchanges heat with the low-temperature clean flue gas circulating within sealed enclosure 320, minimizing the temperature of the adsorbent entering adsorption tower 100 to approach that of the low-temperature flue gas, thereby effectively improving adsorption efficiency. Simultaneously, the low-temperature clean flue gas removes any contaminants that may be present in the sealed enclosure, effectively preventing contamination of the adsorbent during transport.

[0090] Since the adsorbent is further cooled by heat exchange with the low-temperature clean flue gas during transportation before entering the adsorption tower 100, the cooling load of the cooling section 240 of the regeneration tower 200 is also reduced, thereby reducing the structural complexity and regeneration cost of the regeneration tower 200.

[0091] In the description of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present disclosure.

[0092] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. Throughout the present disclosure, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0093] In this disclosure, unless otherwise expressly specified or limited, terms such as "mounted," "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections, electrical connections, or communication between them; direct connections or indirect connections through an intermediate medium; and internal communication between two elements or interaction between two elements, unless otherwise expressly limited. Those skilled in the art will understand the specific meanings of the above terms in this disclosure based on specific circumstances.

[0094] In the present disclosure, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0095] In the present disclosure, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0096] Although the embodiments of the present disclosure have been shown and described above, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the present disclosure. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present disclosure.

Claims

1. An adsorption regeneration process for recovering cold energy from low-temperature flue gas, comprising: Adsorption step: low-temperature flue gas with a temperature below room temperature enters the adsorption tower to be adsorbed and purified into clean flue gas by the adsorbent in the adsorption tower; and Regeneration step: heating the adsorbent saturated with adsorption to a high-temperature adsorbent in a regeneration tower to regenerate the adsorbent; The clean flue gas is heat exchanged with the high-temperature adsorbent, and the high-temperature adsorbent is cooled to a low-temperature adsorbent with a reduced temperature, which is transported to the adsorbent bed in the adsorption tower, thereby the low-temperature flue gas entering the adsorption tower is adsorbed and purified into clean flue gas, and the adsorbent that has been saturated with adsorption in the adsorption tower is transported to the regeneration tower for heating and regeneration.

2. The adsorption regeneration process for recovering cold energy of low-temperature flue gas according to claim 1, wherein: The clean flue gas and the high-temperature adsorbent are heat-exchanged in the adsorption tower, and the clean flue gas after the heat exchange is discharged from the adsorption tower from the flue gas outlet.

3. The adsorption regeneration process for recovering cold energy of low-temperature flue gas according to claim 1 or 2, wherein: The low-temperature flue gas flows from bottom to top and is discharged from the adsorption tower after completing adsorption and heat exchange in sequence. The high-temperature adsorbent flows from top to bottom and is discharged from the adsorption tower after completing heat exchange and adsorption in sequence.

4. The adsorption regeneration process for recovering cold energy of low-temperature flue gas according to any one of claims 1 to 3, wherein: In the adsorption step, the low-temperature flue gas and the adsorbent flow in countercurrent or crosscurrent in the adsorption tower.

5. The adsorption regeneration process for recovering cold energy of low-temperature flue gas according to any one of claims 1 to 4, wherein: The temperature of the high-temperature adsorbent is 50 degrees Celsius to 300 degrees Celsius, and the temperature of the low-temperature adsorbent is 0 degrees Celsius to 30 degrees Celsius.

6. The adsorption regeneration process for recovering cold energy of low-temperature flue gas according to any one of claims 1 to 5, wherein: Regeneration of the adsorbent in the regeneration tower includes: A preheating step, preheating the adsorbent entering the regeneration tower to 80 degrees Celsius to 110 degrees Celsius; The heating step heats the preheated adsorbent to 250 degrees Celsius to 350 degrees Celsius to desorb and regenerate the adsorbent.

7. The adsorption regeneration process for recovering cold energy of low-temperature flue gas according to claim 6, wherein: Regenerating the adsorbent in the regeneration tower also includes: a cooling step, using the clean flue gas to cool the regenerated adsorbent to 80 degrees Celsius to 250 degrees Celsius.

8. The adsorption regeneration process for recovering cold energy from low-temperature flue gas according to any one of claims 1 to 7, characterized in that: A material transport device for transporting adsorbent is provided between the feed inlet of the adsorption tower and the discharge outlet of the regeneration tower, and the material transport device includes a cooling air inlet and a cooling air outlet. The adsorption regeneration process further includes: The clean flue gas after heat exchange with the high-temperature adsorbent enters the material transport device through the cooling gas inlet to contact with the adsorbent in the material transport device to cool the adsorbent, and then is discharged from the cooling gas outlet.

9. An adsorption regeneration system, comprising an adsorption tower and a regeneration tower, wherein the adsorption tower has a first feed inlet, a first discharge port, a flue gas inlet and a flue gas outlet, and the regeneration tower has a second feed inlet and a second discharge port, the first discharge port of the adsorption tower is connected to the second feed inlet of the regeneration tower, and the first feed inlet of the adsorption tower is connected to the second discharge port of the regeneration tower, The low-temperature flue gas with a temperature below room temperature enters the adsorption tower through the flue gas inlet, is adsorbed and purified by the adsorbent in the adsorption tower to be discharged from the flue gas outlet, and the adsorbent saturated with adsorption is heated to be a high-temperature adsorbent in the regeneration tower to regenerate the adsorbent; The clean flue gas is heat-exchanged with the high-temperature adsorbent to cool the high-temperature adsorbent into a low-temperature adsorbent with a reduced temperature and transport it to the adsorption tower through the first feed port. The adsorbent that has been saturated with adsorption in the adsorption tower is discharged from the first discharge port and transported to the regeneration tower through the second feed port. The adsorbent that has been regenerated in the regeneration tower is discharged from the second discharge port.

10. The adsorption regeneration system according to claim 9, wherein: The clean flue gas and the high-temperature adsorbent perform heat exchange in the adsorption tower.

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