A regenerative olefin dechlorination absorbent recycling system

Abstract

The application relates to the chemical technology field and provides a circulating system of a renewable olefin dechlorination absorbent, which comprises an absorbent storage tank, an absorption tower and a regeneration tower which are sequentially connected; a filler placing box is arranged in the absorption tower; a hydrogen chloride and olefin mixed gas inlet and a first feeding port are arranged on the side wall of the absorption tower; an olefin gas outlet is arranged at the top of the absorption tower; a first desiccant placing box, a reactant placing box and a second desiccant placing box are sequentially arranged in the regeneration tower from top to bottom; a third feeding port and a nitrogen gas inlet are arranged on the side wall of the regeneration tower; a tail gas outlet is arranged at the top of the regeneration tower; the first feeding port is connected with the absorbent storage tank; and the third feeding port is connected with a bottom discharging port of the absorption tower. The circulating system utilizes the equal division effect of the filler, so that the absorbent can fully absorb hydrogen chloride, thereby guaranteeing the adsorption effect of the hydrogen chloride; the absorbent is dried, chemically reacted to remove chlorine and then dried in the regeneration tower, so that the regeneration and recycling of the absorbent are realized.

Description

Technical Field

[0001] This application belongs to the field of chemical technology, and more specifically, relates to a recycling system for a renewable olefin dechlorination absorbent. Background Technology

[0002] Olefin gases are key raw materials in the petrochemical industry. In the production of products such as polyolefins and propylene oxide, hydrogen chloride in the raw materials needs to be removed (to prevent equipment corrosion and catalyst poisoning). Traditional processes often use disposable absorbents or simple regeneration systems, which are applied to small and medium-sized olefin purification scenarios.

[0003] Traditional processes have significant drawbacks: 1. Poor adsorption effect; 2. Difficult or inefficient regeneration of the absorbent, with high impurity and moisture content after regeneration; 3. Lack of hydrogen monitoring when using specific elements, incomplete tail gas treatment, waste of byproducts, and inaccurate selection of absorption tower materials and lack of desiccant, resulting in unstable dechlorination effect; 4. To achieve a hydrogen chloride content of less than 0.5%, the desorption process requires prolonged cyclic heating of the absorbent, which easily generates byproducts that are not conducive to the reuse of the absorbent. Utility Model Content

[0004] In view of one of the shortcomings of the prior art, the purpose of this application is to provide a recycling system for a renewable olefin dechlorination absorbent, which can effectively recycle the absorbent.

[0005] To achieve the above objectives, the technical solution adopted in this application is: to provide a circulation system for a regenerable olefin dechlorination absorbent, comprising: an absorbent storage tank, an absorption tower, and a regeneration tower connected in sequence;

[0006] The absorption tower is equipped with a first inner grid, and a packing box is provided on the first inner grid. The side wall of the absorption tower is provided with a hydrogen chloride and olefin mixed gas inlet and a first feed inlet. The top of the absorption tower is provided with an olefin gas outlet. The position of the hydrogen chloride and olefin mixed gas inlet is lower than the height of the first inner grid, and the position of the first feed inlet is higher than the height of the packing box.

[0007] The regeneration tower is equipped with a second inner grid, on which, from top to bottom, are arranged a first desiccant placement box, a reactant placement box, and a second desiccant placement box.

[0008] The regeneration tower has a third feed inlet and a nitrogen inlet on its side wall. The top of the regeneration tower has a tail gas outlet containing hydrogen and nitrogen. The third feed inlet is located above the height of the first desiccant placement box, and the nitrogen inlet is located below the height of the second inner grid.

[0009] The first inlet is connected to the absorbent storage tank, and the third inlet is connected to the bottom outlet of the absorption tower.

[0010] In one embodiment, the bottom of the absorbent storage tank is connected to the first inlet via a first pipe, and a first pump is installed on the first pipe.

[0011] In one embodiment, the bottom outlet of the absorption tower is connected to the third inlet via a second pipe, and a second pump is installed on the second pipe.

[0012] In one embodiment, a second feed inlet is provided on the side wall of the absorption tower. The second feed inlet is at the same horizontal position as the first feed inlet, and the second feed inlet is connected to the second pipe through a fourth pipe.

[0013] In one embodiment, the absorption tower is further provided with a first liquid distributor, which is located below the first feed inlet and the second feed inlet and above the packing placement box.

[0014] In one embodiment, a fourth feed inlet is provided on the side wall of the regeneration tower, and a third pipe is connected to the bottom outlet of the regeneration tower. The third pipe is connected to the top of the absorbent storage tank. The fourth feed inlet and the third feed inlet are at the same horizontal position. The fourth feed inlet is connected to the third pipe through a fifth pipe.

[0015] In one embodiment, the regeneration tower is further provided with a second liquid distributor, which is located below the third and fourth feed inlets and above the first desiccant placement box.

[0016] In one embodiment, the third pipeline is equipped with a third pump and a heat exchanger.

[0017] In one embodiment, both the fourth and fifth pipes are equipped with valves.

[0018] In one embodiment, the regeneration tower is equipped with a hydrogen concentration monitoring device.

[0019] The beneficial effects of the regenerable olefin dechlorination absorbent circulation system provided in this application are as follows: the mixed gas is first dispersed through the first inner grid before entering the packing box. The absorbent and hydrogen chloride are in full contact with the olefin mixed gas in the packing box, so that the absorbent can fully absorb the hydrogen chloride in the mixed gas, ensuring the adsorption effect of hydrogen chloride; the absorbent with adsorbed hydrogen chloride is dried and chemically reacted in the regeneration tower to remove the hydrogen chloride, and then dried again to ensure the dechlorination effect of the absorbent, so that the absorbent basically returns to its initial state (hydrogen chloride content is less than 0.5%), realizing the regeneration and reuse of the absorbent; the hydrogen concentration in the regeneration tower is monitored by a hydrogen concentration monitoring device, and the hydrogen concentration in the regeneration tower is reduced by introducing nitrogen gas, ensuring the safe operation of the regeneration tower. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 A schematic diagram of the connection structure of the circulation system for the renewable olefin dechlorination absorbent provided in the embodiments of this application;

[0022] Figure 2 A schematic diagram of the internal structural layout of the absorption tower in the circulation system of the renewable olefin dechlorination absorbent provided in the embodiments of this application;

[0023] Figure 3 This is a schematic diagram of the internal structural layout of the regeneration tower in the circulation system of the regenerable olefin dechlorination absorbent provided in the embodiments of this application.

[0024] The following are the labeling elements in the figure:

[0025] 11. Absorbent storage tank; 12. Absorption tower; 13. Regeneration tower; 14. First pump; 15. Second pump; 16. Third pump; 17. Heat exchanger; 18. Packing box; 19. First desiccant box; 20. Reactant box; 21. Second desiccant box; 22. Hydrogen concentration monitoring device; 110. First feed inlet; 111. Hydrogen chloride and olefin mixture inlet; 112. Second feed inlet; 113. First liquid distributor; 114. First inner grid; 115. Olefin outlet; 120. Third feed inlet; 121. Nitrogen inlet; 122. Fourth feed inlet; 123. Second liquid distributor; 124. Second inner grid; 125. Tail gas outlet. Detailed Implementation

[0026] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0027] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0028] It should be understood that the terms "length", "width", "upper", "lower", "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. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0029] 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 indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0030] like Figures 1-3 As shown, a regenerable olefin dechlorination absorbent circulation system provided in this application embodiment will now be described. This regenerable olefin dechlorination absorbent circulation system includes an absorbent storage tank 11, an absorption tower 12, and a regeneration tower 13 connected in sequence. The absorbent storage tank 11 stores absorbents that are hydrochloric acid-loving to olefins, such as glycerol and polyethylene glycol. The absorption tower 12 adsorbs hydrogen chloride from the mixed gas through hydrogen bonding between the absorbent and hydrogen chloride, achieving deep separation of hydrogen chloride and olefins. The regeneration tower 13 allows the absorbent that has adsorbed hydrogen chloride to react with reactants, removing residual hydrogen chloride and regenerating the absorbent.

[0031] Specifically, the absorption tower 12 is provided with a first inner grid 114, and a packing box 18 is provided on the first inner grid 114. The side wall of the absorption tower 12 is provided with a hydrogen chloride and olefin mixed gas inlet 111 and a first feed inlet 110. The top of the absorption tower 12 is provided with an olefin gas outlet 115. The position of the hydrogen chloride and olefin mixed gas inlet 111 is lower than the height of the first inner grid 114, and the position of the first feed inlet 110 is higher than the height of the packing box 18. The first feed inlet 110 is connected to the absorbent storage tank 11. The absorbent in the absorbent storage tank 11 enters the absorption tower 12 through the first feed port 110 and then enters the packing box 18. The hydrogen chloride and olefin mixture enters the absorption tower 12 through the hydrogen chloride and olefin mixture inlet 111. The mixture first passes through the first inner grid 114 to disperse the mixture, and then enters the packing box 18. The two are then fully mixed and contacted by the packing in the packing box 18, so that the absorbent adsorbs the hydrogen chloride in the mixture. The olefins that have been dechlorinated are discharged and collected through the olefin outlet 115 at the top.

[0032] The regeneration tower 13 is equipped with a second inner grid 124. The second inner grid 124 is provided with a first desiccant placement box 19, a reactant placement box 20 and a second desiccant placement box 21 arranged sequentially from top to bottom. The side wall of the regeneration tower 13 is provided with a third feed inlet 120 and a nitrogen inlet 121. The top of the regeneration tower 13 is provided with a tail gas outlet 125 for discharging hydrogen and nitrogen. The position of the third feed inlet 120 is higher than the height of the first desiccant placement box 19, and the position of the nitrogen inlet 121 is lower than the height of the second inner grid 124. The third feed inlet 120 is connected to the bottom outlet of the absorption tower 12. The absorbent containing adsorbed hydrogen chloride in the absorption tower 12 enters the regeneration tower 13 through the third feed inlet 120. It first undergoes initial drying in the first desiccant placement box 19 to remove moisture. Then, it passes through the reactant placement box 20, where reactants react with residual hydrogen chloride in the absorbent to dechlorinate it. Finally, it undergoes further drying in the second desiccant placement box 21. The regenerated absorbent can then be returned to the absorbent storage tank 11 for reuse. Specifically, the regeneration tower 13 is also equipped with a hydrogen concentration monitoring device 22 to monitor the concentration of hydrogen generated during the reaction. If the hydrogen concentration exceeds a predetermined value, a nitrogen supply device discharges nitrogen into the regeneration tower 13 through the nitrogen inlet 121, thereby carrying the hydrogen out of the regeneration tower 13 and reducing the hydrogen concentration within it.

[0033] Specifically, the bottom of the absorbent storage tank 11 is connected to the first inlet 110 via a first pipe, and a first pump 14 is installed on the first pipe. The first pump 14 is used to pump the absorbent into the absorption tower 12. Similarly, the bottom outlet of the absorption tower 12 is connected to the third inlet 120 via a second pipe, and a second pump 15 is installed on the second pipe. The second pump 15 is used to pump the absorbent containing hydrogen chloride into the regeneration tower 13.

[0034] Preferably, the absorption tower 12 has a second inlet 112 on its side wall, which is at the same horizontal level as the first inlet 110. The second inlet 112 is connected to the second pipe via a fourth pipe, so that the absorbent discharged from the bottom of the absorption tower 12 can re-enter the absorption tower 12 through the fourth pipe and the second inlet 112 to adsorb hydrogen chloride in the mixed gas and improve the saturation of the absorbent for hydrogen chloride absorption. Similarly, the regeneration tower 13 has a fourth inlet 122 on its side wall, and the bottom outlet of the regeneration tower 13 is connected to a third pipe, which is connected to the top of the absorbent storage tank 11 for recycling the absorbent. The fourth inlet 122 is at the same horizontal level as the third inlet 120, and the fourth inlet 122 is connected to the third pipe via a fifth pipe, so that the absorbent discharged from the bottom of the regeneration tower 13 can re-enter the regeneration tower 13 through the fifth pipe and the fourth inlet 122 to further remove residual hydrogen chloride in the absorbent. Specifically, valves are installed on both the fourth and fifth pipelines. These valves are used to control the proportion and flow of absorbent back into the absorption tower 12 and the regeneration tower 13.

[0035] To ensure uniform distribution of the absorbent, the absorption tower 12 is also equipped with a first liquid distributor 113. The first liquid distributor 113 is located below the first inlet 110 and the second inlet 112, and above the packing placement box 18. The first liquid distributor 113 is used to uniformly disperse the absorbent entering through the first inlet 110 and the second inlet 112 and allow it to flow into the packing placement box 18, ensuring sufficient contact between the absorbent and the packing material. Similarly, to ensure uniform distribution of the absorbent, the regeneration tower 13 is also equipped with a second liquid distributor 123. The second liquid distributor 123 is located below the third inlet 120 and the fourth inlet 122, and above the first desiccant placement box 19. The second liquid distributor 123 is used to uniformly disperse the absorbent entering through the third inlet 120 and the fourth inlet 122 and allow it to flow into the first desiccant placement box 19, ensuring sufficient contact between the absorbent and the desiccant to remove moisture.

[0036] The third pipeline is equipped with a third pump 16 and a heat exchanger 17. The third pump 16 is used to discharge the absorbent discharged from the bottom of the regeneration tower 13 into the absorbent storage tank 11. Before entering the absorbent storage tank 11, the absorbent passes through the heat exchanger 17 to exchange heat and cool it down, so as to prevent the heat generated when the reactants react with hydrogen chloride from heating the absorbent for a long time and avoiding the generation of unwanted by-products.

[0037] In this embodiment, the absorbent stored in absorbent storage tank 11 is a liquid absorbent such as glycerol or polyethylene glycol that is hydroxyl-rich and hydrochloric acid-loving. The packing material in packing box 18 is ceramic ring packing. The reactants in reactant box 20 can be elemental metals such as magnesium, aluminum, zinc, iron, tin, etc.; metal oxides such as magnesium oxide, calcium oxide, zinc oxide, etc.; metal hydroxides such as magnesium hydroxide, calcium hydroxide, aluminum hydroxide, etc.; or carbonates such as calcium carbonate, sodium bicarbonate, magnesium carbonate, etc. All reactants can react with residual hydrogen chloride in the chlorine-containing absorbent to remove hydrogen chloride. The desiccants in the first desiccant box 19 and the second desiccant box 21 are solid desiccants, such as 3A molecular sieves or modified silica gel, used to absorb moisture, ensuring the water content in the absorbent is less than 500 ppm. In this embodiment, both the absorption tower 12 and the regeneration tower 13 have detachable tower covers. The tower covers are sealed by a ring of bolts and a sealing ring. The first liquid distributor 113, the packing box 18, the second liquid distributor 123, the first desiccant box 19, the reactant box 20, and the second desiccant box 21 are all disassembled and assembled by hoisting.

[0038] In this embodiment, the hydrogen concentration in the regeneration tower 13 can be monitored in real time by the hydrogen concentration monitoring device 22. When the hydrogen content is detected to be >1%, the nitrogen inlet 121 is opened and the nitrogen supply device provides nitrogen. The nitrogen is then used for purging to ensure the safe operation of the regeneration tower 13.

[0039] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A recycling system for a renewable olefin dechlorination absorbent, characterized in that, include: The absorbent storage tank (11), the absorption tower (12), and the regeneration tower (13) are connected in sequence; The absorption tower (12) is provided with a first inner grid (114), and a packing box (18) is provided on the first inner grid (114). The side wall of the absorption tower (12) is provided with a hydrogen chloride and olefin mixed gas inlet (111) and a first feed inlet (110). The top of the absorption tower (12) is provided with an olefin gas outlet (115). The position of the hydrogen chloride and olefin mixed gas inlet (111) is lower than the height of the first inner grid (114), and the position of the first feed inlet (110) is higher than the height of the packing box (18). The regeneration tower (13) is equipped with a second inner grid (124), on which a first desiccant placement box (19), a reactant placement box (20), and a second desiccant placement box (21) are arranged sequentially from top to bottom. The regeneration tower (13) is provided with a third feed inlet (120) and a nitrogen inlet (121) on its side wall. The top of the regeneration tower (13) is provided with a tail gas outlet (125) that discharges hydrogen and nitrogen. The position of the third feed inlet (120) is higher than the height of the first desiccant placement box (19), and the position of the nitrogen inlet (121) is lower than the height of the second inner grid (124). The first feed inlet (110) is connected to the absorbent storage tank (11), and the third feed inlet (120) is connected to the bottom outlet of the absorption tower (12).

2. The recycling system for the renewable olefin dechlorination absorbent as described in claim 1, characterized in that: The bottom of the absorbent storage tank (11) is connected to the first inlet (110) via a first pipe, and a first pump (14) is provided on the first pipe.

3. The recycling system for the renewable olefin dechlorination absorbent as described in claim 2, characterized in that: The bottom outlet of the absorption tower (12) is connected to the third inlet (120) via a second pipe, and a second pump (15) is installed on the second pipe.

4. The recycling system for the renewable olefin dechlorination absorbent as described in claim 3, characterized in that: The absorption tower (12) has a second feed inlet (112) on its side wall. The second feed inlet (112) is at the same horizontal position as the first feed inlet (110). The second feed inlet (112) is connected to the second pipe through a fourth pipe.

5. The recycling system for the renewable olefin dechlorination absorbent as described in claim 4, characterized in that: The absorption tower (12) is also equipped with a first liquid distributor (113), which is located below the first feed inlet (110) and the second feed inlet (112) and above the packing placement box (18).

6. The recycling system for the renewable olefin dechlorination absorbent as described in claim 5, characterized in that: The regeneration tower (13) is provided with a fourth feed port (122) on its side wall. The bottom outlet of the regeneration tower (13) is connected to a third pipe. The third pipe is connected to the top of the absorbent storage tank (11). The fourth feed port (122) and the third feed port (120) are at the same horizontal position. The fourth feed port (122) is connected to the third pipe through a fifth pipe.

7. The recycling system for the renewable olefin dechlorination absorbent as described in claim 6, characterized in that: The regeneration tower (13) is also equipped with a second liquid distributor (123), which is located below the third feed inlet (120) and the fourth feed inlet (122) and above the first desiccant placement box (19).

8. The recycling system for the renewable olefin dechlorination absorbent as described in claim 7, characterized in that: The third pipeline is equipped with a third pump (16) and a heat exchanger (17).

9. The recycling system for the renewable olefin dechlorination absorbent as described in claim 7, characterized in that: Valves are installed on both the fourth and fifth pipes.

10. The recycling system for the regenerable olefin dechlorination absorbent as described in any one of claims 1-9, characterized in that: The regeneration tower (13) is equipped with a hydrogen concentration monitoring device (22).

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