Energy-saving regenerated gas recirculation system

Abstract

The utility model relates to the technical field of reforming regeneration, in particular to an energy-saving regenerated gas recirculation system, which is characterized in that an oxychlorination area is connected with an oxychlorination feeding pipeline, a roasting feeding pipeline and a regenerated gas outlet pipeline, and the oxychlorination feeding pipeline is connected with a water injection pipeline and a chlorine injection pipeline; the second-section charring area is connected with a second-section inlet pipeline and a second-section outlet pipeline; the compressor recycling unit comprises a circulating gas inlet pipeline led out from a regenerated gas outlet pipeline, a compressor connected with the circulating gas inlet pipeline, a first circulating gas outlet pipeline connected to the oxychlorination feeding pipeline from an outlet of the compressor, and a second circulating gas outlet pipeline connected to the two-section inlet pipeline from an outlet of the compressor; a first regulating valve is arranged on the circulating air inlet pipeline, a second regulating valve is arranged on the first circulating air outlet pipeline, and a third regulating valve is arranged on the second circulating air outlet pipeline. The oxygen content in the regenerator can be improved, and the platinum dispersity is further improved.

Description

Technical Field

[0001] The utility model relates to the technical field of reforming regeneration, in particular to an energy-saving regeneration gas recycling system. Background Art

[0002] The catalyst generally comprises a carrier, at least one noble metal, at least one halogen or other added element. For example, a platinum-containing metal is deposited on an aluminum oxychloride carrier. Such catalysts reform aromatic compounds or prepare aromatic compounds by dehydrogenation cyclization and / or dehydrogenation, such as continuous reforming catalysts.

[0003] During the continuous reforming reaction, platinum metal will aggregate on the catalyst, affecting the catalyst effect. When the catalyst is regenerated, the chlorine element on the carrier will be lost after the charring treatment. An oxychlorination step is required to adjust the chlorine content on the catalyst and fully oxidize and disperse the metal on the catalyst to restore the catalyst activity.

[0004] However, the oxychlorination / roasting gas goes directly to the alkali washing tank for alkali washing of the chlorine-containing gas. This process consumes tetrachloroethylene and liquid alkali, and the regeneration system uses a large amount of liquid alkali and tetrachloroethylene. The supplementary gas in the second-stage coking zone is normal temperature industrial air, and the supplementary gas temperature is about 18°C-25°C, which affects the temperature of the second-stage coking zone. The oxygen content in the second-stage coking zone is about 0.8%, the oxygen content at the oxychlorination outlet is about 4%-6%, and the oxygen content at the oxychlorination inlet is about 8-12%. The low oxygen content affects the dispersion of platinum and reduces the catalyst performance. Utility Model Content

[0005] In view of the defects of the prior art, the utility model provides an energy-saving regeneration gas recycling system, which compresses the chlorine-containing gas at the oxychlorination outlet and divides it into two paths. One path of chlorine-containing gas replaces the original factory air to supplement the air for the second-stage charring; the other path of chlorine-containing gas returns to the oxychlorination inlet to reduce the use of tetrachloroethylene and liquid alkali, while increasing the oxygen content in the regenerator, thereby improving the dispersion of platinum.

[0006] In order to achieve the above-mentioned purpose, the technical solution provided by the utility model is an energy-saving regeneration gas recycling system, which includes an oxychlorination zone, a second-stage charring zone and a compressor recycling unit; the oxychlorination zone is connected to an oxychlorination feed pipeline, a roasting feed pipeline and a regeneration gas outlet pipeline, and the oxychlorination feed pipeline is connected to a water injection pipeline and a chlorine injection pipeline; the second-stage charring zone is connected to a second-stage inlet pipeline and a second-stage outlet pipeline; the compressor recycling unit includes a circulating air inlet pipeline led out from the regeneration gas outlet pipeline, a compressor connected to the circulating air inlet pipeline, a first circulating air outlet pipeline connected to the oxychlorination feed pipeline by the outlet of the compressor, and a second circulating air outlet pipeline connected to the second-stage inlet pipeline by the outlet of the compressor; a first regulating valve is provided on the circulating air inlet pipeline, a second regulating valve is provided on the first circulating air outlet pipeline, and a third regulating valve is provided on the second circulating air outlet pipeline.

[0007] Furthermore, a first gate valve is provided on the circulating air intake pipeline and upstream of the first regulating valve.

[0008] Furthermore, the regeneration gas outlet pipeline is connected to a primary heat exchanger, and the primary heat exchanger is connected to an inlet pipeline of a secondary heat exchanger.

[0009] Furthermore, a cross-line air intake pipeline is connected on the circulating air intake pipeline and between the first gate valve and the first regulating valve, and the cross-line air intake pipeline is connected to the downstream of the first-stage heat exchanger.

[0010] Furthermore, a second gate valve is provided on the cross-line air intake pipeline.

[0011] Furthermore, the normal temperature industrial air pipeline is connected to the second-stage inlet pipeline through a first branch pipe; the normal temperature industrial air pipeline is connected to the oxychlorination feed pipeline through a second branch pipe, and the normal temperature industrial air pipeline is connected to the roasting feed pipeline through a third branch pipe.

[0012] Furthermore, an industrial air heat exchanger is provided on the normal temperature industrial air pipeline and upstream of the meeting point of the normal temperature industrial air pipeline and the roasting feed pipeline.

[0013] Furthermore, the first branch pipe, the second branch pipe and the third branch pipe are respectively provided with a first air volume regulating valve, a second air volume regulating valve and a third air volume regulating valve.

[0014] The utility model has the following beneficial effects: after the transformation, the supplementary gas temperature is increased from 18°C ​​to 400°C, which can increase the temperature of the second-stage charring zone; the oxygen content of the regenerated gas is low before the transformation, and after the transformation, the oxygen content of the second-stage charring zone is increased from 0.8% to 4-6%, the oxygen content at the oxychlorination outlet is increased from 4-6% to 15-21%, and the oxygen content at the oxychlorination inlet is increased from 8-12% to 15-21%, which can increase the oxygen content in the oxychlorination zone and promote platinum dispersion, thereby improving the catalyst performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A process flow chart of an energy-saving regeneration gas recycling system in one embodiment of the invention;

[0016] In the figure:

[0017] 100, oxychlorination zone, 110, oxychlorination feed pipeline, 120, roasting feed pipeline, 130, regeneration gas outlet pipeline, 140, water injection pipeline, 150, chlorine injection pipeline,

[0018] 200, the second section of the scorched area, 210, the second section of the inlet pipeline, 220, the second section of the outlet pipeline,

[0019] 300, compressor recirculation unit, 310, circulating air inlet pipeline, 311, first regulating valve, 312, first gate valve, 320, compressor, 330, first circulating air outlet pipeline, 331, second regulating valve, 340, second circulating air outlet pipeline, 341, third regulating valve, 350, cross-line air inlet pipeline, 351, second gate valve,

[0020] 400, primary heat exchanger,

[0021] 500, secondary heat exchanger inlet pipeline,

[0022] 600, normal temperature industrial air pipeline, 610, first branch pipe, 611, first air volume regulating valve, 620, second branch pipe, 621, second air volume regulating valve, 630, third branch pipe, 631, third air volume regulating valve,

[0023] 700. Industrial air heat exchanger. DETAILED DESCRIPTION

[0024] In order to make the above-mentioned purposes, features and advantages of the utility model more obvious and easy to understand, the specific implementation methods of the utility model are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the utility model. However, the utility model can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the utility model, so the utility model is not limited by the specific embodiments disclosed below.

[0025] See also Figure 1, shows an energy-saving regeneration gas recycling system in one embodiment of the present invention, which includes an oxychlorination zone 100, a second-stage charring zone 200 and a compressor recycling unit 300; the oxychlorination zone 100 is connected to an oxychlorination feed pipeline 110, a roasting feed pipeline 120 and a regeneration gas outlet pipeline 130, and the oxychlorination feed pipeline 110 is connected to a water injection pipeline 140 and a chlorine injection pipeline 150; the second-stage charring zone 200 is connected to a second-stage inlet pipeline 210 and a second-stage outlet pipeline 220; the compressor recycling unit 300 includes a regeneration gas recycle unit 110, a second-stage charring zone 200, and ... A circulating air inlet pipeline 310 led out from the gas outlet pipeline 130, a compressor 320 connected to the circulating air inlet pipeline 310, a first circulating air outlet pipeline 330 connected to the oxychlorination feed pipeline 110 by the outlet of the compressor 320, and a second circulating air outlet pipeline 340 connected to the second-stage inlet pipeline 210 by the outlet of the compressor 320; a first regulating valve 311 is provided on the circulating air inlet pipeline 310, a second regulating valve 331 is provided on the first circulating air outlet pipeline 330, and a third regulating valve 341 is provided on the second circulating air outlet pipeline 340.

[0026] The energy-saving regeneration gas recycling system converts the chlorine-containing gas at the outlet of the oxychlorination zone from the regeneration gas outlet pipeline 130, and is compressed by the compressor 320 and then divided into two paths. One path of chlorine-containing gas is used to supplement the air for the second stage of charring, and the other path of chlorine-containing gas returns to the oxychlorination inlet, which can increase the regeneration oxygen content while reducing the amount of water and chlorine injected into the oxychlorination, thereby increasing the dispersion of platinum. The first regulating valve 311 can be remotely controlled, and the inlet flow of the regeneration gas recirculation compressor 320 can be controlled by an internal operator; the second regulating valve 331 can be remotely controlled, and the oxygen content of the second stage inlet can be controlled by an internal operator; the third regulating valve 341 can be remotely controlled, and the flow of the regeneration gas to the oxychlorination inlet can be controlled by an internal operator.

[0027] In one embodiment, a first gate valve 312 is disposed on the circulating air intake line 310 and upstream of the first regulating valve 311 .

[0028] In one embodiment, the regeneration gas outlet pipeline 130 is connected to the primary heat exchanger 400 , and the primary heat exchanger 400 is connected to a secondary heat exchanger inlet pipeline 500 .

[0029] In one embodiment, a cross-line air intake line 350 is connected to the circulating air intake line 310 between the first gate valve 312 and the first regulating valve 311 , and the cross-line air intake line 350 is connected to the downstream of the primary heat exchanger 400 .

[0030] In one embodiment, a second gate valve 351 is disposed on the cross-line air intake line 350 .

[0031] In one embodiment, the normal temperature industrial air pipeline 600 is connected to the second-stage inlet pipeline 210 through a first branch pipe 610; the normal temperature industrial air pipeline 600 is connected to the oxychlorination feed pipeline 110 through a second branch pipe 620; and the normal temperature industrial air pipeline 600 is connected to the roasting feed pipeline 120 through a third branch pipe 630.

[0032] In one embodiment, an industrial air heat exchanger 700 is provided on the normal temperature industrial air pipeline 600 and upstream of the meeting point of the normal temperature industrial air pipeline 600 and the roasting feed pipeline 120 .

[0033] In one embodiment, a first air volume regulating valve 611 , a second air volume regulating valve 621 , and a third air volume regulating valve 631 are respectively disposed on the first branch pipe 610 , the second branch pipe 620 , and the third branch pipe 630 .

[0034] Regeneration gas recycling modification content and description:

[0035] The pipe inlet pipeline of the first-stage heat exchanger 400 is changed to a tee. After the tee, a first gate valve 312 is added to the original regeneration gas pipeline (DN150PN5.0). After the tee, another new pipeline (DN150 PN5.0) is led out to the inlet of the compressor 320 for regeneration gas recycling, and a second gate valve 351 is added to the pipeline (DN150 PN5.0). After the newly added second gate valve 351, a first regulating valve 311 is added to control the air intake at the inlet of the compressor 320. A pipeline (DN150 PN5.0) is led out from the outlet pipeline of the first-stage heat exchanger 400 to the inlet of the newly added regenerated gas recirculation compressor 320; a pipeline (DN80, PN5.0) is led out from the outlet of the newly added compressor 320 to the air supply valve at the second-stage charring inlet, and a second regulating valve 331 is added to the pipeline to adjust the oxygen content at the second-stage inlet; a pipeline (DN150, PN5.0) is led out from the outlet of the newly added compressor 320 to the oxychlorination inlet, and a third regulating valve 341 is added to adjust the circulation volume of the oxychlorination inlet.

[0036] In the description of the present invention, 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 invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0037] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0038] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present utility model, unless otherwise clearly specified and limited, the first feature "above" or "below" the second feature may be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "above" and "above" the second feature may be that the first feature is directly above or obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. The first feature "below", "below" and "below" the second feature may be that the first feature is directly below or obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature. It should be noted that when an element is referred to as "fixed to" or "set on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation method.

Claims

1. An energy-saving regeneration gas recycling system, characterized in that: include The oxychlorination zone is connected with an oxychlorination feed pipeline, a roasting feed pipeline and a regeneration gas outlet pipeline, wherein the oxychlorination feed pipeline is connected with a water injection pipeline and a chlorine injection pipeline; The second scorching zone is connected with a second inlet pipeline and a second outlet pipeline; as well as The compressor recirculation unit comprises a circulating air inlet pipeline led out from the regeneration gas outlet pipeline, a compressor connected to the circulating air inlet pipeline, a first circulating air outlet pipeline connected to the oxychlorination feed pipeline from the outlet of the compressor, and a second circulating air outlet pipeline connected to the second-stage inlet pipeline from the outlet of the compressor; a first regulating valve is provided on the circulating air inlet pipeline, a second regulating valve is provided on the first circulating air outlet pipeline, and a third regulating valve is provided on the second circulating air outlet pipeline.

2. The energy-saving regeneration gas recycling system according to claim 1 is characterized in that: A first gate valve is disposed on the circulating air intake pipeline and upstream of the first regulating valve.

3. The energy-saving regeneration gas recycling system according to claim 2, characterized in that: The regeneration gas outlet pipeline is connected to the primary heat exchanger, and the primary heat exchanger is connected to the secondary heat exchanger inlet pipeline.

4. The energy-saving regeneration gas recycling system according to claim 3 is characterized in that: A cross-line air intake pipeline is connected on the circulating air intake pipeline and between the first gate valve and the first regulating valve, and the cross-line air intake pipeline is connected to the downstream of the primary heat exchanger.

5. The energy-saving regeneration gas recycling system according to claim 4 is characterized in that: A second gate valve is arranged on the cross-line air intake pipeline.

6. An energy-saving regeneration gas recycling system according to any one of claims 1 to 5, characterized in that: The normal temperature industrial air pipeline is connected to the second-stage inlet pipeline through the first branch pipe; the normal temperature industrial air pipeline is connected to the oxychlorination feed pipeline through the second branch pipe, and the normal temperature industrial air pipeline is connected to the roasting feed pipeline through the third branch pipe.

7. The energy-saving regeneration gas recycling system according to claim 6, characterized in that: An industrial air heat exchanger is arranged on the normal temperature industrial air pipeline and upstream of the meeting point of the normal temperature industrial air pipeline and the roasting feed pipeline.

8. The energy-saving regeneration gas recycling system according to claim 6, characterized in that: The first branch pipe, the second branch pipe and the third branch pipe are respectively provided with a first air volume regulating valve, a second air volume regulating valve and a third air volume regulating valve.

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