Fixed bed adsorbent regeneration closed circulation system

Abstract

The utility model provides a closed circulating system for fixed bed adsorbent regeneration, belongs to the technical field of fixed bed adsorbent regeneration, and solves the problems of high nitrogen consumption and no environmental protection in the prior art. The device comprises a C4 processor, the bottom of the C4 processor is connected with a buffer tank through a pipeline, the buffer tank is connected with an air blower through a pipeline, an outlet of the air blower is communicated with a heating pipeline and a cooling pipeline, a heater is arranged in the heating pipeline, and a first cooler is arranged in the cooling pipeline. And the heating pipeline and the cooling pipeline are connected with a nitrogen circulating pipe communicated with the top of the C4 processor. Impurities move to the buffer tank along with nitrogen, most impurities are deposited in the buffer tank, under the driving of the air blower, the nitrogen can selectively enter the heating pipeline or the cooling pipeline and finally returns to the C4 processor through the nitrogen circulating pipe to be repeatedly used, and therefore circulating closed regeneration treatment is achieved, nitrogen loss is reduced, and the service life of the nitrogen is prolonged. And harmful effects of lots of combustion impurities of the torch on environment protection are avoided.

Description

Technical Field

[0001] The utility model belongs to the technical field of fixed bed adsorbent regeneration, in particular to a fixed bed adsorbent regeneration closed circulation system. Background Art

[0002] At present, most of the olefin conversion units (OCU units) in the petrochemical industry use LUMMUS's OCT process technology for the disproportionation reaction of butene and ethylene to produce polymerization-grade propylene. Some of the process raw materials contain pentene in addition to butene. C4 and C5 are mixed and controlled under appropriate reaction conditions and proprietary catalyst (OCT catalyst) technology to react olefins in C4 / C5 with ethylene to produce high-purity propylene.

[0003] In the OCT process, the C4 processor is required to perform adsorption treatment on the C4 and C5 raw materials to remove toxic substances in the C4 and C5 raw materials and prevent catalyst poisoning. When the C4 processor adsorbs to a certain extent, the C4 processor needs to be cut out and regenerated. In the original design, the regeneration treatment of the C4 processor is to pass fresh nitrogen into the C4 processor and purge the adsorption bed in the C4 processor, so as to blow impurities (i.e. toxic substances) out of the C4 processor, and the fresh nitrogen carrying impurities is directly discharged to the flare system for combustion treatment, but this operation will increase the consumption of nitrogen and cannot meet the increasingly stringent environmental protection requirements. Utility Model Content

[0004] In view of the above problems, the purpose of the utility model is to provide a fixed bed adsorbent regeneration closed circulation system, nitrogen enters the C4 processor to blow out impurities, the impurities move to the buffer tank with the nitrogen, most of the impurities will be deposited in the buffer tank, driven by the blower, the nitrogen continues to move, can enter the heating pipeline or the cooling pipeline as required, and finally return to the C4 processor through the nitrogen circulation pipe for reuse, thereby realizing a closed circulation regeneration process, reducing the loss of nitrogen, and avoiding the adverse effects on the environment caused by the large-scale combustion of nitrogen carrying impurities by the flare.

[0005] The technical solution adopted by the utility model is as follows:

[0006] A fixed bed adsorbent regeneration closed circulation system comprises a C4 processor, wherein the bottom of the C4 processor is connected to a buffer tank via a pipeline, the buffer tank is connected to a blower via a pipeline, the outlet of the blower is connected to a heating pipeline and a cooling pipeline, a heater is provided in the heating pipeline, a first cooler is provided in the cooling pipeline, and the heating pipeline and the cooling pipeline are connected to a nitrogen circulation pipe connected to the top of the C4 processor.

[0007] Preferably, a second cooler is provided between the C4 processor and the buffer tank.

[0008] Preferably, a nitrogen replenishing pipe is connected to the pipeline connecting the second cooler and the buffer tank.

[0009] Preferably, a flare delivery pipe is connected to the pipeline connecting the second cooler and the buffer tank.

[0010] Preferably, the heating pipeline and the cooling pipeline are connected to the OCT feed processor and the connection point is located at the top of the OCT feed processor, and the OCT feed processor is connected to the pipeline between the second cooler and the C4 processor through the pipeline.

[0011] Preferably, the heater comprises a steam heater and an electric heater, and the steam heater is located between the electric heater and the blower.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the utility model are:

[0013] Nitrogen enters the C4 processor to purge out impurities. The impurities move to the buffer tank with the nitrogen, and most of the impurities will be deposited in the buffer tank. Driven by the blower, the nitrogen continues to move and can enter the heating pipeline or cooling pipeline as selected, and finally return to the C4 processor through the nitrogen circulation pipe for reuse, thereby realizing a closed circulation regeneration process, reducing the loss of nitrogen, and avoiding the adverse impact of the torch burning a large amount of nitrogen carrying impurities on the environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 A schematic diagram of a flow chart provided for an embodiment of the utility model.

[0016] Description of the drawings: 1-C4 processor; 2-second cooler; 3-nitrogen replenishment pipe; 4-buffer tank; 5-flare delivery pipe; 6-blower; 7-heating pipeline; 8-steam heater; 9-electric heater; 10-cooling pipeline; 11-first cooler; 12-nitrogen circulation pipe; 13-OCT feed processor. DETAILED DESCRIPTION

[0017] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0018] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the present invention, it should be noted that if the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the product of the application is usually placed when used. It is only for the convenience of describing the present invention and simplifying the description, and does 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 cannot be understood as a limitation on the present invention.

[0020] Combine the following Figure 1 The utility model is described in detail.

[0021] Example

[0022] A fixed bed adsorbent regeneration closed circulation system comprises a C4 processor 1, the bottom of the C4 processor 1 is connected to a buffer tank 4 through a pipeline, the buffer tank 4 is connected to a blower 6 through a pipeline, the outlet of the blower 6 is connected to a heating pipeline 7 and a cooling pipeline 10, a heater is provided in the heating pipeline 7, a first cooler 11 is provided in the cooling pipeline 10, and the heating pipeline 7 and the cooling pipeline 10 are connected to a nitrogen circulation pipe 12 connected to the top of the C4 processor 1.

[0023] Nitrogen enters the C4 processor 1 to purge out impurities. The impurities move to the buffer tank 4 with the nitrogen. Most of the impurities will be deposited in the buffer tank 4. Driven by the blower 6, the nitrogen continues to move and can enter the heating pipeline 7 or the cooling pipeline 10 according to the selection. Finally, it returns to the C4 processor 1 through the nitrogen circulation pipe 12 for repeated use. Figure 1As shown, both ends of the nitrogen circulation pipe 12 are provided with relevant control valves to control the opening and closing of the nitrogen circulation pipe 12, wherein the valve provided at one end of the nitrogen circulation pipe 12 close to the heating pipeline 7 and the cooling pipeline 10 is used to select nitrogen to enter the heating pipeline 7 or the cooling pipeline 10; the valve provided at one end of the nitrogen circulation pipe 12 close to the C4 processor 1 is used to control the input of nitrogen, and there are three valves provided there, and a flow regulating valve is provided between the two stop valves.

[0024] The regeneration process includes four stages: cold blowing, heating, constant temperature, and cooling. In the early stage of regeneration, the C4 processor 1 needs to be cold-blown to remove the liquid organic matter adsorbed in the adsorbent. The circulating nitrogen passes through the buffer tank 4 and the blower 6 and enters the cooling pipeline 10. The first cooler 11 in the cooling pipeline 10 can be a water-cooled cooler, which can quickly cool the nitrogen; the cooled nitrogen returns to the C4 processor 1 through the nitrogen circulation pipe 12. The purpose of the heating stage is to use 290°C hot nitrogen to increase the temperature of the adsorbent bed to strip the organic matter in the adsorbent out of the system. The circulating nitrogen passes through the blower 6 and enters the heating pipeline 7. The heater heats the nitrogen, and the heated nitrogen returns to the C4 processor 1 through the nitrogen circulation pipe 12. In the constant temperature stage, the hot nitrogen at 290°C is maintained to continuously strip the organic matter. After the stripping is completed, the temperature is lowered, and the bed temperature after thermal regeneration is reduced to 40°C using normal temperature nitrogen to prepare for the next step of pouring liquid.

[0025] Since the regeneration process requires switching between cold and hot nitrogen, the present application provides a heater and a first cooler 11, which can quickly adjust the temperature of the regeneration gas while ensuring that the flow rate of the regeneration medium remains unchanged, thereby ensuring the stability of the entire regeneration cycle.

[0026] A second cooler 2 is provided between the C4 processor 1 and the buffer tank 4. The second cooler 2 cools down the hot nitrogen coming out of the C4 processor 1 to prevent the blower 6 from being damaged by high temperature.

[0027] A nitrogen replenishing pipe 3 is connected to the pipeline connecting the second cooler 2 and the buffer tank 4. The nitrogen replenishing pipe 3 can replenish nitrogen into the regeneration closed circulation system to make up for the loss of nitrogen; Figure 1 As shown, a flow regulating valve is provided on the nitrogen replenishing pipe 3 to control the replenishing amount of fresh nitrogen. The nitrogen replenishing pipe 3 is located close to the blower 6, so that nitrogen can be replenished in time to avoid surging of the blower 6.

[0028] The pipeline connecting the second cooler 2 and the buffer tank 4 is connected with a flare delivery pipe 5. The flare delivery pipe 5 is connected with the flare system, and can deliver the nitrogen carrying impurities in the regeneration closed circulation system to the flare system for combustion. Figure 1As shown, a flow regulating valve is provided on the flare delivery pipe 5 to adjust the output of nitrogen to the flare system. The flare delivery pipe 5 is normally closed. When the impurities carried by the circulating nitrogen are too much and cannot be collected by the buffer tank 4, the flare delivery pipe 5 is opened to ensure that the subsequent regeneration process can proceed normally.

[0029] The heating pipeline 7 and the cooling pipeline 10 are connected to the OCT feed processor 13 and the connection point is located at the top of the OCT feed processor 13. The OCT feed processor 13 is connected to the pipeline between the second cooler 2 and the C4 processor 1 through a pipeline. The OCT feed processor 13 is also used in the OCT process to adsorb the mixed raw materials (C4, C5 and ethylene) in the system to avoid catalyst poisoning. The OCT feed processor 13 also needs to be regenerated after adsorption. Therefore, the OCT feed processor 13 and the C4 processor 1 are configured to share a regeneration closed circulation system to reduce the use of equipment and reduce energy consumption. Figure 1 As shown, the tail ends of the heating pipeline 7 and the cooling pipeline 10 are both provided with valve groups, and the valve groups are provided with three valves. A flow regulating valve is provided between the two stop valves to control the nitrogen to enter the heating pipeline 7 or the cooling pipeline 10. The flow regulating valve can also adjust the output of the nitrogen.

[0030] The heater includes a steam heater 8 and an electric heater 9, and the steam heater 8 is located between the electric heater 9 and the blower 6. The steam heater 8 can be provided to utilize the high-temperature steam in the system for heating to reduce energy consumption, and the electric heater 9 is used to heat the nitrogen in one step to ensure that the nitrogen reaches the target temperature.

[0031] The regeneration closed circulation system of the present application has obvious energy-saving and consumption-reducing effects, and can greatly reduce nitrogen consumption. Since the regeneration process involves a heating process, the temperature of the circulating gas increases after entering the blower 6 and passing through the outlet of the blower 6 during the heating stage, which reduces the energy consumption of steam and electric heating. In the entire regeneration cycle, not only does the power consumption of the blower 6 not increase, but also the power of the electric heater 9 is reduced during the heating stage, which reduces the power consumption of the entire operation cycle. The energy-saving and consumption-reducing effect is obvious, and the production cost is reduced. The specific energy consumption comparison is shown in Table 1.

[0032] Table 1 Comparison of energy consumption before and after transformation

[0033]

[0034] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fixed bed adsorbent regeneration closed cycle system, comprising a C4 processor (1), characterized in that: The bottom of the C4 processor (1) is connected to a buffer tank (4) via a pipeline, the buffer tank (4) is connected to a blower (6) via a pipeline, the outlet of the blower (6) is connected to a heating pipeline (7) and a cooling pipeline (10), a heater is provided in the heating pipeline (7), a first cooler (11) is provided in the cooling pipeline (10), and the heating pipeline (7) and the cooling pipeline (10) are connected to a nitrogen circulation pipe (12) connected to the top of the C4 processor (1).

2. A fixed bed adsorbent regeneration closed circulation system according to claim 1, characterized in that: A second cooler (2) is provided between the C4 processor (1) and the buffer tank (4).

3. A fixed bed adsorbent regeneration closed circulation system according to claim 2, characterized in that: The pipeline connecting the second cooler (2) and the buffer tank (4) is connected to a nitrogen replenishing pipe (3).

4. A fixed bed adsorbent regeneration closed circulation system according to claim 2, characterized in that: The pipeline connecting the second cooler (2) and the buffer tank (4) is connected to a flare delivery pipe (5).

5. A fixed bed adsorbent regeneration closed circulation system according to claim 2, characterized in that: The heating pipeline (7) and the cooling pipeline (10) are connected to the OCT feed processor (13) and the connection point is located at the top of the OCT feed processor (13). The OCT feed processor (13) is connected to the pipeline between the second cooler (2) and the C4 processor (1) through the pipeline.

6. A fixed bed adsorbent regeneration closed circulation system according to claim 1, characterized in that: The heater comprises a steam heater (8) and an electric heater (9), wherein the steam heater (8) is located between the electric heater (9) and the blower (6).

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