N-butene isomerization system
By designing a multi-stage heat exchanger in the n-butene isomerization device, the efficient vaporization of raw material carbon 4 and the effective utilization of the latent heat of condensation is achieved, which solves the problem of high energy consumption of the device and reduces steam and electricity consumption.
Patent Information
- Application Number
- CN202520890396.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-08
- Publication Date
- 2025-06-10
- Estimated Expiration
- 2035-05-08
AI Technical Summary
In the existing n-butene isomerization device, the raw material carbon 4 vaporization requires a large amount of steam, resulting in high energy consumption; at the same time, the latent heat of gas phase condensation on the top of the de-heavy tower has not been effectively utilized, resulting in large air-cooling power consumption.
A n-butene isomerization system is designed to vaporize all the raw material carbon four through step-by-step heating by multi-stage heat exchangers (including the first, second and third heat exchangers), and heat exchange between the first heat exchanger and the gas phase on the top of the de-heavy tower is used to effectively utilize the latent heat of condensation.
The efficient vaporization of raw material carbon 4 and the effective utilization of condensation latent heat are realized, reducing the steam and electricity consumption of the device and reducing energy consumption.
Smart Images
Figure CN222956379U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of chemical reaction systems, in particular to a n-butene isomerization system. Background Art
[0002] The purpose of the n-butene isomerization unit is to isomerize n-butene in mixed C4 into isobutene, and then provide raw materials for the MTBE unit. The reaction temperature of this unit is 360 - 430 °C, and the reaction pressure is 0.05 - 0.1 MPaG, which is a gas-phase reaction. The raw material C4 feed is in liquid phase, and it needs to be completely vaporized by low-pressure steam before entering the subsequent reaction system. A large amount of steam is required for the vaporization of raw material C4. For example, a 300,000-ton / year n-butene isomerization unit requires 6 t / h of low-pressure steam for the vaporization of raw material C4, resulting in high energy consumption. At the same time, for the gas phase at the top of the heavy component separation tower in the subsequent product separation section, an air-cooling series water-cooling condensation and cooling method is adopted, and a large amount of latent heat of condensation of the gas phase is not effectively utilized, resulting in a large power consumption of the air-cooling and high energy consumption of the unit. Content of the Utility Model
[0003] The technical problem to be solved by the utility model is to overcome the defects of the prior art and provide a n-butene isomerization system, which has low investment, small floor area, is easy to implement on-site, can greatly reduce the steam and power consumption of the unit, and reduce the energy consumption of the unit.
[0004] In order to solve the above technical problems, the utility model provides the following technical solutions:
[0005] A n-butene isomerization system includes a raw material buffer tank. The raw material buffer tank is connected to an inlet and outlet heat exchanger through a pipeline. The inlet and outlet heat exchanger is connected to a heating furnace through a pipeline. The heating furnace is connected to a reactor through a pipeline. The output end of the reactor is connected to the inlet and outlet heat exchanger through a pipeline. After passing through the inlet and outlet heat exchanger, it is sequentially connected to a second heat exchanger and a reaction product cooler through a pipeline. The output end of the reaction product cooler is connected to a compressor. The compressor is connected to a heavy component separation tower. The top output end of the heavy component separation tower is connected to a first heat exchanger through a pipeline. After passing through the first heat exchanger, it is connected to a heavy component separation tower top condenser through a pipeline. The heavy component separation tower top condenser is connected to a heavy component separation tower reflux tank through a pipeline. The heavy component separation tower reflux tank is respectively connected to the top of the heavy component separation tower and an isomeric C4 pipeline through a pipeline;
[0006] A first heat exchange pipeline is connected to the pipeline between the raw material buffer tank and the inlet and outlet heat exchanger. The first heat exchange pipeline is connected to the first heat exchanger after flowing through the second heat exchanger, and is connected to the pipeline between the raw material buffer tank and the inlet and outlet heat exchanger again after flowing through the first heat exchanger.
[0007] In the above structure, the mixed C4 in the raw material buffer tank is gradually heated up through the second heat exchanger and the first heat exchanger in sequence and completely vaporized. A large amount of condensation latent heat of the gas phase at the top of the de-heavy tower is effectively utilized by heat exchange with the mixed C4 through the first heat exchanger, and the amount of cooling water used by the reaction product cooler is reduced.
[0008] Further, the bottom output end of the de-heavy tower is connected with a third heat exchanger through a pipeline. The first heat exchange pipeline flows through the third heat exchanger and is connected to the second heat exchanger after flowing through the third heat exchanger. The mixed C4 in the raw material buffer tank is gradually heated up through the third heat exchanger, the second heat exchanger, and the first heat exchanger in sequence and completely vaporized.
[0009] After flowing through the third heat exchanger, the bottom output end of the de-heavy tower is connected with a heavy component cooler through a pipeline.
[0010] A feed valve is connected to the pipeline between the raw material buffer tank and the inlet and outlet heat exchanger. The feed valve is arranged after the first heat exchange pipeline.
[0011] A raw material pump is connected to the pipeline between the raw material buffer tank and the inlet and outlet heat exchanger.
[0012] The first heat exchanger adopts a spiral wound tube heat exchanger, and the heat exchange tubes are made of thin-walled stainless steel.
[0013] The arrangement position of the first heat exchanger is higher than that of the condenser at the top of the de-heavy tower.
[0014] The beneficial effects achieved by the present utility model are as follows:
[0015] The present utility model has the characteristics of low investment and low floor area, solves the problems in the prior art such as large consumption of vapor for vaporizing raw material C4, ineffective utilization of a large amount of condensation latent heat of the gas phase at the top of the de-heavy tower, large power consumption of air cooling, and high energy consumption of the device, and has important significance for the energy-saving transformation of new or existing devices. Description of the Drawings
[0016] The drawings are used to provide further understanding of the present utility model, and constitute a part of the specification. Together with the embodiments of the present utility model, they are used to explain the present utility model, and do not constitute a limitation to the present utility model. In the drawings:
[0017] Figure 1 is a schematic structural diagram of the present utility model;
[0018] Figure 2 is a schematic structural diagram of the present utility model after the transformation of the existing device.
[0019] In the figure: 1. Raw material buffer tank; 2. Raw material pump; 3. Feed valve; 4. Feed and discharge heat exchanger; 5. Heating furnace; 6. Reactor; 7. Heavy component removal tower; 8. First heat exchanger; 9. Condenser at the top of the heavy component removal tower; 10. Reflux drum at the top of the heavy component removal tower; 11. Second heat exchanger; 12. Reaction product cooler; 13. Third heat exchanger; 14. Heavy component cooler; 15. Compressor; 16. First heat exchange pipeline; 17. Air cooler at the top of the heavy component removal tower; 18. Raw material vaporizer. Specific embodiments
[0020] The preferred embodiments of the present utility model will be described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present utility model, and are not used to limit the present utility model.
[0021] Embodiment 1:
[0022] As Figure 1 shown, a 1-butene isomerization system includes a raw material buffer tank 1. The raw material buffer tank 1 is connected to the feed and discharge heat exchanger 4 through a pipeline. The feed and discharge heat exchanger 4 is connected to the heating furnace 5 through a pipeline. The heating furnace 5 is connected to the reactor 6 through a pipeline. The output end of the reactor 6 is connected to the feed and discharge heat exchanger 4 through a pipeline. After passing through the feed and discharge heat exchanger 4, it is sequentially connected to the second heat exchanger 11 and the reaction product cooler 12 through a pipeline. The output end of the reaction product cooler 12 is connected to the compressor 15. The compressor 15 is connected to the heavy component removal tower 7. The top output end of the heavy component removal tower 7 is connected to the first heat exchanger 8 through a pipeline. After passing through the first heat exchanger 8, it is connected to the condenser at the top of the heavy component removal tower 9 through a pipeline. The condenser at the top of the heavy component removal tower 9 is connected to the reflux drum at the top of the heavy component removal tower 10 through a pipeline. The reflux drum at the top of the heavy component removal tower 10 is respectively connected to the top of the heavy component removal tower 7 and the isomeric C4 pipeline through pipelines.
[0023] The bottom output end of the heavy component removal tower 7 is connected with a third heat exchanger 13 through a pipeline.
[0024] A first heat exchange pipeline 16 is connected to the pipeline between the raw material buffer tank 1 and the feed and discharge heat exchanger 4. The first heat exchange pipeline 16 sequentially flows through the third heat exchanger 13, the second heat exchanger 11 and the first heat exchanger 8. After flowing through the first heat exchanger 8, it is connected again to the pipeline between the raw material buffer tank 1 and the feed and discharge heat exchanger 4, and feeds the feed and discharge heat exchanger 4.
[0025] After the bottom output end of the heavy component removal tower 7 flows through the third heat exchanger 13, it is connected with a heavy component cooler 14 through a pipeline.
[0026] A feed valve 3 is connected to the pipeline between the raw material buffer tank 1 and the feed and discharge heat exchanger 4. The feed valve 3 is arranged behind the first heat exchange pipeline 16.
[0027] A raw material pump 2 is connected to the pipeline between the raw material buffer tank 1 and the feed and discharge heat exchanger 4.
[0028] The first heat exchanger 8 adopts a wound tube heat exchanger, and the heat exchange tubes are made of thin-walled stainless steel. Compared with ordinary shell-and-tube heat exchangers, it can greatly improve the heat transfer efficiency, reduce the heat exchange area and the number of heat exchangers required, and reduce the floor area and investment.
[0029] The installation position of the first heat exchanger 8 is higher than that of the deweighting tower top condenser 9. The raw material C4 flows through the tube side, and the gas phase at the top of the deweighting tower 7 flows through the shell side. After the material in the shell side is condensed, it smoothly flows by gravity into the deweighting tower top condenser 9, which is beneficial to preventing gas blockage and ensuring the smooth flow of the condensed liquid phase. Moreover, this layout is easy to implement on site.
[0030] In the present utility model, the cold material, raw material C4, and the hot material, the gas phase at the top of the deweighting tower 7, exchange heat in the first heat exchanger 8. The raw material C4 is completely vaporized, and a large amount of latent heat of condensation of the gas phase at the top of the deweighting tower 7 is effectively utilized, which can greatly reduce the steam consumption and power consumption of the device. Moreover, the present utility model has low investment, few equipment, small floor area, and is easy to implement on site.
[0031] Embodiment 2:
[0032] As Figure 2 shown, based on an in-service device, it is transformed to obtain the system structure of the present utility model. Specifically, the structure and working process of the in-service device are as follows: The mixed C4 in the raw material buffer tank 1 is pressurized by the raw material pump 2 and enters the raw material vaporizer 18 to be completely vaporized. The vaporization heat source is 0.4 - 1.0 MPaG steam. The vaporized C4 is heated to the reaction temperature through heat exchange in the inlet and outlet heat exchanger 4 and further heated in the heating furnace 5, and then enters the reactor 6. The reaction product of the reactor 6 is cooled to 40°C through heat exchange in the inlet and outlet heat exchanger 4 and the reaction product cooler 12, and then enters the deweighting tower 7 after being pressurized to 0.6 - 0.7 MPaG by the compressor 15. The gas phase material at the top of the deweighting tower 7 is cooled to 40°C through the deweighting tower top air cooler 17 and the deweighting tower top condenser 9, and enters the deweighting tower reflux tank 10. Part of the isomeric C4 is refluxed to the top of the deweighting tower 7, and part of the isomeric C4 is sent to the product tank area as a product.
[0033] The transformation process is as follows: Three heat exchangers are added, including the first heat exchanger 8, the second heat exchanger 11, and the third heat exchanger 13, and the raw material vaporizer 18 and the deweighting tower top air cooler 17 are deactivated ( Figure 2 the dotted part in the figure), and a new cross line is set at this position. The mixed C4 is pressurized by the raw material pump 2, and the cold material is first preheated and temperature-raised through the newly added third heat exchanger 13 and the second heat exchanger 11 in sequence, and then enters the first heat exchanger 8. The gas phase at the top of the deweighting tower 7 enters the first heat exchanger 8 as the hot material. The cold and hot materials exchange heat in the first heat exchanger 8, the mixed C4 is completely vaporized, and the gas phase at the top of the deweighting tower 7 is partially condensed, and the latent heat of condensation of the gas phase is effectively utilized.
[0034] Specific application cases of the present utility model are as follows:
[0035] Table 1 Comparison of technical costs before and after transformation
[0036]
[0037] Taking the raw material catalytic C4 with a butene concentration of 45% and a 300,000-ton / year n-butene isomerization unit as an example. After the implementation of this technical solution, the inlet temperature of the cold material catalytic C4 in the 8 tube passes of the first heat exchanger is 40°C, the pressure is 0.3 MPaG, the vaporization fraction is 0, the outlet temperature is 43°C, the pressure is 0.27 MPaG, and the vaporization fraction is 100%. In this way, the raw material vaporizer 18 can be deactivated. The inlet temperature of the hot material in the 8 shell passes of the first heat exchanger is 55°C, the pressure is 0.52 MPaG, the vaporization fraction is 100%, the outlet temperature is 43°C, the pressure is 0.27 MPaG, and the vaporization fraction is 15%. In this way, the overhead air cooler 17 of the deweighting tower can be deactivated. It can save 6 t / h of 0.4 MPaG steam and 154 kW of the power consumption of the air cooler, greatly reducing the energy consumption of the unit.
Claims
1. A n-butene isomerization system, characterized in that: The invention comprises a raw material buffer tank (1), wherein the raw material buffer tank (1) is connected to an inlet and outlet heat exchanger (4) through a pipeline, the inlet and outlet heat exchanger (4) is connected to a heating furnace (5) through a pipeline, the heating furnace (5) is connected to a reactor (6) through a pipeline, the output end of the reactor (6) is connected to the inlet and outlet heat exchanger (4) through a pipeline, and after passing through the inlet and outlet heat exchanger (4), the output end is connected to a second heat exchanger (11) and a reaction product cooler (12) through pipelines in sequence, the output end of the reaction product cooler (12) is connected to a compressor (15), the compressor (15) is connected to a deweighting tower (7), the top output end of the deweighting tower (7) is connected to a first heat exchanger (8) through a pipeline, and after passing through the first heat exchanger (8), the top condenser (9) of the deweighting tower is connected to a deweighting tower reflux tank (10) through a pipeline, and the deweighting tower reflux tank (10) is respectively connected to the top of the deweighting tower (7) and an isomerized carbon four pipeline through pipelines; A first heat exchange pipe (16) is connected to the pipe between the raw material buffer tank (1) and the inlet and outlet heat exchanger (4); the first heat exchange pipe (16) flows through the second heat exchanger (11) and then is connected to the first heat exchanger (8); after flowing through the first heat exchanger (8), it is again connected to the pipe between the raw material buffer tank (1) and the inlet and outlet heat exchanger (4).
2. The n-butene isomerization system according to claim 1, characterized in that: The bottom output end of the deweighting tower (7) is connected to a third heat exchanger (13) via a pipeline, and the first heat exchange pipeline (16) flows through the third heat exchanger (13) and is connected to the second heat exchanger (11) after flowing through the third heat exchanger (13).
3. The n-butene isomerization system according to claim 2, characterized in that: The bottom output end of the deweighting tower (7) flows through the third heat exchanger (13) and is then connected to a heavy component cooler (14) via a pipeline.
4. The n-butene isomerization system according to claim 1, characterized in that: A feed valve (3) is connected to the pipeline between the raw material buffer tank (1) and the feed and discharge heat exchanger (4), and the feed valve (3) is arranged after the first heat exchange pipeline (16).
5. The n-butene isomerization system according to claim 1, characterized in that: A raw material pump (2) is connected to the pipeline between the raw material buffer tank (1) and the inlet and outlet heat exchanger (4).
6. The n-butene isomerization system according to claim 1, characterized in that: The first heat exchanger (8) is a wound tube heat exchanger, and the heat exchange tube is made of thin-walled stainless steel.
7. The n-butene isomerization system according to claim 1 or 6, characterized in that: The first heat exchanger (8) is arranged at a position higher than the deweighting tower top condenser (9).