An adipic acid reactor heat recovery system rich in hot water

Abstract

The present application relates to a kind of hot water-rich adipic acid reactor reaction heat recovery system, including adipic acid reactor, reactor cooling water tank, adipic acid water balance system and hot water recovery storage tank and delivery pump, multiple groups of reactor coil are provided in adipic acid reactor, WPH in coil becomes hot WPH, a part of hot WPH is cooled after directly entering hot water recovery storage tank by reactor cooling water tank, is sent to recrystallization process and salt-forming system pipeline by delivery pump and is cleaned and replaced;Adipic acid water balance system includes cold mother liquor tank, hot mother liquor tank, high-purity water storage tank, hot water storage tank, hot mother liquor heater, hot mother liquor pump and circulating pipeline.The present application is ingenious, by recovering hot water-rich adipic acid reactor, reduce the consumption of low-pressure steam for producing adipic acid, reduce production cost, the heat generated by reaction is recycled, to reach the purpose of reducing consumption, energy saving, for prior art, with good market prospect and development space.

Description

Technical Field

[0001] This invention relates to the field of adipic acid reactor reaction heat utilization, specifically to an adipic acid reactor reaction heat recovery system that produces abundant hot water. Background Technology

[0002] Among the existing adipic acid production processes, the nitric acid oxidation of KA oil is the most efficient and has the highest reaction yield. In the adipic acid production process, nitric acid acts as an oxidant and reacts with KA oil under the action of copper and vanadium catalysts to produce adipic acid. A large amount of heat is released during the reaction. The reactor has coils inside, through which WPH flows. Externally, there are circulating pumps and heat exchangers to remove the heat generated by the reaction. This heat is generally absorbed by cold water and then discharged, resulting in a serious waste of reaction heat resources and a significant increase in the cost of adipic acid.

[0003] In the adipic acid water balance system, when the liquid level in the hot mother liquor tank is insufficient, cold mother liquor is added. When the cold mother liquor is insufficient, WPH needs to be added to maintain the system balance and stability. In the water balance system, the cold mother liquor needs to be heated by low-pressure steam to become hot mother liquor. How to convert the externally added WPH into hot WPH without affecting the water balance has become the key point of the adipic acid production transformation.

[0004] Designing a reasonable, feasible, and ingenious method to recover the abundant hot water from the adipic acid reactor, thereby reducing the consumption of low-pressure steam for adipic acid production, lowering the cost of adipic acid production, and recovering and utilizing the heat generated in the reaction to achieve the goals of energy conservation and cost reduction, is a problem that needs to be solved. Summary of the Invention

[0005] To address the technical problems in existing adipic acid production processes, such as the large amount of heat released during the reaction, which is typically absorbed and then discharged using cold water heat exchangers, resulting in significant waste of reaction heat resources and increased costs, this invention provides a reaction heat recovery system for an adipic acid reactor rich in hot water. This system is rationally feasible and ingeniously designed. By recovering the abundant hot water from the adipic acid reactor, it reduces the consumption of low-pressure steam for adipic acid production, lowers production costs, and recovers and utilizes the heat generated during the reaction, thereby achieving energy conservation and cost reduction.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: an adipic acid reactor reaction heat recovery system for producing abundant hot water, including an adipic acid reactor, a reactor cooling water tank, an adipic acid water balance system, a hot water recovery storage tank, and a transfer pump. The adipic acid reactor is equipped with multiple sets of reactor coils. The WPH in the coils absorbs heat and becomes hot WPH. A portion of the hot WPH is cooled by the reactor cooling water tank and then directly enters the hot water recovery storage tank. It is then sent to the recrystallization process and salt formation system pipeline for cleaning and replacement by the transfer pump. The adipic acid water balance system includes a cold mother liquor tank, a hot mother liquor tank, a high-purity water storage tank, a hot soluble water storage tank, a hot mother liquor heater, a hot mother liquor pump, and a circulation pipeline.

[0007] The above is the basic embodiment of the present invention, and further improvements, refinements and limitations can be made on the basis of the above: For example, the adipic acid reactor is provided with a reactor cooling water pump and a first heat exchanger. In the reaction of nitric acid oxidizing KA oil in the adipic acid reactor, the heat generated is carried away by WPH in the reactor coil inside the adipic acid reactor. After heat exchange, part of the heat WPH is cooled by the external heat exchanger and then sent back to the reactor coil by the reactor cooling water pump for recycling.

[0008] The above is the basic implementation of the present invention, and further improvements, refinements and limitations can be made on the basis of the above: for example, circulating water WC is circulated in the first heat exchanger, and the circulating water WC exchanges heat with heat WPH in the first heat exchanger.

[0009] The above is the basic implementation of the present invention, and further improvements, refinements and limitations can be made on the basis of the above: such as the flow regulating valve and conductivity meter being provided on the pipeline connecting the reactor cooling water tank and the hot water recovery storage tank.

[0010] The above is the basic implementation of the present invention, and further improvements, refinements and limitations can be made on the basis of the above: As described, a transfer pump is provided outside the hot water recovery storage tank. The transfer pump sends a portion of the hot WPH to the adipic acid water balance system. A first liquid level control regulating valve and a second liquid level control regulating valve are respectively provided at the water inlet of the hot mother liquor tank and between the cold mother liquor tank and the hot mother liquor tank. When the cold mother liquor tank is replenished with water, under the "override control program", the cold mother liquor tank replenishes water to the hot mother liquor tank when the liquid level is in a safe state. The remainder is used to replenish hot WPH, and a portion is sent to the third recrystallization process and the cleaning and replacement of related pipelines of the salt formation system.

[0011] The above is the basic embodiment of the present invention, and further improvements, refinements and limitations can be made on the basis of the above: as described, a second heat exchanger and circulation pipeline are provided outside the hot water recovery storage tank, and the second heat exchanger is heated by steam condensate.

[0012] Compared with the prior art, the beneficial effects of the present invention are:

[0013] 1. The hot WPH that absorbs heat in the reactor coil is sent to the hot water recovery storage tank via the reactor cooling water tank, and then delivered to various users by a transfer pump to replace the hot WPH in the original system. This process recovers and reuses the hot water produced by the adipic acid reactor, reduces the consumption of low-pressure steam required for adipic acid production, and saves energy.

[0014] 2. The amount of heat that the second external heat exchanger of the adipic acid reactor needs to remove is also greatly reduced, thus reducing the consumption of circulating water WC.

[0015] 3. When heating WPH with low-pressure steam to generate hot WPH, if the amount used is small, the hot WPH will directly vaporize. If not operated properly, it may spray out and injure people. This eliminates the safety hazard here.

[0016] 4. The reactor cooling water tank and the hot water recovery storage tank are equipped with a conductivity meter and a regulating valve. The conductivity meter can detect whether the internal coils of the reactor are leaking online, providing a basis for judgment. The regulating valve ensures the stability of the liquid level in the hot water recovery storage tank. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] In the diagram: 1. Adipic acid reactor, 2. Reactor cooling water tank, 3. First heat exchanger, 4. Second heat exchanger, 5. Hot water recovery storage tank, 6. Transfer pump, 7. Cold mother liquor tank, 8. Hot mother liquor tank, 9. Reactor coil, 10. First liquid level control valve, 11. Second liquid level control valve, 12. Conductivity meter, 13. Flow control valve. Detailed Implementation

[0019] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0020] A reaction heat recovery system for an adipic acid reactor rich in hot water includes an adipic acid reactor 1, a reactor cooling water tank 2, an adipic acid water balance system, a hot water recovery storage tank 5, and a transfer pump 6. The adipic acid reactor 1 is equipped with multiple sets of reactor coils 9. The WPH in the coils absorbs heat and becomes hot WPH. A portion of the hot WPH is cooled by the reactor cooling water tank 2 and then directly enters the hot water recovery storage tank 5. It is then sent to the recrystallization process and salt formation system pipelines for cleaning and replacement by the transfer pump 6. The adipic acid water balance system includes a cold mother liquor tank 7, a hot mother liquor tank 8, a high-purity water storage tank, a hot soluble water storage tank, a hot mother liquor heater, a hot mother liquor pump, and circulation pipelines.

[0021] The adipic acid reactor 1 is externally equipped with a reactor cooling water pump and a first heat exchanger 3. During the reaction of nitric acid oxidizing KA oil in the adipic acid reactor 1, the heat generated is carried away by WPH in the reactor coil 9 inside the adipic acid reactor 1. After heat exchange, part of the heat WPH is cooled by the external heat exchanger and then sent back to the reactor coil 9 by the reactor cooling water pump for recycling.

[0022] The first heat exchanger 3 is filled with circulating water WC, which exchanges heat with heat WPH within the first heat exchanger 3.

[0023] The reactor cooling water tank 2 and the hot water recovery storage tank 5 are connected by a flow regulating valve 13 and a conductivity meter 12.

[0024] The hot water recovery storage tank 5 is equipped with a transfer pump 6, which sends a portion of the hot WPH to the adipic acid water balance system. The inlet of the hot mother liquor tank 8 and the middle of the cold mother liquor tank 7 and the hot mother liquor tank 8 are respectively equipped with a first liquid level control regulating valve 10 and a second liquid level control regulating valve 11. When the cold mother liquor tank 7 is replenished with water, under the "override control program", the cold mother liquor tank 7 replenishes water to the hot mother liquor tank 8 when the liquid level is in a safe state. The remainder is used to replenish hot WPH, and a portion is sent to the third recrystallization process and the cleaning and replacement of related pipelines in the salt formation system.

[0025] The hot water recovery storage tank 5 is equipped with a second heat exchanger 4 and a circulation pipeline on the outside. The second heat exchanger 4 is heated by steam condensate.

[0026] In actual operation, the working process of the adipic acid reactor reaction heat recovery system of the present invention is as follows: Figure 1 As shown, in the adipic acid reactor 1, the oxidation of KA oil by nitric acid releases a large amount of heat. Within the adipic acid reactor coil 9, WPH absorbs heat and becomes 80°C hot WPH, which then enters the reactor cooling water tank 2 through the coil outlet. Part of the hot WPH is cooled by the circulating water WC in the first heat exchanger 3 and then pumped back into the coil by the cooling water pump for reuse. The other part of the 80°C hot WPH is sent from the reactor cooling water tank 2 to the hot water recovery storage tank 5. The WPH sent to the hot water recovery storage tank 5 is replenished by the WPH makeup water valve at the reactor cooling water pump inlet, ensuring the stability of the reactor cooling water pump circulation.

[0027] The hot water recovery storage tank 5 contains heat WPH, which is sent to the second heat exchanger 4 via the transfer pump 6. The second heat exchanger 4 is externally connected to a CCL at about 83°C. The outlet of the second heat exchanger 4 is equipped with a circulation pipeline. This ensures the stability of the hot water recovery storage tank 5 and prevents the transfer pump 6 from being pressurized.

[0028] A portion of the heat WPH from the outlet of the second heat exchanger 4 is sent to the hot mother liquor tank 8 in the adipic acid water balance system. Here, controlled by the "override control program," when replenishing water to the hot mother liquor tank 8, the hot WPH in the hot water recovery storage tank 5 is used first for replenishment, while ensuring the safe liquid level of the cold mother liquor tank 7, and then the cold mother liquor tank 7 is used. The heat WPH used here is about 4 T / H, saving about 0.610 T / H of low-pressure steam.

[0029] In the adipic acid production process, the heat WPH required for cleaning and purging of the third recrystallization step and related pipelines in the salt formation system is obtained through heat exchange between WPH and low-pressure steam, with approximately 3 T / H of WPH used. This portion of the WPH requiring low-pressure steam heat exchange is replaced by the heat WPH in the hot water recovery storage tank 5, thereby reducing the consumption of low-pressure steam. This saves approximately 0.455 T / H of low-pressure steam.

[0030] In summary, this hot water recovery system achieves the recovery and utilization of reactor reaction heat, avoiding heat loss caused by the reactor reaction heat being carried away by the circulating water WC. At the same time, it reduces the consumption of circulating water WC and low-pressure steam, with low-pressure steam consumption reduced by approximately 1.1 T / H, thus saving production costs.

[0031] The method of this invention is reasonable, feasible, and ingeniously designed. By recovering the abundant hot water produced in the adipic acid reactor, it reduces the consumption of low-pressure steam for adipic acid production, thereby lowering the cost of adipic acid production. It also recovers and utilizes the heat generated in the reaction to achieve the goals of reducing consumption and saving energy. This invention solves the technical problems in existing adipic acid production processes, such as the large amount of heat released during the reaction, which is generally treated by absorbing the heat through cold water and then discharging it, resulting in a serious waste of reaction heat resources and a significant increase in the cost of adipic acid. Compared with existing technologies, this invention has a very good market prospect and development space.

[0032] The preferred embodiments and examples of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments and examples. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the concept of the present invention.

Claims

1. A heat recovery system for an adipic acid reactor rich in hot water, characterized in that: The system includes an adipic acid reactor (1), a reactor cooling water tank (2), an adipic acid water balance system, a hot water recovery storage tank (5), and a transfer pump (6). The adipic acid reactor (1) is equipped with multiple reactor coils (9). The WPH in the coil absorbs heat and becomes hot WPH. A portion of the hot WPH is cooled by the reactor cooling water tank (2) and then directly enters the hot water recovery storage tank (5). It is then sent to the recrystallization process and salt formation system pipelines for cleaning and replacement via the transfer pump (6). The adipic acid water balance system includes a cold mother liquor tank (7), a hot mother liquor tank (8), a high-purity water storage tank, a hot soluble water storage tank, a hot mother liquor heater, a hot mother liquor pump, and a circulation pipeline. The hot water recovery storage tank (5) is equipped with a transfer pump (6) on the outside. The transfer pump (6) sends a portion of the hot WPH to the adipic acid water balance system. The inlet of the hot mother liquor tank (8) and the middle of the cold mother liquor tank (7) and the hot mother liquor tank (8) are respectively equipped with a first liquid level control regulating valve (10) and a second liquid level control regulating valve (11). When the cold mother liquor tank (7) is replenished with water, under the "override control program", the cold mother liquor tank (7) replenishes water to the hot mother liquor tank (8) when the liquid level is in a safe state. The rest is used to replenish hot WPH, and a portion is sent to the third recrystallization process and the cleaning and replacement of related pipelines of the salt formation system.

2. The adipic acid reactor reaction heat recovery system with abundant hot water production according to claim 1, characterized in that: The adipic acid reactor (1) is equipped with a reactor cooling water pump and a first heat exchanger (3) on the outside. During the reaction of nitric acid oxidizing KA oil in the adipic acid reactor (1), the heat generated is carried away by WPH in the reactor coil (9) inside the adipic acid reactor (1). After the heat exchange, part of the heat WPH is cooled by the external heat exchanger and then sent back to the reactor coil (9) for recycling by the reactor cooling water pump.

3. The adipic acid reactor reaction heat recovery system with abundant hot water production according to claim 2, characterized in that: The first heat exchanger (3) is filled with circulating water WC, which exchanges heat with heat WPH in the first heat exchanger (3).

4. The adipic acid reactor reaction heat recovery system with abundant hot water production according to claim 1, characterized in that: The reactor cooling water tank (2) and the hot water recovery storage tank (5) are connected by a flow regulating valve (13) and a conductivity meter (12).

5. The adipic acid reactor reaction heat recovery system with abundant hot water production according to claim 1, characterized in that: The hot water recovery storage tank (5) is equipped with a second heat exchanger (4) and a circulation pipeline on the outside. The second heat exchanger (4) is heated by steam condensate.

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