System for improving load of air compressor of PTA (pure terephthalic acid) main device

Abstract

The utility model discloses a system for improving the load of an air compressor of a PTA (pure terephthalic acid) main device, which belongs to the field of terephthalic acid production equipment and is characterized in that an oxidation reactor, a primary rectifying tower, a secondary rectifying tower, an oxidation reactor condenser, a high-pressure absorption tower, a tail gas incineration reactor and a tail gas washing tower are communicated through pipelines; the tail gas incineration reactor, the tail gas expansion machine and the tail gas emptying washing tower are communicated through pipelines, the air inlet filter, the oxygen concentration tower, the air compressor and the oxidation reactor are communicated through pipelines, and the steam turbine, the air compressor and the tail gas expansion machine are communicated through pipelines. The device solves the technical problem that the expansion of the whole production scale is limited because the load of the device in the prior art cannot be changed once being determined, and is mainly applied to terephthalic acid production.

Description

TECHNICAL FIELD

[0001] The utility model belongs to terephthalic acid production technical field, more particularly in a kind of PTA main device air compressor load system of promotion. BACKGROUND

[0002] At present, PTA is mainly obtained by the following production method: under specific temperature and pressure conditions, using cobalt, manganese, bromine catalyst, air and p-xylene are reacted to generate terephthalic acid. Among them, the air required for reaction is provided by the air compressor in the compressor set. The heat generated during the reaction is transmitted to the rectifying column, steam drum and cooler by means of the reaction tail gas. The reaction tail gas needs to go through rectification, cooling and washing processes, and then a part is incinerated, a small part is used in the device after drying, and most of them enter the tail gas expander of the compressor set to realize energy recovery, and finally are vented after washing.

[0003] The design load of the prior art device is determined once, and the design capacity of the air compressor becomes the key bottleneck restricting the load of the PTA device. Because the design capacity of the air compressor is planned according to the established device load, if the device load is to be increased, the air compressor may not be able to provide sufficient air volume, thereby limiting the expansion of the entire production scale. Therefore, a new production system is proposed. SUMMARY

[0004] To achieve the above purpose, the utility model provides a kind of PTA main device air compressor load system of promotion, solve the technical problem that the load of prior art device is determined once and cannot be changed, thereby limiting the expansion of the entire production scale.

[0005] To achieve the above purpose, the utility model provides a kind of PTA main device air compressor load system of promotion,

[0006] A kind of PTA main device air compressor load system of promotion, including oxidation reactor, primary rectifying column, secondary rectifying column, oxidation reactor condenser, high pressure absorption tower, tail gas incineration reactor, tail gas washing tower, tail gas expander, air compressor, steam turbine, air inlet filter, oxygen concentration tower and tail gas venting washing tower, it is characterized by: oxidation reactor, primary rectifying column, secondary rectifying column, oxidation reactor condenser, high pressure absorption tower, tail gas incineration reactor and tail gas washing tower are communicated by pipeline;

[0007] Tail gas incineration reactor, tail gas expander and tail gas venting washing tower are communicated by pipeline;

[0008] Air inlet filter, oxygen concentration tower, air compressor and oxidation reactor are communicated by pipeline;

[0009] The steam turbine, air compressor and tail gas expander are connected through pipelines.

[0010] Compared with the prior art, the technical effects and advantages of the present application are:

[0011] The oxygen content in the oxygen-enriched air is controlled to be 22-30%, the prepared oxygen-enriched air is added into the oxidation reactor to react with the para-xylene, and the upper limit of the device load can be effectively improved. Compared with the prior art, the tail gas emission amount is reduced, the energy consumption and investment cost are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1 The present application is a system diagram.

[0013] In the figure, 1 is an oxidation reactor, 2 is a first-stage rectifying tower, 3 is a second-stage rectifying tower, 4 is an oxidation reactor condenser, 5 is a high-pressure absorption tower, 6 is a tail gas incineration reactor, 7 is a tail gas washing tower, 8 is a tail gas expander, 9 is an air compressor, 10 is a steam turbine, 11 is an air inlet filter, 12 is an oxygen concentration tower, and 13 is a tail gas vent washing tower. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0015] EMBODIMENT

[0016] Please refer to Figure 1 A system for improving the load of an air compressor of a PTA main device, comprising an oxidation reactor 1, a first-stage rectifying tower 2, a second-stage rectifying tower 3, an oxidation reactor condenser 4, a high-pressure absorption tower 5, a tail gas incineration reactor 6, a tail gas washing tower 7, a tail gas expander 8, an air compressor 9, a steam turbine 10, an air inlet filter 11, an oxygen concentration tower 12 and a tail gas vent washing tower 13, characterized in that the oxidation reactor 1, the first-stage rectifying tower 2, the second-stage rectifying tower 3, the oxidation reactor condenser 4, the high-pressure absorption tower 5, the tail gas incineration reactor 6 and the tail gas washing tower 7 are connected through pipelines;

[0017] The tail gas incineration reactor 6, the tail gas expander 8 and the tail gas vent washing tower 13 are connected through pipelines;

[0018] The air inlet filter 11, the oxygen concentration tower 12, the air compressor 9 and the oxidation reactor 1 are connected through pipelines;

[0019] The steam turbine 10, the air compressor 9 and the tail gas expander 8 are connected by pipelines.

[0020] After the air passes through the air filter 11, it is purified by the oxygen concentration tower 12, so that the oxygen content of the air compressed by the air compressor 9 is increased from 20.9% to 22%-30%. The purified air compressed by the air compressor 9 enters the oxidation reactor 1 to react with the feed PX of the oxidation reactor 1 to generate CTA, and the CTA is sent to a refining treatment to obtain PTA. Since the oxygen content in the air is increased, the load of PX can also be increased, so that the load of the device is not limited by the load of the air compressor 9, the yield is increased, and the cost is reduced. After the purified air at the outlet of the air compressor 9 consumes most of the oxygen in the oxidation reactor 1, the remaining tail gas and the acetic acid and water vapor evaporated from the oxidation reactor 1 enter the primary rectifying tower 2, and then enter the secondary rectifying tower 3. The secondary rectifying tower 3 separates acetic acid and water, and the acetic acid returns to the oxidation reactor 1. The remaining tail gas and water vapor enter the tail gas condenser 4 to condense the water vapor, and the remaining tail gas enters the high-pressure absorption tower 5 to spray wash and purify the tail gas. The purified tail gas is further treated in the tail gas incineration reactor 6 to further eliminate organic matter. The burned organic matter further increases the temperature of the tail gas. A small part of the tail gas at the outlet of the tail gas incineration reactor 6 enters the tail gas washing tower 7 for further washing and drying to provide tail gas for sealing and air supply for the entire device. Most of the tail gas enters the tail gas expander 8 to recover energy for power generation to generate benefits. The tail gas at the outlet of the tail gas expander 8 enters the tail gas venting washing tower 13 for spray washing, and is vented to the atmosphere after meeting the environmental protection requirements. Since the air is purified, the tail gas content is reduced compared to before purification, thereby reducing the tail gas emission, making the plant more environmentally friendly. The external tail gas condenser produces steam, which enters the steam turbine 10 to do work, providing power for the air compressor 9. The excess energy will be used for power generation to generate benefits for the plant. Since the air is purified, the PX load of the device can be increased, thereby generating more heat to make the plant generate more power and generate more benefits.

[0021] Since the oxygen content at the outlet of the air compressor 9 is increased, the oxidation of PX in the oxidation reactor 1 is beneficial to proceed in the positive direction, thereby reducing the use amount of catalyst of the device, reducing the cost, reducing the emission, and reducing the sewage treatment cost, so that the benefits of the device are further improved.

Claims

1. A system for lifting the load of air compressor of PTA main plant comprising oxidation reactor (1), first rectifying column (2), second rectifying column (3), oxidation reactor condenser (4), high pressure absorption column (5), tail gas incineration reactor (6), tail gas washing column (7), tail gas expander (8), air compressor (9), steam turbine (10), air inlet filter (11), oxygen concentration column (12) and tail gas vent washing column (13), characterized in that: The oxidation reactor (1), the primary rectifying tower (2), the secondary rectifying tower (3), the oxidation reactor condenser (4), the high-pressure absorption tower (5), the tail gas incineration reactor (6) and the tail gas washing tower (7) are communicated by pipes; The tail gas incineration reactor (6), the tail gas expander (8) and the tail gas venting washing tower (13) are communicated by pipes; The air inlet filter (11), the oxygen concentration tower (12), the air compressor (9) and the oxidation reactor (1) are communicated by pipes; The steam turbine (10), the air compressor (9) and the tail gas expander (8) are communicated by pipes.

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