Recovery process of PX oxidation residues and recovery system device thereof

Abstract

The invention discloses a recovery process of PX (p-xylene) oxidation residues, and the process comprises primary treatment, secondary esterification, fine distillation, ion exchange, and subsequent treatment of wastewater, exhaust gas and waste residues. The invention also discloses a recovery system device used for the recovery process of PX oxidation residues. The device consists of a high temperature flash dryer, a pulverizer, a reaction dissolving kettle, a first esterification instrument, a second esterification instrument, series of rectification towers, an ion exchange instrument, a wastewater treatment instrument and a tail gas absorption tower that are connected in order, and also includes a methanol recovery system. The process of the invention can extract various material components in large amounts and high purity, has low requirement for production equipment and basically no corrosion, and realizes recycling of wastes, which can achieve resource utilization to the utmost and a highest utilization rate. Meanwhile, the process in the invention solves the environmental protection pressure of enterprises, basically realizes no three wastes, thus being consistent with the green environmental protection concept of low carbon and having competitive edges.

Description

technical field [0001] The invention relates to a recovery process of PX oxidation residue, and also relates to a recovery system device used in the recovery process of PX oxidation residue. Background technique [0002] Since the reform and opening up, my country's petrochemical industry has achieved unprecedented development, p-xylene is almost all used to produce PTA, in the production process, there are a large number of side reactions, and there are residues, namely PX oxidation residues, complex components, Contains a large amount of benzoic acid, terephthalic acid, isophthalic acid, p-toluic acid, cobalt, manganese and other organic components; however, due to the complex and unstable composition, the recovery cost is high, and people generally use the following methods : [0003] One is to directly bury the residue. Although it is simple, it will cause great and immeasurable risks to the environment and seriously pollute the surrounding environment; [0004] Second, ...

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Problems solved by technology

[0003] One is to directly bury the residue. Although it is simple, it will cause great and immeasurable risks to the environment and seriously pollute the surrounding environment;

[0004] Second, it is direct incineration, which will generate a large amount of carbon dioxide, which will aggravate the greenhouse effect, and does not meet the current national low-carbon environmental protection requirements;

[0005] 3. Alkali treatment will generate a large amount of sludge, which is also treated by landfill, which will also cause environmental pollution and does not meet the national environmental requirements;

[0008] 1. There are not many components for extracting useful substances. In general, only benzoic acid is extracted, and other components are generally not extracted, resulting in waste of resources;

[0009] 2. The extraction of acid substances generally requires equipment and has a corrosive effect, which will increase production costs and cause certain pressure on environmental protection;

[0010] 3. In some processes, the esterification reaction efficiency of acid substances is not high, so it is necessary to add methyl ester for multiple esterification reactions in the recrystallization to improve the esterification rate; however, recrystallization will cause equipment Blockage, affecting the improvement of production efficiency;

[0011] 4. Due to the low efficiency of esterification, the terephthalic acid, isophthalic acid and benzoic acid that have not been esterified will have a certain impact on equipment, the environment and the staff, so it is not a long-term solution. Conform to the concept of low carbon, environmental protection and green advocated by the country, as well as the scientific concept of development;

[0012] 5. The resulting product is a mixed ester. For this reason, if the individual components are needed in the follow-up, further separation is required, which will increase the process, and then involve the configuration of production equipment, manual configuration and site requirements, resulting in increased production costs. Conducive to the sustainable competition of enterprises in the market;

[0013] 6. Due to insufficient or most of the components in the oxidation residue are extracted, the remaining substances after extraction will continue to affect and pollute the environment, which is not conducive to long-term development;

[0014] 7. In order to obtain high-purity products, the existing production process is complicated;

[0015] 8. The waste gas, waste residue and waste water generated in the existing process have not been well treated, which has affected the surrounding environment and restricted the development of the enterprise

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