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Method for purifying crude isophthalic acid oxidation slurry

A technology for crude isophthalic acid and oxidation slurry, which is applied in the field of purification of crude isophthalic acid oxidation slurry, and can solve the problems of increasing the acetic acid-water solution process and its energy consumption

Active Publication Date: 2015-08-12
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Although the treatment method of the crude terephthalic acid oxidation slurry proposed in the above-mentioned documents can save the drying unit, it will inevitably produce acetic acid-water solution, which will increase the subsequent processing of acetic acid-water solution and its energy consumption

Method used

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  • Method for purifying crude isophthalic acid oxidation slurry
  • Method for purifying crude isophthalic acid oxidation slurry
  • Method for purifying crude isophthalic acid oxidation slurry

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0034] Such as figure 1 and 2 As shown, take 2000 grams of oxidation reactor 1 and obtain the crude isophthalic acid oxidation slurry-flash slurry I6 obtained by three-stage decompression flash evaporation, wherein the temperature of the first stage decompression flash evaporation is 201 ° C, and the flash The steaming pressure is 11.62kg / cm 2 , the temperature of the second-stage decompression flash is 159°C, and the pressure of the flash is 4.59kg / cm 2 , the temperature of the third-stage decompression flash is 92°C, and the pressure of the flash is 0.50kg / cm 2 , the flash slurry I6 enters into a pressure difference of 2.5kg / cm through the slurry pump 5 under the following physical property conditions 2 The first stage 23 of the rotary drum filter press 10 of the rotary drum filter press performs pressure filtration: the space velocity is 22hr -1 , by weight percentage, isophthalic acid 26.79%, catalyst 0.21%, acetic acid concentration 64.50%, other impurities 8.50%, tem...

Embodiment 2～3

[0036] Such as image 3 , 4 As shown in 5 and 6, only the first oxygen-containing flow-air purge times and the second oxygen-containing flow-air purge stages in Example 1 are changed. The results are shown in Table 1.

Embodiment 4

[0038] Only the purging step of the oxygen-containing stream in Example 1 was removed, and the others were correspondingly kept unchanged. The results are shown in Table 1. It can be seen from the data in Table 1 that if the oxygen-containing flow purging step is omitted, the filter cake VIII12 will still have a large amount of m-xylene in addition to the high residual amount of acetic acid, requiring other complicated post-treatment procedures.

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Abstract

The invention relates to a method for purifying crude isophthalic acid oxidized sizing agent, which is mainly used for solving a water-ethanol solution generating problem in the prior art. The method comprises the following steps of: carrying out reduced pressure flash evaporation on the crude isophthalic acid oxidized sizing agent which is obtained by an oxidation reactor to obtain flash evaporation sizing agent I and flash evaporation liquid II; filtering the flash evaporation sizing agent I to obtain a filter cake III and filtrate IV; blowing the inner part of the filter cake III by oxygen-containing gas flow; removing residual impurities in the filter cake III to obtain the filter cake V by virtue of a gas flow entrainment way and blowing tail gas A; washing the filter cake V by m-xylene or acetic ester to obtain the filter cake VI and the filtrate VII; blowing the inner part of the filter cake VI by the oxygen-containing gas flow, and filtering the residual impurities in the filter cake VI to obtain the filter cake VIII by virtue of the gas flow entrainment way, and blowing the tail gas B. According to the technical scheme, the water-ethanol solution generating problem is solved well, so the method can be applied to the industrial production for purifying the crude isophthalic acid oxidized sizing agent.

Description

technical field [0001] The invention relates to a method for purifying crude isophthalic acid oxidation slurry. Background technique [0002] Aromatic carboxylic acid is a very important chemical raw material, and there is a huge market demand. Although the domestic isophthalic acid (PIA) industry has developed rapidly in recent years, the production capacity has increased year by year, and the demand has also continued to increase. The mainstream production process of PIA-the production process of refined PIA generally includes two stages of oxidation and refining. Toluene is oxidized in high temperature liquid phase to obtain crude isophthalic acid oxidation slurry with acetic acid as solvent, while pure water is used as solvent in the refining process, so it is necessary to replace the acetic acid solvent in the oxidation slurry obtained in the oxidation process with water solvent, and at the same time Reduce the content of impurities such as acetic acid and catalyst, a...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C07C63/24C07C51/42
Inventor 张海涛畅延青
Owner CHINA PETROLEUM & CHEM CORP