System and process for producing phthalic acid by strengthening xylene oxidation

A technology for producing phthalic acid and xylene, which is applied in the field of preparation of phthalic acid, can solve the problems of increasing reaction cost, increasing the risk of reaction device, and high reaction pressure, so as to achieve improved utilization rate, long residence time, and reduced reaction the effect of time

Pending Publication Date: 2021-03-26
NANJING YANCHANG REACTION TECH RES INST CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In the prior art, the reaction pressure in the preparation process of phthalic acid is relatively high, which increases the danger of the reaction device. At the same time, the excessive reaction pressure will cause more energy loss and further increase the reaction cost.

Method used

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  • System and process for producing phthalic acid by strengthening xylene oxidation

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Experimental program
Comparison scheme
Effect test

Embodiment 1

[0043] The use of o-xylene with a purity of 98% is the oxidation of phthalic acid as a raw material. When starting the reaction, valve 14 and valve 15 were in a closed state earlier, and the acetic acid solvent and o-xylene entered the slurry bed reactor to form a mixed solution. Oxygen enters the second micro-interface generator and is broken into micron-sized bubbles, forming a gas-liquid emulsion with the surrounding mixed solution; at the same time, the catalyst enters the slurry bed reaction from the catalyst dosing pipeline above the second micro-interface generator device, and is suspended in the slurry bed reactor by the action of the micron-sized bubbles broken up by the second micro-interface generator floating upward; after 47 minutes of reaction, the valve 14 and the valve 15 are opened, and the temperature control circulation unit starts to work, and the The liquid phase material at the bottom of the slurry bed reactor is drawn out, and after being cooled by the he...

Embodiment 2

[0046] Using m-xylene with a purity of 99.5% as raw material to oxidize isophthalic acid, the reaction pressure is 1.5MPa, the weight ratio of solvent to m-xylene in the slurry bed reactor is 4:1, when the reaction starts, the valve 14 And the valve 15 is in the closed state first, the acetic acid solvent and m-xylene enter the slurry bed reactor to form a mixed solution, and the oxygen enters the second micro-interface generator and is broken into micron-scale bubbles, forming a gas mixture with the surrounding mixed solution. liquid emulsion; at the same time, the catalyst enters the slurry bed reactor from the catalyst dosing pipeline above the second micro-interface generator, and is suspended in the slurry state by the micron-sized bubbles broken by the second micro-interface generator. In the bed reactor; after 47 minutes of reaction, the valve 14 and the valve 15 are opened, and the temperature control circulation unit starts to work, which extracts the liquid phase mate...

Embodiment 3

[0049] Using p-xylene as raw material to oxidize terephthalic acid, the reaction pressure is 1.45MPa, and the mass ratio of p-xylene, acetic acid solvent and catalyst is 1:3:0.001; when starting the reaction, acetic acid solvent and p-xylene enter A mixed solution is formed in the slurry bed reactor, oxygen enters the second micro-interface generator and is broken into micron-sized bubbles, forming a gas-liquid emulsion with the surrounding mixed solution; at the same time, the catalyst is released from above the second micro-interface generator The catalyst dosing pipeline enters the slurry bed reactor, and is suspended in the slurry bed reactor by the action of the micron-sized bubbles broken by the second micro-interface generator floating upward; the temperature control circulation unit The liquid phase material at the bottom is drawn out, and after being heated or cooled to 150°C by a heat exchanger, it is sent together with the liquid phase material separated from the sep...

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Abstract

The invention provides a system and process for producing phthalic acid by strengthening xylene oxidation. The system comprises a slurry bed reactor, micro-interface generators, a circulating pipeline, a gas inlet pipeline and a separation unit, wherein the upper part of the slurry bed reactor is communicated with the condensation unit, and the lower part is communicated with the crystallization filter; the micro-interface generators are arranged in the slurry bed reactor and used for crushing gas into micron-sized micro bubbles, so that the mass transfer efficiency of gas and liquid is improved, and the reaction pressure is reduced; the circulating pipeline is used for pumping a liquid-phase material at the bottom of the slurry bed reactor into the second micro-interface generator; and afeed port of the separation unit is connected with the condensation unit, and a liquid-phase material outlet of the separation unit is communicated with a liquid-phase material inlet of the first micro-interface generator.

Description

technical field [0001] The invention relates to the preparation of phthalic acid, in particular to a system and process for strengthening the oxidation of xylene to produce phthalic acid. Background technique [0002] Xylene is a colorless and transparent liquid; it is a product in which two hydrogens on the benzene ring are replaced by methyl groups, and there are three isomers of ortho, meta, and p. In industry, xylene refers to the mixture of the above isomers; its Oxygen oxidation can produce phthalic acid, terephthalic acid, isophthalic acid and other substances respectively. [0003] Phthalic acid is a colorless crystal or crystalline powder. It is a binary aromatic carboxyl formed by connecting two carboxyl groups to two adjacent carbon atoms in the benzene ring. In applications, phthalic anhydride can be used instead of phthalic acid. Diformic acid. Phthalic acid is a raw material for synthetic resins, fibers, and pharmaceuticals. Isophthalic acid (IPA for short) ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B01J8/22B01J8/08B01J8/00B01J19/00C07C51/265C07C63/26
CPCB01J8/22B01J8/082B01J8/001B01J19/0093C07C51/265B01J2208/00017C07C63/26B01J8/00B01J8/08B01J19/00B01J19/24C07C63/24
Inventor 张志炳周政李磊张锋孟为民王宝荣杨高东罗华勋杨国强田洪舟
Owner NANJING YANCHANG REACTION TECH RES INST CO LTD
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