Method for continuously producing high-purity o-chlorotoluene by adsorption separation method

A high-purity o-chlorotoluene technology, applied in the field of continuous production of high-purity o-chlorotoluene by adsorption separation, can solve the problems of inability to obtain high-purity o-chlorotoluene, avoid recovery steps, reduce processing costs, and simplify the process. line effect

Pending Publication Date: 2022-08-09
NANJING UNIV OF TECH +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

The boiling point difference between o-chlorotoluene and p-chlorotoluene is only about 3°C,

Method used

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  • Method for continuously producing high-purity o-chlorotoluene by adsorption separation method
  • Method for continuously producing high-purity o-chlorotoluene by adsorption separation method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0031] Take 50 g of o-chlorotoluene solutions of different production batches, add different types of molecular sieve adsorbents, stir at room temperature for a certain period of time, filter, analyze the mass fraction of o-chlorotoluene in the filtrate, and compare the adsorption effects of different adsorbents. The results are shown in Table 1. Show. It shows that the above molecular sieve adsorbents can selectively adsorb p-chlorotoluene in the o-chlorotoluene solution to obtain o-chlorotoluene with a mass fraction of ≥99.95%.

[0032] Table 1. Adsorption effects of different molecular sieve adsorbents

[0033]

Embodiment 2

[0035] like figure 1As shown, a system for continuous production of high-purity o-chlorotoluene by an adsorption separation method includes a first tubular adsorption tower 4 and a second tubular adsorption tower 5 connected in parallel, an o-chlorotoluene raw material storage tank 7, an adjacent Chlorotoluene product tank 8, toluene storage tank 6, condenser 9; the pipe-side inlets of the first row of tubular adsorption towers 4 are respectively connected with the o-chlorotoluene raw material storage tank 7 through the first ortho-chlorotoluene feed pipeline, and are connected through the first ortho-chlorotoluene feed pipeline respectively. A desorbent feed line is connected to the toluene storage tank 6, the first desorber feed line is connected to the blower 3 for feeding nitrogen into the tube path of the first tubular adsorption tower 4, the first The tube-side outlets of a row of tubular adsorption towers 4 are respectively connected to the o-chlorotoluene product tank ...

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Abstract

The invention discloses a method for producing high-purity o-chlorotoluene, which comprises the following steps: filling a molecular sieve adsorbent in a tube pass of a tubular adsorption tower, introducing circulating cooling water into a shell pass of the tubular adsorption tower, and introducing an o-chlorotoluene raw material to be purified into the tube pass to be in full contact with the molecular sieve adsorbent to obtain o-chlorotoluene with the mass fraction greater than or equal to 99.95%, and carrying out desorption treatment on the molecular sieve adsorbent saturated by adsorption: heating for desorption, purging with nitrogen, and cooling. The method is easy to operate, continuous production of high-purity o-chlorotoluene can be achieved, and the high-purity o-chlorotoluene product with the mass fraction of 99.95% or above is obtained; according to the method disclosed by the invention, the raw material toluene for producing the o/p-chlorotoluene system is used as the regeneration solvent of the molecular sieve adsorbent, and the regenerated solution can be directly returned to the o/p-chlorotoluene production system, so that the recycling step of the regeneration solvent is avoided, the process route is simplified, and the treatment cost is reduced.

Description

technical field [0001] The invention relates to an adsorption separation technology, in particular to a method for continuous production of high-purity o-chlorotoluene by an adsorption separation method. Background technique [0002] Chlorotoluene is a methyl-substituted halobenzene with three isomers, namely o-chlorotoluene, m-chlorotoluene and p-chlorotoluene. Among them, o-chlorotoluene is used as an intermediate in the pesticide, pharmaceutical and dye industries. The main production process of o-chlorotoluene is: under the action of Fe catalyst, use Cl 2 It is obtained by chlorination on the toluene ring. Due to the poor selectivity of the Fe catalyst, the chlorinated product produces p-chlorotoluene in addition to o-chlorotoluene. The boiling point difference between o-chlorotoluene and p-chlorotoluene is only about 3°C, and conventional separation techniques cannot obtain high-purity (≥99.95%) o-chlorotoluene. [0003] At present, the product purity of o-chlorotolu...

Claims

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Application Information

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IPC IPC(8): C07C17/389C07C25/02
CPCC07C17/389C07C25/02Y02P20/584
Inventor 陈献乔旭杨烨崔咪芬陶文平年立春刘清齐敏周哲徐希化
Owner NANJING UNIV OF TECH
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