Method for preparing p-chlorotoluene and o-chlorotoluene by chlorination toluene

A technology of p-chlorotoluene and o-chlorotoluene, applied in chemical instruments and methods, preparation of halogenated hydrocarbons, organic chemistry, etc., can solve problems such as environmental pollution, achieve the effects of saving investment, facilitating maintenance, and reducing operating costs

Inactive Publication Date: 2009-08-05
江苏钟腾化工有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] In recent years, the production and development of chlorotoluene in my country has ma

Method used

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  • Method for preparing p-chlorotoluene and o-chlorotoluene by chlorination toluene
  • Method for preparing p-chlorotoluene and o-chlorotoluene by chlorination toluene
  • Method for preparing p-chlorotoluene and o-chlorotoluene by chlorination toluene

Examples

Experimental program
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Example Embodiment

[0030] Example 1:

[0031] Toluene a: 7.6 tons, dried by dryer 1 at a flow rate of 2.5 tons / hour, and then flowed into batching tank 2, adding 1000g of co-catalyst sulfur, fully stirring and pumping into chlorination tower 3, and chlorine gas flowing into chlorination at a flow rate of 0.9 tons / hour Tower 3, cyclic chlorination reaction, the reaction mole of chlorine and toluene is 1:1, the reaction temperature is controlled at 67℃, the absolute pressure in the chlorination tower 3 is 0.07Mpa, the main component of the catalyst is ferric chloride, and the auxiliary catalyst includes Sulfur or sulfide (S 2Cl 2 ), ferric trichloride is formed by the reaction of chlorine and iron ring in the chlorination process. The chlorination tower 3 is a fixed-bed tower reactor with a catalyst iron ring stacked in the lower part of the tower. Chlorine gas enters the reactor from six different positions in the lower part of the tower. The chlorination liquid is cyclically chlorinated, and the out...

Example Embodiment

[0036] Example 2:

[0037] Toluene a 9.5 tons, dried by dryer 1 at a flow rate of 2.0 tons / hour, flow into the batching tank 2, add 2000g of co-catalyst sulfur, fully stir and pump into the chlorination tower 3, and chlorine gas at a flow rate of 0.5 tons / hour into the chlorination tower 3. Cyclic chlorination reaction, the reaction mole of chlorine b and toluene a is 0.8:1, the reaction temperature is controlled at 32°C, and the internal pressure of the chlorination tower 3 is 0.06Mpa (absolute pressure). The content of the chlorinated solution is checked regularly, and the chlorination reaction is stopped when the index is reached. The hydrogen chloride gas passes through the absorption device to obtain 9.39 tons of hydrochloric acid with a concentration of 31.5%wt. The chlorinated solution is distilled and detoluene to obtain 10.22 tons of mixed chlorinated toluene, and 0.08 tons of residue is removed. 2.0 tons of toluene obtained from detoluene will be recycled for next time. ...

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Abstract

The invention provides a method for preparing p-chlorotoluene and o-chlorotoluene by toluene chlorination. The method comprises the following steps that: after raw material toluene is dried in a drier, the raw material toluene and chlorine are directly chlorinated in the presence of a catalyst so as to obtain mixed chlorotoluene, by-product hydrochloric acid and minor residual; and the mixed chlorotoluene obtained by the chlorination process is used as a raw material to be delivered to a process for separating the mixed chlorotoluene so as to obtain the o-chlorotoluene, the o-chlorotoluene and minor residual liquid through precise fractionating. By the method, a tower type fixed bed circulating chlorination process ensures that gas and liquid are contacted more sufficiently, reaction heat energy can be removed in time, so the reaction effect is better, side products are reduced, and the problem of environmental pollution caused by leakage of chlorine hydride gas in a positive pressure or normal pressure system in the prior absorbing process can be solved. Generation of wastewater is prevented, a rectifying separation mode of two serially connected towers reduces assembly height of the tower and improves separation efficiency, and purities of final products, namely p-chlorotoluene and o-chlorotoluene are both more than or equal to 99.9 percent by weight.

Description

technical field [0001] The invention belongs to a method for producing p-chlorotoluene and o-chlorotoluene by chlorination of toluene, in particular to a method for producing mixed-chlorotoluene by chlorination of toluene and separation of mixed-chlorotoluene for producing high-purity p-chlorotoluene and o-chlorotoluene. Background technique [0002] Both p-chlorotoluene and o-chlorotoluene are very important raw materials for fine organic chemicals. In recent years, the production of many new types of intermediates such as pharmaceuticals, pesticides, and dyes use them as starting materials. These intermediates show very bright development prospects , domestic and foreign markets are unanimously optimistic. The huge development space of the downstream market stimulates and promotes the production and development of chlorotoluene. [0003] There are two main methods for the industrial synthesis of chlorotoluene, one is the direct chlorination method using toluene as raw mat...

Claims

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Application Information

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IPC IPC(8): C07C25/02C07C17/12C07C17/383
Inventor 钟华陆敏山刘巧宝孙建平潘晓鑫
Owner 江苏钟腾化工有限公司
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