Continuous kettle type chlorination technology

Abstract

The invention discloses a continuous kettle type chlorination technology. The technology comprises the following steps: adding a certain amount of a solvent to each of chlorination kettles, starting a stirrer, and starting a tail gas absorption system; continuously adding 3,5-dimethylphenol, a chlorinating agent, and the solvent to a chlorination kettle A, setting the reaction temperature at 35-40DEG C, and reacting under normal pressure and stirring conditions; continuously carrying out a chlorination reaction through supplementing the chlorinating agent to a chlorination kettle B after the liquid level in the chlorination kettle A reaches an overflow port and a reaction solution flows into the chlorination kettle B, and controlling the chlorination temperature at 30-35DEG C under stirring; continuously carrying out the chlorination reaction through supplementing the chlorinating agent to a chlorination kettle C after the liquid level in the chlorination kettle B reaches an overflow port and a reaction solution flows into the chlorination kettle C, stirring, and adjusting the reaction temperature to 25-30DEG C; and completing the chlorination process through allowing a liquid in the chlorination kettle C to automatically flow into a receiving kettle after the liquid level in the chlorination kettle C reaches an overflow port. The reaction conversion rate is improved to 90-100% from 60-80% through above continuous stepped reaction, so the finished product (PCMX) yield is greatly improved, and the side reaction generation is effectively reduced.

Description

technical field [0001] The invention belongs to a basic chemical chlorination process, and in particular relates to a chlorinated process of generating alkylphenols through the action of an alkylphenol and a chlorination agent. Background technique [0002] p-Chloro-m-xylenol (that is, 4-chloro-3,5-dimethylphenol, referred to as PCMX) is recognized as a highly efficient, broad-spectrum and safe fungicide, certified by the US FDA as the preferred fungicide, widely used Used in cosmetics, paints, and leather as fungicides, anti-mildew and anti-bacterial agents. [0003] The industrial production of p-chloro-m-xylenol generally uses m-xylenol as a raw material, and cuprous chloride is used as a catalyst system to chlorinate with a chlorinating agent to generate p-chloro-m-xylenol. In the current process, one reactor is used for chlorination to obtain p-chloro-m-xylenol. Since this reaction is an exothermic reaction and the temperature required for the system is different at di...

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Problems solved by technology

This patent is a beneficial attempt for industrialization, but at the same time, it is difficult to treat the sewage after washing the reaction liquid with a large amount of washing water, which greatly increases the production cost and is not conducive to environmental protection; in addition, due to the addition of various co-catalysts, there are catalysts in the product Disadvantages of medium residue and difficult catalyst reuse

[0008] The existing processes all suffer from incomplete chlorination, which cannot convert the raw material 3,5-dimethylphenol into the target product to the greatest extent; at the same time, there are many types of by-products, high content of by-products, difficult separation of products, and subsequent processing The disadvantage of large quantity; due to the use of gap reaction, it is necessary to transfer and re-feed after each batch of materials, which increases the workload

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