Method for synthesizing tetramethyl ammonium bicarbonate through tank reactor in serial connection with tubular reactor

Abstract

The invention relates to a method for synthesizing tetramethyl ammonium bicarbonate through a tank reactor in serial connection with a tubular reactor. The tank reactor is in serial connection with the tubular reactor to synthesize the tetramethyl ammonium bicarbonate which is used as an electrolyzing raw material of tetramethyl ammonium hydroxide. According to the method, raw materials of dimethyl carbonate, trimethylamine and solvent methyl alcohol are pumped into a reaction kettle by a pump, reaction heat is utilized to heat the raw materials to a reaction temperature to be reacted, redundant reaction heat is moved out by a cooler, pressure generated by a reaction system self is utilized to press the raw materials into the following tubular reactor to be reacted continuously, the materials discharged out of the tubular reactor enter two stages of falling film evaporators, a solvent of the reaction system and unconverted raw materials are recycled in the first-stage falling film evaporator, methyl carbonate tetramethyl ammonium hydrolysis reaction is performed in the second-stage falling film evaporator, and methyl alcohol generated by reaction is evaporated and recycled. The method disclosed by the invention has the advantages of low operation pressure, simple synthesizing method and equipment, small floor area, low power consumption, investment conservation, continuous production and stable product quality.

Description

technical field [0001] The technology relates to a method for synthesizing tetramethylammonium bicarbonate through tank reactors connected in series with tubular reactors, belonging to the field of organic synthesis. Background technique [0002] Tetramethylamine hydroxide, also known as tetramethylamine hydroxide (TMAH), is an organic base with the strongest alkalinity. TMAH is used as a developer and etchant, and is ultra-pure in the chemical mechanical polishing (CMP) process of integrated circuits. Cleaning agent, mainly used in integrated circuit (IC) industry, liquid crystal display industry (FT-LCD), optoelectronic industry. [0003] Tetramethylammonium hydroxide is synthesized in three steps. In the first step of quaternization reaction, trimethylamine and dimethyl carbonate are used as raw materials to prepare tetramethylammonium methyl carbonate through quaternization reaction in solvent methanol; in the second step of hydrolysis reaction, tetramethyl methyl carbo...

AI Technical Summary

Problems solved by technology

The main disadvantages of preparing TMAB through a tubular reactor are (1) the synthesis reaction is an exothermic reaction, and the raw material entering the reactor needs to be preheated to a certain temperature before it can react, and the preheating of the material needs to consume steam; (2) the reaction It is difficult to remove the heat smoothly. The biggest feature of the tubular reactor is that the reaction material does not mix back in the flow direction. The inlet section of the tubular reactor has a high reaction concentration, a fast reaction speed, and a large amount of heat released by the reaction. The tubular reactor At the end, most of the reactants have been converted, the concentration of the reaction materials becomes smaller, and the heat of reaction is released very little, which makes the design of the reactor heat exchange device complex and the smooth removal of the heat of reaction is difficult.

(3) The pressure of the reaction system is high, and the equipment cost is high

However, it also has disadvantages. For example, when obtaining the same conversion rate, the volume of the required reactor is large, multiple kettles need to be connected in series, the equipment investment is large, and the reactor occupies a large area.

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