Method for preventing polymerization reaction in methyl methacrylate preparation process

Abstract

A method for preventing polymerization in s methyl methacrylate preparation process and a polymerization inhibition composition used in the process are disclosed. The method is as follows: mixing methanol, concentrated sulfuric acid, phenothiazine and hydroquinone to form the polymerization inhibition composition; in turn introducing an amide mixture into a first esterification reactor added with methanol and water, using an overflow way to in turn enter the rest esterification reactors, and using a sequential control way to in turn add the polymerization inhibition composition to each esterification reactor one by one. The weight ratio of the methanol in the polymerization inhibition composition is higher than the weight ratio of the sum of the concentrated sulfuric acid, the phenothiazine and the hydroquinone. By adding of the polymerization inhibition composition into the esterification reactors, the polymerization reaction rate in the esterification reactors can be effectively reduced, the polymer accumulation on the top of the esterification reactors is reduced, and equipment maintenance cost of the is reduced.

Description

technical field [0001] The invention relates to the field of chemical industry, and in particular, relates to a method for preventing polymerization reaction during the preparation of methyl methacrylate. Background technique [0002] Methyl methacrylate (MMA for short) is an unsaturated ester, which is a colorless transparent liquid at room temperature, volatile, flammable, explosive, soluble in aromatic hydrocarbons and ethers, slightly soluble in Water can form azeotropes with water and methanol. Under certain conditions, self-polymerization can occur, and it is also easy to form copolymers with other monomers. Methyl methacrylate is commonly known as plexiglass monomer, which is an important organic chemical raw material and chemical product, mainly used in the production of plexiglass (that is, polymerized methyl methacrylate, referred to as PMMA), PVC Agent ACR, methyl methacrylate-styrene-butadiene copolymer (abbreviated as MBS) and the second monomer used for acryl...

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Problems solved by technology

[0007] Aiming at the problem that polymerization is prone to occur in the esterification kettle used to prepare methyl methacrylate in the related art, which leads to the inability of long-term stable operation of the preparation equipment and the large consumption of materials, the present invention proposes a The method of preventing the polymerization reaction of MMA during the preparation process can effectively slow down the rate of the polymerization reaction in the esterification tank, so that the preparation equipment can run stably for a longer period of time without shutting down for maintenance, simplifying subsequent process operations and reducing material consumption

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