Method for recovering and purifying propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate from electronic waste liquid

Abstract

The invention discloses a method for recovering and purifying propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate from electronic waste liquid, and relates to the field of solvent recovery and purification. The method comprises the following steps: S1, taking mixed waste solvents propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, adding an impurity removal reactant, and carrying out reaction through a mixing mechanism to remove impurities and other impurities; S2, adding the mixed solution of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate into an organic solvent which forms azeotropy with water, distilling at the temperature lower than the boiling point of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, distilling out water and an entrainer, and reserving a mixture of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; and S3, obtaining an entrainer water azeotrope at the tower top. According to the method, the waste propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate are recycled, the pollution degree of the waste solvent generated in electronic production to the environment is reduced, and the production cost is reduced.

Description

technical field [0001] The invention relates to the technical field of solvent recovery and purification, in particular to a method for recovering and purifying propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate from electronic waste liquid. Background technique [0002] Along with the rapid development of domestic electronic manufacturing industry and optoelectronic industry, the usage of electronic chemicals such as photoresist stripper also increases greatly, electronic grade propylene glycol monomethyl ether (PM) and propylene glycol monomethyl ether acetate (PMA) often It is mutually soluble in a certain proportion, and is used as a photoresist diluent, photoresist remover, photoresist buffer, stripping agent and Cleaning agents are used in large quantities. [0003] The solution is a mixed waste solvent of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, which has poor environmental protection, a large envir...

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Problems solved by technology

[0003] The solution is a mixed waste solvent of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate, which has poor environmental protection, a large environmental load, and high post-production costs. Some results have been achieved, but most of the stripping liquid still causes waste of resources due to its simple harmless treatment, and increases the environmental load. In order to make propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate recycle , the trace impurities must be removed, and then the two are separated. The traditional process usually uses direct rectification to remove the impurities and separate and recover the organic solvent. However, the product recovery rate of the direct rectification process is not high, and the quality of the recovered product cannot reach In addition, the current recovery process of propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate will add impurity reactants to remove impurities. The current method of removing impurities is relatively simple, and the efficiency of impurity removal is relatively low. Therefore, it is proposed A method for recovering and purifying propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate from electronic waste liquid

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