Process for extracting neopentyl glycol and Tishchenko ester from neopentyl glycol waste liquor

Abstract

The invention provides a process for extracting neopentyl glycol and Tishchenko ester from neopentyl glycol waste liquor. According to the process, ferric ions are removed from the waste liquor by means of adding alkali liquor under moderate conditions prior to carrying out distillation on the waste liquor, so that the purity of the product is improved, and the chromaticity index of the product isincreased. Rectification is carried out at a relatively low temperature (not exceeding 160 DEG C) during rectifying, and thus, the Tishchenko ester is prevented from heated decomposition, so that theyield of the Tishchenko ester is increased by 30% or more; the Tishchenko ester cannot be decomposed to generate new impurities, and thus, the difficulty of purification of the neopentyl glycol and the Tishchenko ester is greatly lowered. Through adding butyl butyrate, gasifying the butyl butyrate by using heat carried by a distilled neopentyl glycol crude product, condensing the gasified butyl butyrate, and mixing the condensed butyl butyrate with a gas phase of the neopentyl glycol crude product at a T-shaped interface so as to form a butyl butyrate solution of the neopentyl glycol, the problem that a pipeline is blocked due to the fact that the neopentyl glycol is crystallized at a temperature below 130 DEG C is solved; compared with a steam-tracing crystallization preventing method, aheating process for the pipeline is avoided, and at least 0.7t of steam can be saved per hour, so that the production cost is reduced, and the economic benefit is increased. After distillation of theneopentyl glycol crude product is completed, the butyl butyrate is recycled as a recrystallization solvent, and the neopentyl glycol product in line with standards can be obtained directly by a method of direct gradual cooling, slow separation by crystallization and filtering separation. The overall energy consumption is only about 1 / 2 that of a rectification tower rectifying process.

Description

technical field [0001] The invention belongs to the technical field of petrochemical industry, and relates to the technical application of neopentyl glycol raffinate, a by-product of neopentyl glycol produced by a hydrogenation method, in particular to a process for extracting neopentyl glycol and gischenko ester in neopentyl glycol waste liquid. Background technique [0002] Neopentyl glycol, referred to as NPG, is a white crystalline solid, mainly used in the production of plasticizers and surfactants for unsaturated resins, oil-free alkyd resins, polyurethane foams and elastomers, and can also be used to synthesize insulating materials, Printing inks, polymerization inhibitors, synthetic aviation lubricating oil additives, etc. are important chemical raw materials. Domestic neopentyl glycol has long been in short supply and relies on imports. Neopentyl glycol monohydroxypivalate, also known as gischenko ester, 1115 ester, can be used to prepare synthetic resins, unsaturat...

AI Technical Summary

Problems solved by technology

And by adding butyl butyrate, use the heat carried by the distilled crude neopentyl glycol to vaporize the butyl butyrate, and after condensation, mix with the crude neopentyl glycol at the "T" interface to form a new The butyl butyrate solution of pentylene glycol solves the problem of neopentyl glycol crystallization below 130°C to block the pipeline. Compared with the method of preventing crystallization by steam tracing, the heating process of the pipeline is omitted, and at least Save 0.7t of steam, reduce production costs and increase economic benefits

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