Method and device for continuous production of polyols for polyester

Abstract

The invention relates to a method and a device for continuously producing polyols for polyester. The device includes: a raw material metering pump, a liquid caustic metering pump, a mixer, a pH detector, a multi-channel reactor, a temperature controller, a neutralization tank and a product tank. The device of the present invention adopts a multi-channel reactor for condensation reaction, which can effectively control the feed ratio of the reaction process, control the reaction heat and reaction temperature; the reactor and the reaction tube are provided with turbulence devices, which can realize the mixed flow of the reaction fluid in the whole process , has a good mass transfer effect; the mixed concentration of the reactants is uniform, can achieve a uniform reaction, and effectively suppress the occurrence of various side reactions; the instrument for controlling the reaction can be accurately controlled for the reaction process parameters, the process is stable, and the product yield is high. ;The condensation reaction system is a closed reaction, which has high safety performance; the continuous reaction system can realize large-scale to a large extent; the reaction system does not add water, which reduces energy consumption and sewage discharge.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and in particular relates to a method and a device for continuously producing polyols for polyester. Background technique [0002] Polyester polyols are usually formed by condensation (or transesterification) of organic dicarboxylic acids (anhydrides or esters) and polyols (including diols) or by polymerization of lactones and polyols. Its raw material polyols include ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, pentaerythritol, 1,4-butanediol, etc. The polyhydric alcohol involved in the present invention is neopentyl glycol, trimethylolpropane, pentaerythritol, and its production principle is the same, and production process is similar, and domestic industrialized production method is one-step method, is batch reaction, and aldehyde under alkaline condition Formed by condensation of aldehydes. In the reaction process, the mass transfer a...

AI Technical Summary

Problems solved by technology

In the reaction process, the mass transfer and heat transfer effect is poor, there are many side reactions, and the reaction conversion rate is low; a certain amount of desalted water is added to the reaction system to control the reactant formaldehyde to participate in the reaction at a low concentration, resulting in the consumption of a large amount of steam during dehydration and the generation of Greater than the same amount of sewage; intermittent production, batch control differences, affecting the stability of product quality; kettle reaction, the reactor cannot be enlarged without limit, and at the same time, the degree of automation is low, the device takes up a large space, and it is difficult to achieve tens of thousands of tons Disadvantages such as production scale

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