Novel continuous production technique of phthalate plasticizer

Abstract

The invention relates to a novel continuous production technique of a phthalate plasticizer. The technique comprises the following steps: raw materials phthalic anhydride and monobasic alcohol and a catalyst are continuously introduced into a first-stage esterification kettle, and a small amount of monobasic alcohol is continuously introduced into a fifth-stage esterification kettle; liquid-phase materials of all stages of esterification kettles gradually flow to the fifth-stage esterification kettle from the first-stage esterification kettle via a liquid-phase pipeline and flow out of the fifth-stage esterification kettle, thereby obtaining a reaction product; gas-phase materials of all stages of esterification kettles are gradually introduced into the first-stage esterification kettle from the fifth-stage esterification kettle via a gas-phase pipeline and enter a packing tower; and the temperatures of all stages of esterification kettles are kept at 130-230 DEG C, the gage pressures are kept at 0-2atm, and the retention time is kept at 0.2-2 hours. The acid number of the bottom discharge product of the fifth-stage esterification kettle is 0.2-2.5 mg KOH / g. The novel technique for continuously producing the phthalate plasticizer greatly reduces the esterification time and energy consumption, and enhances the economic benefit.

Description

technical field [0001] The invention relates to a new process for continuous production of phthalate plasticizers. Background technique [0002] Phthalate plasticizers are the plasticizers with the largest output, the largest amount, and the most widely used varieties. It is prepared by esterification reaction with phthalic anhydride and corresponding monoalcohol as raw material under the action of catalyst. [0003] The production methods of phthalate plasticizers in industry mainly include batch method, continuous method and semi-continuous method. For plasticizers with large output, continuous production is generally adopted, and multiple CSTR reactors are used in series to carry out multi-stage esterification while maintaining excess raw material alcohol. During the reaction process, a large amount of raw material alcohol is evaporated, and then condensed and refluxed to the reaction system. The entire esterification process takes a long time and consumes a lot of ener...

AI Technical Summary

Problems solved by technology

During the reaction process, a large amount of raw material alcohol is evaporated, and then refluxed to the reaction system after condensation. The entire esterification process takes a long time and consumes a lot of energy.