Method for adopting melting crystallization technology to separate and purify succinonitrile

Abstract

The invention relates to a method for adopting a melting crystallization technology to separate and purify succinonitrile. According to the method, succinonitrile coarse products are added into a melting crystallizer and heated to 59 DEG C for complete dissolution, then programmed heating is started to raise the temperature to 45-52 DEG C, after the temperature is stabilized for 10-180 min, crystallization mother liquor is released, and succinonitrile coarse crystals are obtained; then programmed heating is started, sweating is conducted, the temperature is stabilized for 10-180 min after reaching final sweating temperature, and high-purity succinonitrilee crystals with the purity of 99.95% or above are obtained. According to the method, a separation method of melting crystallization is adopted, no solvents or vacuum drying is needed, and the operation time is short; the operation is simple, the method is environmentally friendly, the product purity is high, and the crystallization mother liquor and sweating liquid can be recycled and purified again through melting crystallization; compared with an existing decompression batch distillation method, the energy consumption, operatingtemperature and cost are low, no polymerization coking phenomena occur in the operating process, and the yield and quality are not affected.

Description

Technical field [0001] The invention belongs to the technical field of succinonitrile production for lithium ion batteries, and specifically relates to a method for separating and purifying succinonitrile by using a melt crystallization technology. Background technique [0002] The rapid development of the electronics industry has enabled us to enter the era of informationization and digitalization, which has led to an increasing demand for electronic products, which has also made our demand for lithium-ion batteries increase year by year. Bridgestone of Japan developed the first-generation electrolyte additive for lithium-ion batteries in 2002. This additive partially improved the high-temperature performance, cycle performance and safety performance of lithium-ion batteries, and laid the foundation for this. Lithium-ion battery electrolyte additives have the characteristics of strong pertinence and low dosage, which can significantly improve the performance of the battery witho...

AI Technical Summary

Problems solved by technology

Purification of succinonitrile by crystallization needs to consume a large amount of solvent, and the requirement for the purity of the solvent is relatively high. It needs to be a high-purity solvent and consumes a lot of energy; the purification of succinonitrile by adsorption method has a purity of less than 99.95% after purification of succinonitrile, and the adsorption purification The process has strict requirements on the adsorbent, the adsorbent does not have any soluble impurities, the adsorbent is difficult to recycle, the solid waste generated is difficult to handle and causes new environmental pollution, the operation is more complicated, and the operating cost is high; The distillation method is simple to operate and low in cost, but the temperature in the purification process is high, which is easy to cause polymerization and coking, etc., which affects the product yield and quality