Preparation and purification methods of high-purity solid glycolic acid

• Main Authors: YIN GUOHUA, CHENG LIHUA, JIA RONGRONG, WANG HONGFEI, ZHANG LIPENG, CHEN YINXIA, ZHANG HAIYAN, LANG BAOAN, LIU XU
• Format: Patent
• Language: English
• Published: 04.03.2015
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

The invention relates to preparation and purification methods of high-purity solid glycolic acid. The methods comprise the steps of hydrolyzing hydroxy acetonitrile under acidic conditions, neutralizing remaining acid with ammonia water, adding anhydrous ethanol and an inhibitor into material liquid, then, cooling to remove ammonium sulfate, then, concentrating an aqueous solution of glycolic acid and ethanol at a low temperature until ethanol is completely recovered, and then, carrying out cooling filtration, thereby obtaining high-purity solid glycolic acid. The methods are particularly applicable to the extraction of high-purity glycolic acid from an inorganic salt-containing glycolic acid aqueous solution; the methods are free from adverse effects on environments and belong to green and environment-friendly processes.