Method for separating and purifying methacrylic acid through continuous variable pressure

• Main Authors: ZHANG ZEYIN, CAI XIAOLAN, DENG LIANPING, GONG YUHUAN, TAN WEI, LI JIAXIN, FANG YANXIONG
• Format: Patent
• Language: Chinese; English
• Published: 25.10.2022
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

The invention relates to a method for separating and purifying methacrylic acid through continuous variable pressure, and aims to provide a method for effectively reducing polymerization of methacrylic acid and obtaining high-purity methacrylic acid by adopting variable pressure rectification combining a reduced pressure rectification tower and a normal pressure rectification tower and taking azeotrope of methacrylic acid and water as circulating material flow. According to the technical scheme, the method comprises the following steps: introducing a methacrylic acid aqueous solution into a mixer, and fully mixing; introducing the mixed solution into a vacuum rectifying tower, obtaining a high-purity methacrylic acid product at the bottom of the vacuum rectifying tower, and pumping an azeotrope of methacrylic acid and water collected at the top of the tower into a normal-pressure rectifying tower through a pipeline; the wastewater is discharged from the top of the normal-pressure rectifying tower, concentrate