Purifying crude methanol by rectification - after decomposing methyl formate impurity by base catalysed hydrolysis

• Main Authors: KARWAT,HEINZ,.ER.NAT, JELEND,WOLFGANG,.ER.NAT
• Format: Patent
• Language: English; German
• Published: 23.02.1978
• Edition: 2
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

Purifcn. of crude methanol (I) contg. among other impurities, water, high alcohols and methyl formate (II), comprises first treating it with an alkali(ne earth) hydroxide or alkali carbonate to convert nII) to metal formate salts. The mixt. is then rectified to remove water, higher alcohols and the metal formates. Pref. the purified (I) is used to make up losses in a recycled (I) wash stream which is being used to separate gas components from a crude gas stream. A portion of the wash (I) is used to remove water from the crude gas and then free from water in a regeneration column. Where the crude (I) contains little water (some of) the water-laden wash (I) is added to the reactor where (II) is decomposed. Only one rectifier is needed, c.f. 2 in existing processes, so investment costs are reduced and regeneration of wash (I) and purificn. of crude (I) can be integrated. Any ethyl formate or methyl acetate which may be present are also removed.