QUENCHING PROCESS OF REACTION PRODUCT GAS CONTAINING METHACRYLIC ACID AND TREATMENT METHOD OF QUENCHED LIQUID

摘要

In order to recover methacrolein and/or methacrylic acid by quenching a reaction product gas obtained by catalytic oxidation of isobutylene or the like, the reaction product gas is charged into a quench column through a double-wall pipe and is then brought into contact with a condensate as a cooling medium. Deposition of terephthalic acid and the like inside the column is prevented by controlling the temperature of a bottom in the quench column and that of an overhead gas of a quench column unit. An aromatic carboxylic acid, aromatic aldehyde, metal powder is added to an aqueous solution of methacrylic acid, which contains terephthalic acid and the like, so that the terephthalic acid and the like are caused to precipitate for their removal.