RECOVERY METHOD OF EFFECTIVE INGREDIENT FROM CRUDE MALEIC ANHYDRIDE

摘要

PURPOSE: A recovery method of an effective ingredient from crude MA(maleic anhydride) effluent is provided. Thereby, effective ingredients such as, MA, citraconic anhydride, benzoic acid, phthalic anhydride are recovered from the effluent are recovered as converting fumalic acid into MA, and they are recycled. CONSTITUTION: Maleic anhydride(MA) is generated from a manufacturing process of Phthalic anhydride(PA) by Ortho-Xylene(OX). MA is prepared by: converting fumalic acid contained in crude MA effluent into maleic acid by adding Bronsted acid as a catalyst, with reflux at 160-200°C, under normal pressure, for 7-10 hours. Wherein, Bronsted acid is selected from sulphuric acid, phosphoric acid and p-toluicsulfonic acid. Isomerization temperature is preferably 190°C and reaction time is preferably 8 hours.