PROCESS FOR RECOVERING METAL CATALYST FROM MOTHER LIQUOR IN SYNTHESIS OF CARBOXYLIC ACID, SOLVENT RICH STREAM PRODUCED BY THE SAME AND PROCESS FOR PRODUCING SUPER CONCENTRATED MOTHER LIQUOR STREAM

摘要

PURPOSE: To provide a process for removing impurities and recovering a metal catalyst stream from mother liquor produced in the synthesis of carboxylic acid, which is able to enhance the impurity removal efficacy and the operability, a super concentrated mother liquor stream produced by the process, a high boiling point organic impurities stream produced by the process, a solvent rich stream produced by the process and a process for producing a super concentrated mother stream. CONSTITUTION: The process comprises the steps of (a) evaporating a mother liquor including a carboxylic acid, a metal catalyst, impurities, water and a solvent in a first evaporator zone to produce a vapor stream and a concentrated mother liquor stream; (b) evaporating the concentrated mother liquor stream in a second evaporator zone to form a solvent rich stream and a super concentrated mother liquor stream; (c) mixing a water-solvent solution with the super concentrated mother liquor stream in a mixing zone to form an aqueous mixture; (d) optionally separating organic impurities from the aqueous mixture in a solid-liquid separation zone to form a purified aqueous mixture; (e) adding an extraction solvent to the aqueous mixture or the purified aqueous mixture in an extraction zone to form an extract stream and a raffinate stream; and (f) optionally separating the extract stream and the solvent rich stream in a separation zone to form a high boiling point organic impurities stream and a recovered extraction solvent stream.