PROCESS FOR RECOVERING METAL CATALYST FROM MOTHER LIQUOR IN SYNTHESIS OF CARBOXYLIC ACID, RAFFINATE 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, an aqueous mixture produced by the process, a raffinate stream produced by the process, an extract stream produced by the process, a recovered extraction solvent stream produced by the process, a high boiling point organic impurities 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) separating organic impurities with a water-solvent solution from the super concentrated mother liquor stream in a solid-liquid separation zone to form an aqueous stream and a second aqueous stream; (d) mixing water and optionally an extraction solvent with the aqueous stream and the second aqueous stream in a mixing zone to form an aqueous mixture; (e) adding an extraction solvent to the aqueous mixture in an extraction zone to form an extract stream and a raffinate stream; and (f) separating the extract stream in a separation zone to form a high boiling point organic impurities stream and a recovered extraction solvent stream.