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METHOD FOR PRODUCING 4-6C DICARBOXYLIC ACID ESTERS FROM ALKALI WASTE FLUID OCCURRING IN CAPROLACTAM PRODUCTION PROCESS
METHOD FOR PRODUCING 4-6C DICARBOXYLIC ACID ESTERS FROM ALKALI WASTE FLUID OCCURRING IN CAPROLACTAM PRODUCTION PROCESS
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机译:在己内酰胺生产过程中由碱废液产生4-6C双羧酸酯的方法。
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摘要
PROBLEM TO BE SOLVED: To provide a method for efficiently carrying out recovery and production of a 4-6C dicarboxylic acid from an alkali waste fluid occurring in the production process of caprolactam and production of a useful substance such as an ester, etc. ;SOLUTION: This method for efficiently recovering and producing the objective substance from the waste fluid comprises (a) neutralizing the waste fluid with sulfuric acid, subjecting the resulting solution to phase separation and adding nitric acid to an oil phase to convert an organic substance into a dicarboxylic acid by oxidation reaction, (2) distilling a monocarboxylic acid and nitric acid at a first stage and decomposing residual nitric acid and a nitro compound at a second step by two-stage concentration to give concentrated crude product of the objective dicarboxylic acid, (3) subjecting the concentrated crude product to semiesterification with an alcohol at a first stage and obtaining crude product of the dicarboxylic acid at a second stage and (4) purifying the product by distillation.;COPYRIGHT: (C)2003,JPO
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