Amt International Inc.

Ji-Young Jang

Kuang-Yeu Wu

Karl Tze-Tang Chuang

Kuang Wu

Pai-Yu Polly Chiang

Ming-Mou Yang

Hyung-Jin Kim

A carboxylic acid e.g. acetic acid, is recovered from an aqueous feed stream containing the corresponding ester, an alcohol and a small amount of water by catalytically dehydrating the alcohol to the corresponding ether and water, and reacting the water with the ester to generate a liquid carboxylic acid rich product stream. The acid is recovered by distillation. In a second embodiment, additional alcohol and/or water are co-fed with the feed or fed directly to a catalytic distillation column, resulting in a liquid bottom product stream of substantially pure acetic acid and a top distillate stream of substantially pure ether.

Process for recovery of a carboxylic acid from a feed stream containing the corresponding ester

A method for recovering acetic acid from an aqueous feed stream containing acetic acid and, in particular, a stream generated during terephthalic acid production includes feeding a water-rich feed stream to a liquid-liquid extraction column, which includes a guard bed near the top thereof for conversion of alcohol within the feed stream by reaction with acetic acid to the corresponding ester, and removing residual water from acetic acid in an azeotropic distillation column by feeding water-poor feed streams from the extraction column to the distillation column at a height at which the mixture has a similar water concentration. The liquid-liquid extraction column produces an extract of an extraction solvent and acetic acid which is sent to the azeotropic distillation column to separate residual water and acetic acid.

Method for recovery of acetic acid from an aqueous solution thereof

The invention disclosed is an apparatus and method for the recovery of acetic acid, azeotropic agent, extraction agent, re-usable water and other reaction products such as p-toluic acid, from an aqueous stream generated during a terephthalic acid production process, having superior energy efficiency and reduced water consumption. The apparatus of the invention includes: an azeotropic distillation column to remove water from acetic acid, a pair of mother liquor extraction columns sequentially connected in series for primary recovery of extraction solvent and other organics, an azeotropic agent stripper for recovery of azeotropic agent and a post-separation solvent stripper distillation column for further separation of the aqueous bottoms stream from said extraction columns into a volatiles stream comprising mainly organics with a very low amount of water and a liquid stream comprising water containing very low amounts of organics, each stream being sufficiently pure that it can be recycled for reuse in the purification of crude terephthalic acid.

System and method for reduction of water consumption in purified terephthalic acid production

The invention disclosed relates to an apparatus and method for recovering acetic acid from an aqueous feed stream containing acetic acid, in particular a stream generated during terephthalic acid production. The apparatus includes: a liquid-liquid extraction column to which water-rich feed streams are fed, having a guard bed situated near the top and within the extraction column for conversion by reaction with acetic acid of alcohol within the mixture to the corresponding ester; and an azeotropic distillation column to remove residual water from acetic acid, to which water-poor feed streams are fed directly at a height of the azeotropic distillation column at which the mixture therein has a similar water concentration. The liquid-liquid extraction column produces an extract comprising an extraction solvent and acetic acid which is sent to the azeotropic distillation column to separate residual water and acetic acid.

Apparatus and method for recovery of acetic acid from an aqueous solution thereof

A distillation system and method for recovering acetic acid from a feed stream containing acetic acid and water stream generated during terephthalic acid production. The invention includes a dehydration column utilizing azeotropic distillation to recover the acetic acid in conjunction with a condenser system to recover the energy.

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McKinney, TX, United States of America

Ji-Young Jang