Exxon Chemical Patents, Inc.

Exxon Research and Engineering Company

James J Baiel

Larry O Jones

William D Diana

Abraham D Cohen

Magdiel Agosto

Herbert P Dengler

Constantine Tsonopoulos

Ralph Donald Gray, Jr

A process for recovering phthalic anhydride and maleic anhydride from a maleic anhydride-rich vapor phase oxidation product comprising the step of: contacting the vapor phase oxidation product with: (i) at least one by-product stream having a freezing point which is lower than the freezing point of pure phthalic anhydride; and/or (ii) a solvent having a boiling point in the range between about 150.degree. to 350.degree. C. and a freezing point of less than 40.degree. C.; wherein a vapor-to-liquid weight ratio in the range between about 2 to 20 is exhibited within the contacting means, thereby forming a liquid phase phthalic anhydride product having a phthalic anhydride concentration in the range between about 50-100 wt. % and a first vapor stream.

Method for recovering phthalic anhydride/maleic anhydride mixtures by

A process for recovering phthalic anhydride as a liquid from a vapor phase oxidation product which comprises mixing the vapor phase oxidation product having a temperature of about 130.degree. C. or greater with a first stream comprising maleic anhydride, benzoic acid present in an amount of less than 8 mole %, based on the total concentration of the first stream, and at least one compound selected from the group consisting of: citraconic anhydride and phthalic anhydride, in a rectification tower such that a substantial portion of the phthalic anhydride contained within the vapor phase oxidation product transfers from the vapor phase to a liquid phase and a substantial portion of the by-products contained in the first stream which are more volatile than phthalic anhydride transfer from the liquid phase to the vapor phase and wherein a vapor-to-liquid weight ratio in the range between about 2 to 20 is exhibited within the rectification tower, thereby forming a liquid phase phthalic anhydride product having a phthalic anhydride concentration in the range between about 50-100 wt. %.

Liquid phthalic anhydride recovery process using a rectification tower

A process for recovering phthalic anhydride as a liquid from a vapor phase oxidation product which comprises mixing the vapor phase oxidation product having a temperature in the range of about 130.degree. C. or greater with a first stream comprising maleic anhydride and/or at least one compound selected from the group consisting of: citraconic anhydride, benzoic acid and phthalic anhydride in a rectification tower such that a substantial portion of the phthalic anhydride contained within the vapor phase oxidation product transfers from the vapor phase to a liquid phase and the by-products contained in the first stream which are more volatile than phthalic anhydride transfer from the liquid phase to the vapor phase and wherein a vapor-to-liquid weight ratio in the range between about 5 to 20 is exhibited within the rectification tower, thereby forming a liquid phase phthalic anhydride product having a phthalic anhydride concentration in the range between about 50-100 wt. %, preferably 90-100 wt. %, without the formation of an intermediate solid phase.

A process for recovering phthalic anhydride as a liquid from a vapor phase oxidation product which comprises mixing the vapor phase oxidation product having a temperature of about 130.degree. C. or greater with a first stream comprising a solvent having a boiling point in the range between about 150.degree. to 350.degree. C. and a freezing point of less than 40.degree. C., and, optionally, at least one by-product selected from the group consisting of: maleic anhydride, citraconic anhydride, benzoic acid and phthalic anhydride, in a contacting means such that a substantial portion of the phthalic anhydride contained within the vapor phase oxidation product transfers from the vapor phase to a liquid phase and a substantial portion of the first stream which are more volatile than phthalic anhydride transfer from the liquid phase to the vapor phase and wherein a vapor-to-liquid weight ratio in the range between about 2 to 20 is exhibited within the contacting means, thereby forming a liquid phase phthalic anhydride product having a phthalic anhydride concentration in the range between about 50-100 wt. %., preferably 90-100 wt. %, without the formation of an intermediate solid phase.

Solvent assisted process for recovery of phthalic anhydride in the

According to the process of this invention, alcohols are recovered from aqueous acid solution by permeation of the alcohol through an organic-acid modified polymer membrane. An improved process for the manufacture of alcohols by acid absorption of olefins is also disclosed, the improvement residing in the use of an organic-acid modified polymer membrane to selectively permeate alcohols from the concentrated aqueous strong acid solution thereof co-produced in their synthesis from olefins.

Process for the recovery of alcohols using an organic acid-modified

According to the process of this invention, alcohols are recovered from aqueous acid solution by permeation of the alcohol through a perfluorinated ionomer membrane. An improved process for the manufacture of alcohols by acid absorption of olefins is also disclosed, the improvement residing in the use of a perfluorinated ionomer membrane to selectively permeate alcohols from the concentrated aqueous strong acid solution thereof co-produced in their synthesis from olefins.

Process for the recovery of alcohols using a perfluorinated ionomer

A unique combination of specially chosen entrainers, e.g., pentanes and cyclohexane, and high-pressure azeotropic distillation conditions, e.g., 100-200 psig., provides an economically efficient separation of a C.sub.2 -C.sub.5 alkyl alcohol, e.g., isopropanol, from its aqueous mixture; and also results in the production of a useable steam having a sufficient pressure, e.g., from 10 psig. to 30 psig. Preferably, said azeotropic distillation is conducted in the substantial absence of oxygen, e.g., less than 1 wppm.

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Morris Plains, NJ, United States of America

James J Baiel