Process for producing gamma-butyrolactone

Claim 2

In a vapor phase process for the production of gamma-butyrolactone by passing a vaporized feed of maleic acid, maleic anhydride, succinic acid or succinic anhydride or a mixture thereof with hydrogen over a metallic catalyst capable of hydrogenolyzing a carboxylic group to a methyleneoxy group, the improvement which comprises the steps of: i. providing a vaporized mixture of (a) maleic acid, maleic anhydride, succinic acid, succinic anhydride or a mixture thereof, and (b) water at a ratio of from 10 to 60 parts by weight of acid/anhydride to 90 to 40 parts by weight of water, and ii. contacting the resulting vaporized mixture and hydrogen in the vapor phase with a metallic catalyst capable of hydrogenolyzing a carboxylic group to a methyleneoxy group.

Claim 3

A process as defined in claim 1 wherein said metal catalyst includes copper oxide, zinc oxide, chromium oxide, manganese oxide, nickel oxide or a mixture of any of the foregoing.

Claim 4

A process as defined in claim 1 wherein said catalyst has been pre-reduced with hydrogen before being contacted with said vaporized mixture and hydrogen.

Claim 5

A process as defined in claim 2 wherein said catalyst is a copper-chromite catalyst or a copper-zinc catalyst.

Claim 6

A process as defined in claim 1 wherein said vaporized mixture consists essentially of maleic acid and water.

Claim 7

A process as defined in claim 5 wherein the maleic acid consists essentially of from about 10 to about 60 percent by weight of said vaporized mixture.

Claim 8

A process as defined in claim 6 wherein said maleic acid consists essentially of from about 30 to about 40 percent by weight of said vaporized mixture.

Claim 9

A process as defined in claim 1 wherein the molar ratio of hydrogen to said maleic acid, maleic anhydride, succinic acid, succinic anhydride or mixture thereof is in excess of about 10:1.

Claim 10

A process as defined in claim 1 wherein the catalyst is in a fixed bed and is maintained at a temperature of from about 100° C. and 400° C.

Claim 11

A process as defined in claim 9 wherein the catalyst temperature is maintained at from about 150° C. to about 325° C.

Claim 12

A process as defined in claim 1 wherein the pressure is from 1 to 15 atmospheres.

Claim 13

In a vapor phase process for producing gamma-butyrolactone by passing a vaporized feed of maleic acid with hydrogen over a metallic catalyst capable of hydrogenolyzing a carboxylic group to a methyleneoxy group, the improvement which comprises the steps of: i. providing a vaporized mixture of (a) from about 10 to about 50 weight percent of maleic acid in (b) water, said mixture having a ratio of from 10 to 50 parts by weight of acid to 90 to 50 parts by weight of water, ii. contacting the resulting vaporized mixture and hydrogen in the vapor phase at a pressure of from 1 to 5 atmospheres and at a temperature between about 150° C. and 325° C. in the presence of a reduced copper-chromite or a reduced copper-zinc catalyst, iii. condensing the resulting product vapors, and iv. recovering said gamma-butyrolactone therefrom.

Claim 14

In a vapor phase process for producing gamma-butyrolactone by passing a vaporized feed of maleic acid with hydrogen over a metallic catalyst capable of hydrogenolyzing a carboxylic group to a methyleneoxy group, the improvement which comprises the steps of: i. providing a vaporized mixture of (a) from about 10 to about 50 weight percent of maleic acid in (b) water, said mixture having a ratio of from 10 to 50 parts by weight of acid to 90 to 50 parts by weight of water, ii. contacting the resulting vaporized mixture and hydrogen in the vapor phase at a pressure of from 1 to 5 atmospheres and at a temperature between about 150° C. and 325° C. in the presence of a reduced copper-chromite or a reduced copper-zinc catalyst, iii. condensing the resulting product vapors, and iv. recovering said gamma-butyrolactone therefrom.

Claim 15

A process as defined in claim 12 wherein the molar ratio of hydrogen to maleic acid is in excess of about 10:1.

Claim 16

A process as defined in claim 12 wherein said catalyst is a reduced copper-chromite catalyst having a weight ratio of between about 10:1 to 1:1 of CuO:Cr 2 O 3 prior to reduction.

Claim 17

In a vapor phase process for the production of gamma-butyrolactone by passing a vaporized feed of maleic acid, maleic anhydride, succinic acid or succinic anhydride or a mixture thereof with hydrogen over a metallic catalyst capable of hydrogenolyzing a carboxylic group, the improvement which comprises the steps of: i. providing a vaporized mixture of (a) maleic acid, maleic anhydride, succinic acid, succinic anhydride or a mixture thereof, and (b) water at a ratio of from 10 to 60 parts by weight of acid/anhydride to 90 to 40 parts by weight of water, and ii. contacting the resulting vaporized mixture and hydrogen in the vapor phase with a metallic catalyst capable of hydrogenolyzing a carboxylic group to a methyleneoxy group and which includes copper oxide, zinc oxide, chromium oxide, manganese oxide, nickel oxide or a mixture thereof, and wherein the molar ratio of hydrogen to said maleic acid, maleic anhydride, succinic acid, succinic anhydride or mixture thereof is in excess of about 10:1, the catalyst is in a fixed bed and is maintained at a temperature of from about 100° C. to 400° C., and the pressure is from 1 to 15 atmospheres.

Claim 18

In a vapor phase process for the production of gamma-butyrolactone by passing a vaporized feed of maleic acid, maleic anhydride, succinic acid or succinic anhydride or a mixture thereof with hydrogen over a metallic catalyst capable of hydrogenolyzing a carboxylic group, the improvement which comprises the steps of: i. providing a vaporized mixture of (a) maleic acid, maleic anhydride, succinic acid, succinic anhydride or a mixture thereof, and (b) water at a ratio of from 10 to 60 parts by weight of acid/anhydride to 90 to 40 parts by weight of water, and ii. contacting the resulting vaporized mixture and hydrogen in the vapor phase with a metallic catalyst capable of hydrogenolyzing a carboxylic group to a methyleneoxy group and which includes copper oxide, zinc oxide, chromium oxide, manganese oxide, nickel oxide or a mixture thereof, and wherein the molar ratio of hydrogen to said maleic acid, maleic anhydride, succinic acid, succinic anhydride or mixture thereof is in excess of about 10:1, the catalyst is in a fixed bed and is maintained at a temperature of from about 100° C. to 400° C., and the pressure is from 1 to 15 atmospheres.

Claim 19

A process as defined in claim 15 wherein said metallic catalyst is a copper-chromite catalyst or a copper-zinc catalyst which has been pre-reduced with hydrogen before being contacted with said vapors and hydrogen.