Process for the preparation of gamma-valerolactone
Gamma-valerolactone is prepared from a levulinic acid ester in a continuous process where a stream of the levulinic acid ester together with a gaseous stream of a hydrogen-containing gas is contacted with a hydrogenation catalyst, where the levulinic acid ester is in the liquid phase, and where the hydrogenation catalyst is a solid particulate catalyst including at least one hydrogenating metal, supported on an oxide carrier.
1. A continuous process for the preparation of gamma-valerolactone (GVL) from a levulinic acid ester comprising:
contacting a stream of the levulinic acid ester together with a gaseous stream of a hydrogen-containing gas with a hydrogenation catalyst,
wherein the levulinic acid ester is in the liquid phase,
wherein the hydrogenation catalyst is a solid particulate catalyst comprising at least one hydrogenating metal, supported on an oxide carrier, and
which is conducted in the absence of solvent.
2. The process according to claim 1 , wherein the hydrogenating metal in the hydrogenation catalyst is selected from the group consisting of one or more of the metals of groups 8 to 11 of the Periodic Table of Elements.
3. The process according to claim 1 , wherein the levulinic acid ester is an alkyl levulinate.
4. The process according to claim 1 , which is conducted at a temperature in the range of 75 to 400° C.
5. The process according to claim 1 , wherein the hydrogenation catalyst comprises nickel as hydrogenating metal.
6. The process according to claim 5 , wherein the hydrogenation catalyst comprises nickel in an amount of 1 to 75% wt, calculated as metal and based on the hydrogenation catalyst.
7. The process according to claim 5 , wherein the hydrogenation catalyst comprises a platinum-group metal as dopant.
8. The process according to claim 1 , wherein the hydrogenation catalyst comprises copper as hydrogenating metal.
9. A continuous process for the preparation of gamma-valerolactone (GVL) from a levulinic acid ester comprising:
contacting a stream of the levulinic acid ester together with a gaseous stream of a hydrogen-containing gas with a hydrogenation catalyst,
wherein the levulinic acid ester is in the liquid phase,
wherein the hydrogenation catalyst is a solid particulate catalyst comprising at least one hydrogenating metal, supported on an oxide carrier,
wherein the hydrogenation catalyst comprises copper as hydrogenating metal, and
wherein the hydrogenation catalyst comprises a zinc compound as dopant.
10. The process according to claim 9 , wherein the hydrogenation catalyst comprises copper in an amount of 1 to 75% wt, calculated as metal and based on the hydrogenation catalyst.
11. A continuous process for the preparation of gamma-valerolactone (GVL) from a levulinic acid ester comprising:
contacting a stream of the levulinic acid ester together with a gaseous stream of a hydrogen-containing gas with a hydrogenation catalyst,
wherein the levulinic acid ester is in the liquid phase,
wherein the hydrogenation catalyst is a solid particulate catalyst comprising at least one hydrogenating metal, supported on an oxide carrier, and
wherein the hydrogenation catalyst comprises a platinum-group metal as hydrogenating metal and, optionally, tin or a tin compound as dopant.
12. The process according to claim 11 , wherein the platinum group metal is platinum.
13. The process according to claim 11 , wherein the hydrogenation catalyst comprises a platinum group metal in an amount of 0.1 to 7.5% wt, calculated as metal and based on the hydrogenation catalyst.
14. The process according to claim 11 , wherein the hydrogenation catalyst comprises tin or a tin compound in an amount of 20 to 200% wt, calculated as metal and based on the platinum-group metal.
15. The process according to claim 9 , wherein the oxide carrier contains an alkali metal.
16. The process according to claim 15 , wherein the alkali metal is potassium.
17. The process according to claim 15 , wherein the amount of alkali metal is in the range of 0.2 to 10% wt, calculated as element and based on the oxide carrier.
18. The process according to claim 11 , wherein the oxide carrier is selected from the group consisting of alumina, silica, zirconia, titania and mixtures thereof.
19. The process according to claim 5 , wherein the hydrogenation catalyst is supported on a carrier of aluminum oxide.