Process for the preparation of ethylene glycol from sugars
A process for the preparation of ethylene glycol comprising the steps of hydrogenating a composition comprising C 2 -oxygenate compounds in the gas phase in the presence of a catalyst.
1. A process for gas-phase preparation of ethylene glycol, comprising contacting a C 1-3 -oxygenate gaseous feed composition with a catalyst and hydrogen in the gas phase, and producing a product composition comprising C 1 -C 3 glycols, optionally, further hydrogenating the product composition.
2. A process according to claim 1 , wherein the feed composition comprises glycolaldehyde.
3. A process according to claim 1 , wherein the feed composition further comprises at least one oxygenate compound selected from the group consisting of formaldehyde, glycolaldehyde, glyoxal, pyruvaldehyde and acetol.
4. A process according to claim 1 , wherein the catalyst comprises a metal component selected from one or more of the group consisting of Cu, Ni, Co, Mo, Fe, Pt, Pd, Ru, Rh, and Ir.
5. A process according to claim 1 , wherein the catalyst comprises a support selected from one or more of the group consisting of carbon, silica, alumina, silicon carbide, titania, and zirconia.
6. A process according to claim 1 , wherein the feed composition comprises C 2 -oxygenate compounds which are hydrogenated at a temperature from 150° C. to 350° C.
7. A process according to claim 6 , wherein the feed composition comprises C 2 -oxygenate compounds which are hydrogenated at a pressure from 0.1 bar to 30 bar.
8. A process according to claim 1 , wherein the product composition is subsequently hydrogenated in the presence of a catalyst, hydrogen and a solvent to produce a product stream.
9. A process according to claim 8 , wherein the solvent is selected from the group consisting of water, alcohol and water and alcohol.
10. A process according to claim 9 , wherein the alcohol is selected from one or more of the group consisting of methanol, ethanol, ethylene glycol and propylene glycol.
11. A process according to claim 8 , wherein the catalyst for the subsequent hydrogenation comprises a metal component selected from the group consisting of ruthenium, ruthenium alloy, palladium, platinum and nickel.
12. A process according to claim 8 , wherein the product stream is purified.
13. A process according to claim 1 , wherein propylene is produced at a yield of 50% or greater.
14. A process according to claim 1 , wherein 1,2-butanediol and ethylene glycol are produced in a wt/wt ratio equal to or less than 0.01:1.
15. A process according to claim 1 , wherein the C 1-3 -oxygenate feed composition further comprise one or more oxygenate compounds selected from the group consisting of glycolaldehyde and glyoxal.
16. A process for the preparation of ethylene glycol in the gas phase, comprising:
pyrolysing a sugar to obtain a pyrolysis product comprising C 1-3 -oxygenate compounds; followed by hydrogenating the pyrolysis product comprising the C 1-3 -oxygenate compounds according claim 1 .
17. The process according to claim 16 , wherein the sugar is one or more compounds selected from the group consisting of glucose, sucrose, fructose, xylose, mannose, arabinose and galactose.
18. The process according to claim 16 , wherein the pyrolysis product comprising C 1-3 -oxygenate compounds comprises at least formaldehyde and one or more oxygenate compounds selected from the group consisting of glycolaldehyde, glyoxal, pyruvaldehyde and acetol.
19. The process according to claim 16 , wherein the pyrolysis product comprising C 1-3 -oxygenate compounds comprises at least 10 wt % C 2 -oxygenate compound.
20. The process according to claim 16 , wherein the pyrolysis product is hydrogenated without prior condensation of the pyrolysis product.
21. The process according to claim 1 , wherein the feed composition comprises formaldehyde.
22. The process according to claim 2 , wherein the feed composition further comprises formaldehyde.