Process for the preparation of ethylene glycol from sugars

1. A process for the preparation of a C 1 -C 3 hydroxy compound, comprising the steps of:

a) providing an oxygenate feed composition comprising a C 1 -C 3 oxygenate compound in a total concentration of at least 20% by weight of oxygenate feed composition; and

b) providing a chemical reactor comprising

i. an inlet zone in fluid communication with

ii. a reaction zone comprising a heterogeneous hydrogenation catalyst material in fluid communication with

iii. an outlet zone;

then

c) feeding the oxygenate feed composition of step a) to the reactor inlet zone i) of step b) to obtain an initial total concentration of C 1 -C 3 oxygenate compound of less than 20% by weight of reactor fluid in the reaction zone ii) of step b), wherein change in the total concentration of C 1 -C 3 oxygenate compound from greater than 20% by weight to less than 20% by weight is due to dilution by the reactor fluid; and

d) in the reaction zone ii) reacting the C 1 -C 3 -oxygenate compound with hydrogen in the presence of the catalyst material to obtain a C 1 -C 3 hydroxy compound; and then

e) recovering from the outlet zone iii) the hydroxy product composition comprising the C 1 -C 3 hydroxy compound,

wherein the oxygenate feed composition of step a) comprises two or more C 1 -C 3 oxygenate compounds selected from the group consisting of glycolaldehyde, glyoxal, pyruvaldehyde, acetol and formaldehyde.

2. The process according to claim 1 , wherein the total concentration of C 1 -C 3 oxygenate compound in the oxygenate feed composition is at least 25% by weight of oxygenate feed composition.

3. The process according to claim 1 , wherein the oxygenate feed composition of step a) comprises at least 20% by weight of glycolaldehyde and at least 5% by weight of pyruvaldehyde.

4. The process according to claim 1 , wherein the total concentration by weight of C 1 -C 3 hydroxy compound in the hydroxy product composition is at least 50% by weight of the total concentration C 1 -C 3 oxygenate compound in the oxygenate feed composition.

5. The process according to claim 1 , wherein the selectivity of ethylene glycol (mol/mol C 2 ) is at least 80%.

6. A process for the preparation of a C1-C3 hydroxy compound, comprising the steps of:

a) providing an oxygenate feed composition comprising a C1-C3 oxygenate compound in a total concentration of at least 20% by weight of oxygenate feed composition; and

b) providing a chemical reactor, wherein the chemical reactor is a continuously stirred tank reactor, comprising

i. an inlet zone in fluid communication with

ii. a reaction zone comprising a heterogeneous hydrogenation catalyst material in fluid communication with

iii. an outlet zone;

then

c) feeding the oxygenate feed composition of step a) to the reactor inlet zone i) of step b) to obtain an initial total concentration of C1-C3 oxygenate compound of less than 20% by weight of reactor fluid in the reaction zone ii) of step b); and

d) in the reaction zone ii) reacting the C1-C3-oxygenate compound with hydrogen in the presence of the catalyst material to obtain a C1-C3 hydroxy compound; and then

e) recovering from the outlet zone iii) the hydroxy product composition comprising the C1-C3 hydroxy compound,

wherein the oxygenate feed composition of step a) comprises two or more C1-C3 oxygenate compounds selected from the group consisting of glycolaldehyde, glyoxal, pyruvaldehyde, acetol and formaldehyde, and

wherein, the selectivity of propylene glycol (mol/mol C 3 ) is at least 60%.

7. The process according to claim 1 , wherein the hydroxy product composition of step e) comprises one or more C 1 -C 3 hydroxy compounds selected from the group consisting of methanol, ethylene glycol and propylene glycol.

8. The process according to claim 1 , wherein the C 1 -C 3 oxygenate compound is a C 2 -C 3 oxygenate compound.

9. The process according to claim 1 , wherein the C 1 -C 3 hydroxy compound is a C 2 -C 3 hydroxy compound.

10. The process according to claim 1 , wherein the catalyst material of step b) comprises a metal component selected from the group consisting of ruthenium, ruthenium alloy, rhenium, rhodium, iridium, palladium, platinum, copper and nickel.

11. The process according to claim 1 , wherein the catalyst material of step b) comprises a support material.

12. The process according to claim 1 , wherein the catalyst material of step b) comprises ruthenium on carbon or copper on carbon.

13. The process according to claim 1 , wherein the catalytic reaction of step d) is conducted under an initial hydrogen partial pressure of at least 0.5 bar.

14. The process according to claim 1 , wherein the reaction of step d) is conducted at a temperature in the range of from 50-350° C.

15. The process according to claim 1 , wherein the reaction of step d) is conducted at a temperature in the range of from 200-250° C. and a hydrogen partial pressure in the range of from 0.5 to 5 bar.

16. The process according to claim 1 , wherein the reaction of step d) is conducted at a temperature in the range of from 60-120° C. and a hydrogen partial pressure in the range of from 60 to 140 bar.

17. The process according to claim 1 , wherein step d) is conducted under conditions to provide liquid phase hydrogenation of the oxygenate compound and a solvent is present in the reaction zone of step d).

18. The process according to claim 17 , wherein the solvent comprises one or more of the compounds selected from the group consisting of water, methanol, ethanol, ethylene glycol and propylene glycol.

19. The process according to claim 1 , wherein the process is performed under continuous conditions.

20. The process according to claim 1 , wherein the reactor of step c) is a plug flow reactor.

21. The process according to claim 1 , wherein a fraction of the hydroxy product composition recovered in step e) is transferred to the reaction zone ii) of step b).

22. The process according to claim 1 , wherein the reactor of step c) is a stirred tank reactor.

23. The process according to claim 1 , wherein the hydrogenation product composition of step e) is subjected to a purification step to recover the C 1 -C 3 hydroxy compound.

24. The process according to claim 23 , wherein unreacted hydrogen recovered in the purification step, is recycled to the reaction zone ii) of step b).

25. A process for the preparation of a C 1 -C 3 hydroxy compound, comprising the steps of:

i. providing a feedstock solution of a sugar composition;

ii. exposing the feedstock of a) to thermolytic fragmentation to produce a fragmentation product composition comprising a C 1 -C 3 oxygenate compound; and

iii. optionally conditioning the fragmentation product composition; and then

iv. subjecting the fragmentation product composition of step ii) or iii) to the process according to claim 1 , wherein the fragmentation product composition is the oxygenate feed composition of step a).

26. The process according to claim 25 , wherein the sugar composition is selected from one or more of the monosaccharides fructose, xylose, glucose, mannose, galactose, arabinose; and/or the disaccharides sucrose, lactose, maltose.

27. The process according to claim 25 , wherein the feedstock solution of step i) is a solution of a sugar in a solvent comprising from 20-95 wt. % of sugar.

28. The process according to claim 25 , wherein the solvent comprises one or more of the compounds selected from the group consisting of water, methanol, ethanol, ethylene glycol and propylene glycol.

29. The process according to claim 1 , wherein the oxygenate feed of step a) comprises a C 1 -C 3 oxygenate compound in a total concentration of at least 50% by weight of oxygenate feed composition.

30. The process according to claim 29 , wherein a change in the total concentration of C 1 -C 3 oxygenate compound from greater than 50% by weight to less than 20% by weight is due to dilution by the reactor fluid.

31. The process according to claim 1 , wherein the chemical reactor is a continuously stirred tank reactor.