METHOD FOR PRODUCING GLYCOLIC ACID
A method for producing glycolic acid includes selectively hydrogenating glyoxylic acid using a catalyst comprising at least one transition metal element, the glycolic acid produced, which has a bio-based carbon content of above 50%. A method for preparing a composition selected from the group consisting of cosmetics, home care products, personal care products, textiles, food, beverages, drugs, fragrances, inks, or paints includes adding the glycolic acid to the composition.
1 . A method for producing glycolic acid comprising selectively hydrogenating glyoxylic acid, wherein the glycolic acid is selectively hydrogenated in the presence of a catalyst comprising at least one transition metal element.
2 . The method according to claim 1 , wherein the catalyst is a heterogeneous catalyst.
3 . The method according to claim 1 , wherein glyoxylic acid is selectively hydrogenated in the presence of a reaction medium.
4 . The method according to claim 3 , wherein the reaction medium consists of water.
5 . The method according to claim 3 , wherein the reaction medium comprises water and at least one another solvent selected from the group consisting of ethanol, acetone, acetonitrile, methanol, and combinations thereof.
6 . The method according to claim 1 , wherein the catalyst is in solid form.
7 . The method according to claim 1 , wherein the transition metal element is selected from the group consisting of Fe, Co, Ni, Cu, Zn, Ru, Rh, Pd, Ag, Pt and Au.
8 . The method according to claim 1 , wherein the transition metal element is not supported on a support.
9 . The method according to claim 1 , wherein the transition metal element is supported on a support selected from the group consisting of activated carbon, Al 2 O 3 , SiO 2 , TiO 2 , ZrO 2 , molecular sieve, and combinations thereof.
10 . The method according to claim 1 , wherein the transition metal element is supported on a support, which is not a nanotube.
11 . The method according to claim 1 , wherein the catalyst is selected from the group consisting of 5 wt % Pd/C, Ni, and combinations thereof.
12 . The method according to claim 1 , wherein the glyoxylic acid is selectively hydrogenated in the presence of a hydrogen gas.
13 . The method according to claim 1 , wherein the glyoxylic acid is selectively hydrogenated at a pressure in the range of 1 atm to 50 bars.
14 . The method according to claim 1 , wherein the glyoxylic acid is selectively hydrogenated at a temperature from room temperature to 200° C.
15 . The method according to claim 1 , wherein the glyoxylic acid is selectively hydrogenated with a glyoxylic acid conversion rate of no less than 40%.
16 . The method according to claim 1 , wherein the glyoxylic acid is selectively hydrogenated with a glycolic acid selection rate of 40% to 90%.
17 . The method according to claim 1 , wherein the concentration of glyoxylic acid in the reaction medium is in the range of 1-50 wt % relative to the total weight of glyoxylic acid and the reaction medium.
18 . The method according to claim 1 , wherein the content of the catalyst is in the range of 1-20 wt % relative to the weight of the glyoxylic acid.
19 . The method according to claim 1 , wherein the glyoxylic acid is selectively hydrogenated in a duration in the range of 2-10 hours.
20 . A glycolic acid produced by or derived from the method according to claim 1 , wherein the glyoxylic acid has a bio-based carbon content of above 50%.
21 . The glycolic acid according to claim 20 having a mean isotopic 13C deviation of from −29‰ to −7‰.
22 . The glycolic acid according to claim 20 having a mean isotopic deviation of from −7‰ to −3‰.
23 . A glycolic acid with a bio-based carbon content of above 50% and below 100%.
24 . The glycolic acid according to claim 23 having a mean isotopic 13C deviation of from −29‰ to −3‰.
25 . The glycolic acid according to claim 23 having a mean isotopic deviation of from −7‰ to −3‰.
26 . (canceled)