Methods and systems for generating polyols
View Patent ↗Disclosed are methods for generating propylene glycol, ethylene glycol and other polyols, diols, ketones, aldehydes, carboxylic acids and alcohols from biomass using hydrogen produced from the biomass. The methods involve reacting a portion of an aqueous stream of a biomass feedstock solution over a catalyst under aqueous phase reforming conditions to produce hydrogen, and then reacting the hydrogen and the aqueous feedstock solution over a catalyst to produce propylene glycol, ethylene glycol and the other polyols, diols, ketones, aldehydes, carboxylic acids and alcohols. The disclosed methods can be run at lower temperatures and pressures, and allows for the production of oxygenated hydrocarbons without the need for hydrogen from an external source.
1. A method of generating a reaction product comprising a mixture of an alcohol and a ketone from a biomass-derived oxygenated hydrocarbon, the method comprising:
catalytically reacting an aqueous feedstock solution comprising water and at least one biomass-derived, water-soluble oxygenated hydrocarbon having two or more carbon atoms with hydrogen in the presence of a catalytic material at a temperature and a pressure to produce a reaction product comprising a mixture of an alcohol and a ketone;
wherein the catalytic material comprises:
(a) platinum, palladium, iron, ruthenium, rhenium, copper, rhodium, cobalt, nickel, iridium, an alloy of at least two of the foregoing, or a mixture of at least two of the foregoing; or
(b) a bi-functional catalyst selected from the group consisting of tungstated zirconia, titania zirconia, sulfated zirconia, acidic alumina, silica-alumina, a heteropolyacid, and combinations thereof.
2. The method of claim 1 wherein the catalytic material comprises at least one of the metals listed in (a), and wherein the catalytic material further comprises a distinct second metal selected from the group consisting of nickel, palladium, cobalt, ruthenium, copper, iron, cobalt, zinc, cadmium, gold, silver, niobium, zirconium, titanium, germanium, rhenium, manganese, chromium, molybdenum, tungsten, and tin.
3. The method of claim 2 , wherein the catalytic material further comprises a distinct third metal selected from the group consisting of copper, iron, cobalt, zinc, cadmium, gold, silver, niobium, zirconium, titanium, germanium, rhenium, manganese, chromium, molybdenum, tungsten, tin, vanadium, and tantalum.
4. The method of claim 3 wherein the catalytic material further comprises a distinct fourth metal selected from the group consisting of copper, iron, cobalt, zinc, cadmium, gold, silver, niobium, zirconium, titanium, germanium, rhenium, manganese, chromium, molybdenum, tungsten, tin, vanadium, and tantalum.
5. The method of claim 2 wherein the catalytic material further comprises a support selected from the group consisting of tungstated zirconia, titania zirconia, sulfated zirconia, phosphated zirconia, acidic alumina, silica-alumina, sulfated alumina, phosphated alumina, heteropolyacids, and mixtures thereof.
6. The method of claim 1 wherein the hydrogen reacts with the biomass-derived, water-soluble oxygenated hydrocarbon at a temperature between about 100° C. and 300° C. and a pressure between about 72 psig and 1300 psig.
7. The method of claim 1 wherein the hydrogen comprises at least one of an external hydrogen, in-situ generated hydrogen, or recycled hydrogen.
8. The method of claim 1 wherein the hydrogen comprises in-situ generated hydrogen.
9. The method of claim 8 wherein the in-situ generated hydrogen is produced by contacting a portion of the aqueous feedstock solution with a second catalytic material comprising one or more Group VIII metals under conditions sufficient to produce hydrogen.
10. The method of claim 1 wherein the biomass-derived, water-soluble oxygenated hydrocarbon comprises a member selected from the group consisting of a lignocellulose derivative, a cellulose derivative, a hemicellulose derivative, a carbohydrate, a starch, a monosaccharide, a disaccharide, a polysaccharide, a sugar, a sugar alcohol, an alditol, and a polyol.
11. The method of claim 1 wherein the reaction product further comprises unreacted oxygenated hydrocarbons.
12. The method of claim 11 wherein the unreacted oxygenated hydrocarbons are recycled and combined with the aqueous feedstock stream.
13. The method of claim 1 , wherein the reaction product further comprises a member selected from the group consisting of an aldehyde, a diol, a poloyol, a carboxylic acid, and mixtures thereof.