Organic compounds -- part of the class 532-570 series – Organic compounds – Oxygen containing
Reexamination Certificate
2001-10-23
2002-11-12
Barts, Samuel (Department: 1621)
Organic compounds -- part of the class 532-570 series
Organic compounds
Oxygen containing
C568S861000, C568S862000, C568S864000
Reexamination Certificate
active
06479713
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to methods and compositions for hydrogenolysis of carbon sugars and sugar alcohols and hydrogenation of lactic acid.
BACKGROUND OF THE INVENTION
Currently, many of the chemicals in common use are derived from petroleum feedstocks. However, petroleum is present in limited underground reserves, and the extraction, transportation, and refining of petroleum can have severe environmental consequences.
Bio-based feedstocks, on the other hand, can be obtained from plants and can be processed by biological processes such as fermentation. To more fully utilize bio-based materials, it is often necessary to convert the fermentation products or other bio-based feedstocks into other chemicals that can be used in a variety of processes and products. Thus, it is an object of the present invention to provide new methods of converting sugars, sugar alcohols and other small molecules into a variety of desired chemical products.
For a long time, scientists and engineers have sought to convert sugars and sugar alcohols into other chemical products. For example, Conradin et al. in U.S. Pat. No. 2,852,270 (filed in 1957) reported that for increased production of propylene glycol, hydrogenolysis should be conducted over a Ni/Cu catalyst on a carrier such as magnesium oxide.
In U.S. Pat. No. 3,030,429 (filed in 1959), Conradin et al. stated that hydrogen splitting of saccharose to glycerol and glycols can be carried out in the presence of practically any technically feasible catalyst, provided that sufficient alkali is added to ensure a pH of 11 to 12.5. In one example, it was reported that hydrogenolysis of an aqueous saccharose solution over a nickel-on-kieselguhr catalyst proceeded with an 83% conversion to a product containing 43% glycerol and 25% propylene glycol.
Sirkar in U.S. Pat. No. 4,338,472 (filed in 1981) reported sorbitol hydrogenolysis to produce glycerol over a nickel-on-kieselguhr catalyst in which an alkali promoter was added to the feedstream to control pH and prevent leaching of nickel from the catalyst.
Tanikella in U.S. Pat. No. 4,404,411 (filed in 1983) described the hydrolysis of sorbitol and xylitol in nonaqueous solvents containing at least 10 mole % base. The catalyst used in the examples was nickel on silica/alumina. Distribution of ethylene glycol, propylene glycol and glycerol were reported.
Gubitosa et al. in U.S. Pat. No. 5,600,028 (filed in 1995) discussed the hydrogenolysis of polyhydric alcohols, such as sorbitol, over a ruthenium-on-carbon catalyst. In the examples, Gubitosa et al. reported that 100% of the sorbitol can be converted, with 41 to 51% of the product carbon atoms in propylene glycol.
Despite these and other efforts, there remains a need for new methods of converting sugars and sugar alcohols to smaller molecules that have a variety of uses. There is also a need for novel methods of converting molecules such as xylitol and lactic acid into higher value products such as propylene glycol and 1,3-propanediol. There is especially a need for new methods of such conversions that provide better yield and more desirable product distributions.
SUMMARY OF THE INVENTION
The invention provides a method of hydrogenolysis of an oxygen-containing organic compound, comprising: reacting an aqueous oxygen-containing organic compound with hydrogen at a temperature of at least 120° C., and in the presence of a solid catalyst; where the solid catalyst comprises a Re-containing multimetallic catalyst, and where there is at least 25% as much C—O hydrogenolysis occurs as C—C hydrogenolysis. In some preferred embodiments, at least 100% as much C—O hydrogenolysis occurs as C—C hydrogenolysis. In some preferred embodiments, these percentages (such as 25%) refer to the total amount of hydrogenolysis, in other embodiments, they refer to rates, for example, the rate of C—O hydrogenolysis is at least 25% as fast as the rate of C—C hydrogenolysis. It has been surprisingly discovered that a Ni/Re catalyst is superior to other catalysts.
The present invention also provides a hydrogenolysis method in which a 6 carbon sugar, a 6 carbon sugar alcohol, or glycerol is reacted with hydrogen, at a temperature of at least 120° C., and in the presence of a solid catalyst comprising a rhenium-containing multimetallic catalyst.
In a second aspect, the invention provides a composition of matter comprising: a solid rhenium-containing multimetallic catalyst; water, hydrogen; and a 6 carbon sugar, a 6 carbon sugar alcohol or glycerol.
In another aspect, the invention provides a method of improving the catalytic activity or selectivity of a supported metal catalyst for the reaction of hydrogen with a 6-carbon sugar, a 6-carbon sugar alcohol, or glycerol. In this method, rhenium is incorporated in a metal catalyst to form a rhenium-containing multimetallic metal catalyst. The Re-containing catalyst is reduced prior to, or simultaneous with a hydrogenolysis reaction. Preferably, the reduction is carried out by exposing the catalyst to hydrogen gas. Preferably, the 6-carbon sugar or a 6-carbon sugar alcohol is exposed to hydrogen and a rhenium-containing multimetallic metal catalyst under conditions sufficient to convert at least 40% of the sugar or sugar alcohol to propylene glycol, glycerol, ethylene glycol or any combination thereof. Here, “improving” means that at the same conditions where the rhenium-containing multimetallic catalyst results in 80% conversion, the yield of propylene glycol (“PG”) is improved by at least 5%, as compared with running the same reaction over each of: the same catalyst without rhenium, the same catalyst without rhenium but containing added weight of metal equal to the weight of rhenium in the improved method, and the same catalyst without rhenium but containing added moles of metal equal to the moles of rhenium in the improved method.
In yet another aspect, the invention provides a method of improving the reaction of hydrogen with a 6 carbon sugar or a 6 carbon sugar alcohol. In this method, the 6 carbon sugar, or a 6 carbon sugar alcohol is exposed to hydrogen and a rhenium-containing multimetallic metal catalyst under conditions sufficient to convert at least 40% of the sugar or sugar alcohol to propylene glycol, glycerol, ethylene glycol or any combination thereof. In this method, “improving” means that when tested with a 20 weight % glycerol in aqueous solution with 2 weight % sodium hydroxide, 1200 psi (8.2 MPa) hydrogen in a batch reactor for four hours, the yield of PG is improved by at least 5%, as compared with running the same reaction over each of: the same catalyst without rhenium, the same catalyst without rhenium but containing added weight of metal equal to the weight of rhenium in the improved method, and the same catalyst without rhenium but containing added moles of metal equal to the moles of rhenium in the improved method.
In another aspect, the invention provides a hydrogenolysis method in which a 5 carbon sugar, a 5 carbon sugar alcohol, lactate or lactic acid is reacted with hydrogen, at a temperature of at least 120° C., and in the presence of a solid rhenium-containing multimetallic catalyst.
In yet a further aspect, the invention provides a composition of matter comprising: a solid rhenium-containing multimetallic catalyst, water, hydrogen, and a 5 carbon sugar, a 5 carbon sugar alcohol; lactate or lactic acid.
In another aspect, the invention provides a method of making propylene glycol, comprising: reacting a composition comprising lactate or lactic acid with hydrogen in the presence of a catalyst; where acid is added to the composition prior to the step of reacting; where the lactate or lactic acid is converted with a yield of at least 60%; and wherein the PG selectivity is at least 80%.
In a further aspect, the invention provides a method of improving the reaction of hydrogen with a 5 carbon sugar, a 5 carbon sugar alcohol, lactate or lactic acid. In this method, a 5 carbon sugar, a 5 carbon sugar alcohol, lactate and lactic acid is reacted with hydrogen in the presence of a solid, rhenium
Frye, Jr. John G.
Miller Dennis J.
Werpy Todd A.
Zacher Alan H.
Barts Samuel
Battelle (Memorial Institute)
May Stephen R.
Price Elvis O.
Rosenberg Frank S.
LandOfFree
Hydrogenolysis of 5-carbon sugars, sugar alcohols, and other... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Hydrogenolysis of 5-carbon sugars, sugar alcohols, and other..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Hydrogenolysis of 5-carbon sugars, sugar alcohols, and other... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2979513