Method of catalytic conversion of carbohydrates to low-carbon diols by using alloy catalysts

Patent metadata

Field	Value
Publication number	US-10654781-B2
Application number	US-201515735190-A
Country	US
Kind code	B2
Filing date	Nov 26, 2015
Priority date	Nov 12, 2015
Publication date	May 19, 2020
Grant date	May 19, 2020

Abstract

This invention provides a method for catalytic conversion of carbohydrates to low-carbon diols using alloy catalysts. In the process, carbohydrates as the feedstock are subjected to one-step catalytic conversion to realize the highly efficient and selective production of ethylene glycol etc. under hydrothermal conditions, with an alloy catalyst composed of tin, and a transition metal such as iron, cobalt, nickel, rhodium, ruthenium, palladium, iridium, platinum and copper, or a mixture thereof. The reaction is carried out in water at a temperature range of 120-300° C., with a hydrogen pressure range of 1-13 MPa. Compared with the present petroleum based synthesis technology of ethylene glycol, the method in this invention possesses advantages of using renewable feedstock, high atom economy and environmental friendly. Besides, compared with other technologies using biomass as feedstock to produce ethylene glycol, the alloy catalyst in this invention possesses the advantages of few leaching amount, good hydrothermal stability and easy to recycle.

First claim

We claim:

1. A method for catalytic conversion of carbohydrates to low-carbon diols, comprising: subjecting a carbohydrate feedstock to catalytic hydrogenation at an elevated pressure in water in the presence of an alloy catalyst,
wherein the alloy catalyst consists of tin and one or more transition metals selected from the group consisting of nickel, iron, cobalt, rhodium, ruthenium, palladium, iridium, copper, and a mixture thereof,
wherein a weight ratio between tin and the one or more transition metals is in a range of 0.01-100,
wherein the catalytic hydrogenation reaction is conducted in a reactor filled with hydrogen at a temperature higher than 120° C. for a reaction time no less than 5 minutes or at a liquid hourly space velocity of not more than 20 h −1 ,
wherein a weight concentration of the alloy catalyst in the reaction system is between 0.1 wt % and 50 wt %, and
wherein the low-carbon diol comprises ethylene glycol and 1,2-propylene glycol, wherein a yield of ethylene glycol is higher than a yield of 1,2-propylene glycol, and wherein tin in the alloy is metallic.

2. The method of claim 1 , wherein the hydrogen is filled in the reactor prior to the catalytic hydrogenation reaction, and an initial hydrogen pressure at room temperature is between 1 and 12 MPa, and the reaction temperature is lower than a thermal decomposition temperature of the low carbon diol.

3. The method of claim 1 , wherein the reaction temperature is between 200° C. and 280° C. and the initial hydrogen pressure at room temperature is between 3 and 7 MPa.

4. The method of claim 1 , wherein the alloy catalyst is a skeletal alloy catalyst composed of a nickel-tin alloy, the weight ratio between tin and nickel is in the range of 0.1-10, and the weight concentration of alloy catalyst in the reaction system is between 1 wt % and 30 wt %.

5. The method of claim 4 , wherein the weight ratio between tin and nickel in the skeleton alloy catalyst is in the range of 0.5-2; the weight concentration of alloy catalyst in the reaction system is between 2 wt % and 20 wt %.

6. The method of claim 1 , wherein the alloy catalyst is a supported catalyst, wherein metallic tin and the one or more transition metals are supported on a carrier, wherein the carrier is selected from the group consisting of activated carbon, alumina, silica, silicon carbide, zirconia, zinc oxide and titanium dioxide, and a mixture thereof, wherein a the weight concentration of alloy in the supported catalyst is between 0.01 wt % and 50 wt %, and wherein the weight ratio between tin and the one or more transition metals in the supported catalyst is in the range of 0.1-10.

7. The method of claim 6 , wherein the weight concentration of alloy in the supported catalyst is between 1 wt % and 35 wt %, and wherein the weight ratio between tin and the one or more transition metals in the supported catalyst is in the range of 0.5-2.

8. The method of claim 1 , wherein the carbohydrate feedstock comprises cellulose, starch, hemicellulose, glucose, mannose, xylose, arabinose, xylooligosaccharide, erythrose, chitosan, or a mixture thereof.

9. The method of claim 1 , wherein the reaction time is between 0.5 h and 5 h in a sealed high pressure reactor.

10. The method of claim 1 , wherein the reactor has a liquid hourly space velocity between 0.1 and 20 h −1 in a semi continuous high pressure reactor or a continuous high pressure reactor, wherein the liquid hourly space velocity is a ratio of a total dry mass of the carbohydrate feedstock into the reactor per hour to a total mass of catalyst in the reactor.

11. The method of claim 1 , wherein the alloy catalyst is converted from the precursor of the alloy catalyst in situ in the reactor, wherein the precursor of the alloy catalyst comprises a precursor of tin and a precursor of the one or more transition metals, wherein the precursor of tin is metallic tin, one or more tin compounds, or a mixture thereof, and the precursor of the one or more transition metals are selected from the group consisting of metallic and chemical compounds of nickel, iron, cobalt, rhodium, ruthenium, palladium, iridium, copper, and a mixture thereof.

12. The method of claim 11 , wherein the precursor of the one or more transition metals is supported on a carrier, and the carrier is the precursor of tin, and wherein a weight concentration of transition metals in the catalyst is between 0.01 wt % and 50 wt %.

13. The method of claim 11 , wherein the precursor of tin is supported on a carrier and the carrier is the precursor of the one or more transition metals, and the weight concentration of tin in the catalyst is between 0.01 wt % and 50 wt %.

14. The method of claim 11 , wherein the precursor of tin is metallic tin, stannous fluoride, stannous fluoride, stannous bromide, stannous iodide, stannic fluoride, stannic chloride, stannic bromide, stannic iodide, stannic hydroxide, stannous hydroxide, stannous oxide, stannic oxide, stannous mono-sulphate, stannic acetate, stannous oxalate, sodium stannate, potassium stannate, calcium stannate, tin phosphide, stannous pyrophosphate, or a mixture thereof.

15. The method of claim 11 , wherein the precursor of the one or more transition metals is metallic iron, metallic cobalt, metallic rhodium, metallic ruthenium, metallic palladium, metallic iridium, metallic copper, skeletal iron (Raney iron), skeletal cobalt (Raney cobalt), skeletal copper (Raney copper), ferric nitrate, cobalt nitrate, ruthenium nitrosyl nitrate, rhodium nitrate, palladium nitrate, iridium nitrate, copper nitrate, ferric chloride, cobalt chloride, ruthenium chloride, rhodium chloride, palladium chloride, iridium chloride, copper chloride, ferric oxide, ferroferric oxide, ferrous oxide, iron sulfate, cobalt(II) oxide, cobalt sesquioxide, cobaltosic oxide, cobaltous sulfate, nickel sulfate, copper oxide and copper sulfate, or a mixture thereof.

16. The method of claim 1 , wherein the carbohydrate feedstock is cellulose, starch, hemicellulose, xylose, and/or glucose and a yield of ethylene glycol is higher than a yield of propylene glycol.

17. A method for catalytic conversion of carbohydrates to low-carbon diols, comprising: subjecting a carbohydrate feedstock to catalytic hydrogenation at an elevated pressure in water in the presence of an alloy catalyst,
wherein the alloy catalyst is a skeletal nickel-tin catalyst, a skeletal copper-tin catalyst, or a skeletal cobalt-tin catalyst,
wherein a weight ratio between tin and the one or more transition metals is in a range of 0.01-100.
wherein the catalytic hydrogenation reaction is conducted in a reactor filled with hydrogen at a temperature higher than 120 ° C. for a reaction time no less than 5 minutes or at a liquid hourly space velocity of not more than 20 h −1 ,
wherein a weight concentration of the alloy catalyst in the reaction system is between 0.1 wt % and 50 wt %, and
wherein the low-carbon diol comprises ethylene glycol and 1,2-propylene glycol, wherein a yield of ethylene glycol is higher than a yield of 1,2-propylene glycol, and wherein tin in the alloy is metallic.

18. The method of claim 17 , wherein a total yield of ethylene glycol and 1,-propylene glycol is higher than 20%.

19. The method of claim 17 , wherein the skeletal tin-nickel catalyst is prepared by hydrothermal reaction between metallic tin and skeletal nickel.

Assignees

• Dalian Inst Chem & Physics Cas

Inventors

• Sun Ruiyan
• Zheng Mingyuan
• Zhang Tao
• Pang Jifeng
• Jiang Yu
• Wang Aiqin
• Wang Xiaodong

Classifications

• B01J25/02

  Raney nickel · CPC title

• B01J33/00

  Protection of catalysts, e.g. by coating · CPC title

• B01J23/835 Primary

  with germanium, tin or lead · CPC title

• B01J37/0236

  Drying, e.g. preparing a suspension, adding a soluble salt and drying · CPC title

• C07C29/132 Primary

  by reduction of an oxygen containing functional group · CPC title