Method of producing coupled radical products from biomass
View Patent ↗A method that produces coupled radical products from biomass. The method involves obtaining a lipid or carboxylic acid material from the biomass. This material may be a carboxylic acid, an ester of a carboxylic acid, a triglyceride of a carboxylic acid, or a metal salt of a carboxylic acid, or any other fatty acid derivative. This lipid material or carboxylic acid material is converted into an alkali metal salt. The alkali metal salt is then used in an anolyte as part of an electrolytic cell. The electrolytic cell may include an alkali ion conducting membrane (such as a NaSICON membrane). When the cell is operated, the alkali metal salt of the carboxylic acid decarboxylates and forms radicals. Such radicals are then bonded to other radicals, thereby producing a coupled radical product such as a hydrocarbon. The produced hydrocarbon may be, for example, saturated, unsaturated, branched, or unbranched, depending upon the starting material.
1. A method for producing a coupled radical product from biomass comprising:
obtaining a quantity of biomass comprising a carboxylic acid;
converting the biomass into at least one alkali metal salt of the carboxylic acid, wherein the alkali metal comprises sodium such that the at least one alkali metal salt of the carboxylic acid comprises a sodium salt of the carboxylic acid;
preparing an anolyte, wherein the anolyte comprises a quantity of the at least one alkali metal salt of the carboxylic acid, wherein the anolyte is within an anolyte compartment of an electrolytic cell, and wherein the electrolytic cell further comprises a catholyte compartment housing a catholyte, wherein the anolyte compartment comprises an anode, the catholyte compartment comprises a cathode, and the anolyte and catholyte compartments are separated by an alkali ion conducting membrane;
adding hydrogen gas to the anolyte compartment; and
decarboxylating the at least one alkali metal salt of the carboxylic acid within the anolyte within the electrolytic cell, wherein the decarboxylating converts the at least one alkali metal salt of the carboxylic acid into alkyl radicals that react to form a coupled radical product comprising an alkyl radical coupled to a hydrogen radical;
wherein alkali metal ions are selectively transported across the alkali ion conducting membrane from the anolyte compartment to the catholyte compartment under influence of an electrical potential.
2. A method as in claim 1 , wherein the coupled radical product is a hydrocarbon.
3. A method as in claim 1 , wherein the step of converting the biomass into at least one alkali metal salt of the carboxylic acid comprises saponification, wherein a base is reacted with a quantity of the carboxylic acid to produce the at least one alkali metal salt of the carboxylic acid.
4. A method as in claim 3 , wherein the step of obtaining the biomass comprises:
extracting a lipid or lignin from the biomass; and
hydrolyzing the lipid or lignin to form the carboxylic acid.
5. A method as in claim 3 , wherein the decarboxylating occurs within the electrolytic cell, and wherein the saponification occurs within the same electrolytic cell.
6. A method as in claim 3 , wherein a reaction at the cathode in the catholyte compartment produces hydrogen gas and the base that is reacted with the quantity of the carboxylic acid to produce the at least one alkali metal salt of the carboxylic acid.
7. A method as in claim 1 , wherein the step of converting the biomass comprises reacting a base with the quantity of biomass to produce the at least one alkali metal salt of the carboxylic acid.
8. A method as in claim 1 , wherein the step of converting the biomass comprises fermentation to produce the alkali metal salt of the carboxylic acid.
9. A method as in claim 1 , wherein the step of obtaining the biomass comprises:
fermenting the biomass to produce the carboxylic acid; and wherein the step of converting the biomass comprises:
saponifying the carboxylic acid to produce the least one alkali metal salt of the carboxylic acid.
10. A method as in claim 1 , wherein the step of obtaining the biomass comprises hydrolyzing a carbohydrate in the biomass to produce the carboxylic acid.
11. A method as in claim 1 , wherein the alkali ion conducting membrane is a NaSICON membrane.
12. A method as in claim 1 , wherein a reaction at the cathode in the catholyte compartment produces hydrogen gas and a base.
13. A method as in claim 12 , wherein the step of converting the biomass into at least one alkali metal salt of the carboxylic acid comprises a saponification reaction, wherein the base produced from the catholyte is reacted with a quantity of the carboxylic acid to produce the at least one alkali metal salt of the carboxylic acid.
14. A method as in claim 12 , wherein at least one of the anode and anolyte comprises a metal chosen from palladium, rhodium, nickel, platinum, iridium, and ruthenium.
15. A method as in claim 1 , wherein the anolyte comprises a first solvent or a first mixture of solvents, and wherein the catholyte comprises a second solvent or a second mixture of solvents, wherein the first solvent or the first mixture of solvents included in the anolyte do not have to be the same as the second solvent or the second mixture of solvents included in the catholyte.
16. A method as in claim 15 , wherein the first solvent or first mixture of solvents comprises methanol.
17. A method as in claim 15 wherein the first mixture of solvents comprises at least one G-type solvent and at least one H-type solvent.
18. A method as in claim 17 , wherein the G-type solvent comprises a solvent chosen from ethylene glycol, glycerine, 1,2-dihydroxy-4-oxadodecane, 2-methyl-2-propyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 2-amino-2-methyl-1,3-propanediol, 2,3-butanediol, 3-amino-1,2-propanediol, 1,2-octanediol, cis-1,2-cyclohexanediol, trans- 1,2-cyclohexanediol, cis-1,2-cyclopentanediol, 1,2-pentanediol, and 1,2-hexanediol.
19. A method as in claim 18 , wherein the H-type solvent comprises a solvent chosen from isopropanol, methanol, ethanol, butanol, amyl alcohol, octanol, hexane, trichloroethane, dichloroethane, methylene dichloride, chloroform, carbon tetrachloride, tetralin, decalin, monoglyme, diglyme, tetraglyme, acetone, and acetaldehyde.
20. A method as in claim 18 , wherein the coupled radical product further comprises a hydrocarbon, wherein the H-type solvent comprises a fraction of the hydrocarbon product.
21. The method as in claim 15 , wherein the alkali ion conducting membrane prevents the first solvent or the first mixture of solvents and the second solvent or the second mixture of solvents from mixing.
22. A method as in claim 1 , wherein the anolyte is at a higher temperature and/or pressure than the catholyte.
23. A method as in claim 1 , wherein the at least one alkali metal salt of the carboxylic acid further comprises an alkali metal acetate.
24. A method as in claim 1 , wherein decarboxylating the anolyte forms hydrogen radicals in addition to the alkyl radicals.
25. A method as in claim 24 , wherein the hydrogen radicals are formed from an alkali metal formate.
26. A method as in claim 1 , wherein the hydrogen radicals are formed from photolysis of the hydrogen gas added to the anolyte compartment.
27. A method as in claim 1 , wherein decarboxylating the at least one alkali metal salt of the carboxylic acid comprises photolysis.
28. A method as in claim 1 , wherein the at least one alkali metal salt of the carboxylic acid is derived from a monocarboxylic acid, a dicarboxylic acid, or a polycarboxylic acid.
29. A method as in claim 1 , wherein the biomass further comprises carbohydrates, esters of carboxylic acids, triglycerides, lipids, oils, phospholipids, carboxylic acid derivatives, lignins, tall oil, resins, switch grass, algae, and/or metal salts of carboxylic acids.
30. A method as in claim 1 , wherein the biomass further comprises an animal, a plant, and/or a microbial.