Method of producing coupled radical products
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 comprising:
preparing an anolyte for use in an electrolytic cell, the electrolytic cell comprising an alkali ion conducting membrane, wherein the membrane divides the cell into an anolyte compartment and a catholyte compartment, the anolyte being housed within the anolyte compartment and a catholyte being housed within the catholyte compartment, wherein the anolyte comprises a first solvent or mixture of first solvents and a quantity of an alkali metal salt of a carboxylic acid and an alkali metal salt of a low-carbon carboxylic acid, wherein the catholyte compartment comprises a second solvent or mixture of second solvents, wherein the alkali ion conducting membrane prevents the first solvent and the second solvent from mixing;
electrochemical decarboxylating the alkali metal salt of the carboxylic acid of the anolyte within the electrolytic cell, wherein the electrochemical decarboxylating converts the alkali metal salt of the carboxylic acid into alkyl radicals that react to form a coupled radical product, wherein at least some alkyl radicals couple to radicals or formed by electrochemical decarboxylating of said alkali metal salt of the low-carbon carboxylic acid, wherein alkali metal ions are selectively transported across the alkali ion conducting membrane from the anolyte compartment to the catholyte compartment under influence of a electrical potential, wherein an electrochemical reaction of the catholyte produces an alkali metal base in the catholyte compartment; and
using the alkali metal base produced in the catholyte compartment to prepare the alkali metal salt of the carboxylic acid.
2. A method as in claim 1 , wherein the coupled radical product comprises a hydrocarbon.
3. A method as in claim 1 , wherein the alkali metal comprises sodium such that the alkali metal salt of the carboxylic acid comprises a sodium salt of the carboxylic acid and wherein the alkali ion conducting membrane comprises a NaSICON membrane.
4. A method as in claim 1 , wherein the first solvent comprises a two-phase solvent system, wherein one phase is capable of dissolving ionic materials and the other phase is capable of dissolving non-ionic materials.
5. A method as in claim 1 , wherein the first solvent or the mixture of first solvents comprises methanol.
6. A method as in claim 1 , wherein the second solvent or the mixture of second solvents included in the catholyte and the first solvent or the mixture of first solvents included in the anolyte are different.
7. A method as in claim 6 , wherein the first solvent or the mixture of first solvents comprises an organic solvent and the second solvent or the mixture of second solvents comprises an inorganic solvent.
8. A method as in claim 1 , wherein the alkali metal salt of the low-carbon carboxylic acid comprises an alkali metal formate.
9. A method as in claim 1 , wherein the alkali metal salt of the carboxylic acid is formed via a saponification reaction that occurs within the electrolytic cell.
10. A method as in claim 9 , wherein the alkali metal salt of the carboxylic acid is formed via a saponification reaction that occurs within the catholyte compartment.
11. A method as in claim 10 , further comprising:
adding a carboxylic acid to the catholyte compartment;
saponifying the carboxylic acid to form the alkali metal salt of the carboxylic acid; and
introducing the alkali metal salt of the carboxylic acid into the anolyte compartment.