Decarboxylative co-dimerization process and synthetic fuels produced therefrom
In an aspect, the application discloses a method for producing renewable hydrocarbon fuels where the method includes electrolysis of a mixture to produce an electrolysis product comprising a renewable diesel and optionally a renewable gasoline, where the mixture includes (i) free fatty acids from a biorenewable feedstock, and (ii) terminal monomethyl-branched carboxylic acids, and where the renewable diesel includes terminal monomethyl-branched paraffins and terminal monomethyl-branched alkenes.
1 . A method for producing renewable hydrocarbon fuels, the method comprising
electrolysis of a mixture in an electrolysis cell, the electrolysis cell comprising an anode and a cathode, and the mixture comprising
(i) free fatty acids distilled from fats, oils, and/or greases, and
(ii) terminal monomethyl-branched carboxylic acids in at least a 100% molar excess relative to the free fatty acids, to produce an electrolysis product comprising a renewable diesel and optionally a renewable gasoline, wherein the electrolysis comprises an electrode current density of about 0.05 A/cm 2 to about 1.0 A/cm 2 , and a cell voltage of about 8 Volts to about 35 Volts;
wherein the renewable diesel comprises terminal monomethyl-branched paraffins and terminal monomethyl-branched cis alkenes; and
wherein the renewable diesel has cloud point less than −10° C. and the cetane number greater than 60.
2 . The method of claim 1 , wherein the terminal monomethyl-branched carboxylic acids comprise isobutyric acid.
3 . The method of claim 2 , wherein the isobutyric acid is produced from isobutanol, wherein the isobutanol is from a biorenewable feedstock.
4 . The method of claim 3 , wherein the isobutyric acid is produced from isobutanol by
dehydrogenating the isobutanol to produce isobutyraldehyde and H 2 , and
oxidizing the isobutyraldehyde to produce the isobutyric acid.
5 . The method of claim 4 , wherein the H 2 produced from dehydrogenating the isobutanol is separated from the isobutyraldehyde.
6 . The method of claim 4 , wherein the H 2 from dehydrogenating the isobutanol is used in a hydrogenation reaction.
7 . The method of claim 1 , wherein the renewable gasoline comprises 2,3-dimethylbutane.
8 . The method of claim 1 , wherein the free fatty acids distilled from fats, oils, and/or greases comprise fatty acids produced from hydrolysis of fatty acid esters of fat, oil, and/or grease.
9 . The method of claim 1 , wherein the free fatty acids distilled from fats, oils, and/or greases comprise fatty acids from tall oil and/or produced from the hydrolysis of tall oil esters.
10 . The method of claim 1 , wherein the free fatty acids distilled from fats, oils, and/or greases comprise fatty acids from palm fatty acid distillate.
11 . The method of claim 1 , wherein the free fatty acids distilled from fats, oils, and/or greases comprise fatty acids distilled from palm sludge oil and/or used cooking oil.
12 . The method of claim 1 , wherein the electrolysis is powered by renewable energy.
13 . The method of claim 1 , wherein the terminal monomethyl-branched alkenes comprise at least one of (Z)-18-methylnonadec-9-ene or (6Z,9Z)-18-methylnonadeca-6,9-diene.
14 . The method of claim 1 , wherein the electrolysis does not comprise a hydroprocessing catalyst.
15 . The method of claim 1 , wherein the mixture consists essentially of
(i) free fatty acids distilled from fats, oils, and/or greases, and
(ii) terminal monomethyl-branched carboxylic acids in at least a 100% molar excess relative to the free fatty acids.
16 . The method of claim 1 , wherein the mixture consists essentially of
(i) free fatty acids distilled from fats, oils, and/or greases, where the fats, oils, and/or greases have not been hydroprocessed, and
(ii) terminal monomethyl-branched carboxylic acids in at least a 100% molar excess relative to the free fatty acids.
17 . The method of claim 1 , wherein the mixture comprises at least a 300% molar excess of the terminal monomethyl-branched carboxylic acids relative to the free fatty acids.
18 . The method of claim 15 , wherein the mixture comprises at least a 300% molar excess of the terminal monomethyl-branched carboxylic acids relative to the free fatty acids.
19 . The method of claim 16 , wherein the mixture comprises at least a 300% molar excess of the terminal monomethyl-branched carboxylic acids relative to the free fatty acids.
20 . The method of claim 1 , wherein the electrolysis comprises an electrode current density of about 0.3 A/cm 2 to about 1.0 A/cm 2 .