TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The process further involves e) recovering the biofuel; concentrating ester before either hydrogenolysis or hydrogenation; and separating insoluble compounds by filtering before either hydrogenolysis or hydrogenation. The fermentation broth is part of a continuous fermentation process, and the process further involves recycling the insoluble compounds back into fermentation broth. The fermentation broth contains cell mass and insoluble compounds and the process further involves filtering the cell mass and insoluble compounds from fermentation broth either before drying or after ester synthesis. The fermentation broth is part of a batch fermentation process, and the process further involves recycling the insoluble compounds into a second fermentation reactor. The reaction temperature is 150-250 degrees C, and the pressure is 400-3000 psi. The free carboxylic acids are not subject to activation with a halide to form an acyl halide. The fermentation broth is at a pH of less than 5 (preferably 1.5-4.5). The drying is by at least one of the following: spray drying, drum drying, or cryodesiccation. The mixture of free carboxylic acids contains at least a diacid, triacid, or polyacid, and reaction with alcohol yields a minimum of 50% conversion of diacid, triacid, or polyacid to a corresponding ester of the free carboxylic acid. The process further involves purifying ester to at least 90% purity, where the purifying is by at least one of the following: crystallization, chromatography, or distillation. Preferred Components: The alcohol solvent has R-group of 1-25C, and is at least one saturated, unsaturated, cyclic, or aromatic species. The carboxylic acid is selected from: formic acid, acetic acid, propionic acid, lactic acid, butyric acid, isobutyric acid, valeric acid, hexanoic acid, heptanoic acid, decanoic acid, lauric acid, myristic acid, and 15-18C fatty acids, fumaric acid, itaconic acid, malic acid, succinic acid, maleic acid, malonic acid, glutaric acid, glucaric acid, oxalic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, glutaconic acid, ortho-phthalic acid, isophthalic acid, terephthalic acid, citric acid, isocitric acid, aconitic acid, tricarballylic acid, and tri mesic acid. The carboxylic acid is polycarboxylic acid. The polycarboxylic acid is a dicarboxylic or a tricarboxylic acid; and ester is at least a diester. EXAMPLE - No suitable example given.