TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: Fermenting biomass comprises anaerobic fermentation with a mixed culture of microorganisms in a fermentation vessel or a system of vessels. The second product stream results from intermediate processing of the first product stream, and the second product stream comprises carboxylic acid salts. The intermediate processing of the first product stream comprises at least one of screening, clarifying, dewatering, purifying, concentrating with membranes, electrodialysis, electrodeionization or with evaporators, softening, degasifying, stripping, or ion exchange. Concentrating with membranes occurs at the same, about the same or higher pressure than the acidification with high-pressure carbon dioxide while performing liquid-liquid extraction. Acidifying comprises using an electrochemical acidification unit (EAU) (202) or using ion exchange with high-pressure carbon dioxide regeneration or using high-pressure carbon dioxide while performing liquid-liquid extraction. Processing the fourth product stream comprises fractionating the acids or converting at least a portion of the acids to ketones or to ethyl acetate. Using an EAU results in production of a hydroxide stream, where at least some of the hydroxide stream is recycled for use in the fermenting step; or the regeneration of the ion exchange beds with high-pressure carbon dioxide results in the production of a carbonate or bicarbonate stream, where at least some of the carbonate or bicarbonate stream is recycled for use in the fermenting step; or the acidification with high-pressure carbon dioxide while performing liquid-liquid extraction results in the production of a carbonate or bicarbonate stream, where at least some of the carbonate or bicarbonate stream is recycled for use in the fermenting step. The EAU is operably configured with electrodialysis with bi-polar membranes (EDBM) with at least two stages or operably configured with an alkalinity based on low energy system with at least two stages. The carbon dioxide for regenerating the ion exchange beds or for the acidification with high-pressure carbon dioxide while performing liquid-liquid extraction is mostly obtained from the carbon dioxide generated in the fermentation. At least a portion of the aqueous phase in the third product is recycled to the fermentation where the aqueous phase in the third product comprises short-chain fatty acids or salts. Preferred Components: The carboxylic acid salts further comprise volatile fatty acid (VFA) salts or short- and medium-chain fatty acid salts. EXAMPLE - 200 ml Solution containing volatile fatty acid sodium salts with the acid profile of 2C (acetic) to 8C (octanoic acids) as it would be produced in fermentation, were mixed with 100 ml octanoic acid under 1000 psi of carbon dioxide pressure at 25 degrees C. The system was allowed to reach equilibrium to allow the acids to be extracted by the octanoic acid and then the aqueous and organic phases were allow to settle and separate without releasing the pressure. A sample of the aqueous phase was taken analyzed using a gas chromatogram with a flame-ionization detector to provide 9.4% acetic acid, 38.8% propionic acid, 74% isobutyric acid, 67.7% butyric acid, 87.3% isovaleric acid, 88.5% valeric acid, 96.3% caproic acid and 98.8% heptanoic acid.