The process for preparing a refinery feedstock from black liquor soap comprising adding excess alcohol (preferably methanol) to black liquor soap. Acid is then added to the mixture to drop the pH of the mixture to approximately 2 to convert carboxylate salt of fatty and resin acids to the free fatty and resin acids. In the reaction process, the free fatty and resin acids react with the alcohol, with the aid of the acid catalyst, to yield the desired ester products. The resulting feedstock can be distilled or refined to yield sterols and related alcohols, biodiesel and other fuels.