TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Properties: The catalyst comprises particles with an average particle size of 0.2 microns-2 mm. The particulate metal oxide has a surface area of 1-200 m2/g. The catalyst has a porosity of 0.3-0.6 and a pore volume of 0-0.6 ml/g. Preferred Components: The Bronsted acid is hydrobromic acid, hydrochloric acid, hydroiodic acid, nitric acid, perchloric acid, boric acid, chloric acid, pyrophosphoric acid, chromic acid, permanganic acid, or preferably sulfuric acid or phosphoric acid. The Bronsted base is sodium hydroxide, potassium hydroxide, or lithium hydroxide.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: The reaction mixture is reacted with catalyst at 350-400degreesC and 1500-5000 psi for less than 60 seconds. Removal of residual free fatty acids from the reaction mixture includes adding dimethyl carbonate; or adsorbing free fatty acids to a metal oxide substrate and separating the reaction mixture from the metal oxide substrate. The process includes adding scent precursor compound comprising carboxylic acid group(s) before reacting the mixture with catalyst. Preferred Components: The alcohol is 1-6C alcohol. The lipid feed stock comprises triglyceride and/or carboxylic acid, and acidulated soapstock, tall oil, rapeseed oil, soybean oil, canola oil, cottonseed oil, grape seed oil, mustard seed oil, corn oil, linseed oil, sunflower oil, poppy seed oil, walnut oil, peanut oil, rice bran oil, camellia oil, castor oil, olive oil, palm kernel oil, coconut oil, rice oil, algae oil, seaweed oil, Chinese Tallow tree oil, yellow grease, choice white grease, lard, tallow, brown grease, fish oil, or poultry fat. The Bronsted acid may be methanethiol, phytic acid, or ethylenediamine tetramethyl phosphonic acid (EDTPA). Preferred Properties: The lipid feed stock has an acid number of greater than or equal to 3 mg KOH/g oil. EXAMPLE - Phosphoric acid modified zirconia particles were packed into a column which was placed in a block heater. Soybean oil (0.336 ml/minute) was pumped from a reservoir with an HPLC pump and combined with HPLC-grade methanol (0.112 ml/minute) that was pumped from a second HPLC pump with a stainless steel that was immersed in silicone oil. The silicone oil was kept at constant temperature and used to preheat the reactants at 150degreesC before they entered the phosphated zirconia column. The phosphated zirconia column was temperature controlled using a fast-response resistive heating block. Overall pressure of 750 psi was kept on the column. The reaction was conducted at 270degreesC. Sample was collected and assessed for its fatty acid methyl ester (FAME) content. Conversion was 95.3%, calculated by assuming that 95% soybean oil was triglyceride and that there was 1:1 mass ratio of triglyceride to biodiesel. There were 3 FAME molecules/1 molecule triglyceride.