TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Process: Feedstock conversion further includes maintaining a pressure at or greater than an autogenous pressure (preferably at 10-100 psig above the autogenous pressure), and emulsifying the reactant mixture with a second catalyst. Performing transesterification includes combining the reactant mixture with the second catalyst comprising one of an alkaline catalyst and the acid catalyst. Applying RF or microwave energy includes modulating the energy. The modulating step includes one of amplitude modulation, frequency modulation, and/or pulse width modulation. Triglyceride conversion may comprise mixing the triglyceride with the alcohol to produce the reactant mixture; emulsifying the reactant mixture with the homogeneous catalyst; applying RF or microwave energy to one of the triglyceride, the alcohol and/or the catalyst; and producing the alkyl ester and the glycerol. Carboxylic acid conversion may comprise mixing the carboxylic acid with the alcohol to produce the reactant mixture, flowing the reactant mixture over the heterogeneous acid catalyst with a relative velocity of greater than or equal to 0.005 m/second to obtain high reactant shear at a reactant-catalyst interface, and producing the alkyl ester; or mixing the carboxylic acid with the alcohol to produce the reactant mixture, emulsifying the reactant mixture with the homogeneous acid catalyst, applying RF or microwave energy to one of the carboxylic acid, the alcohol and/or the catalyst, and producing the alkyl ester. Mixing occurs before flowing, or occurs at the same time as flowing. It includes combining the triglyceride and the alcohol in a ratio of greater than or equal to 10 wt.%, and combining the carboxylic acid and the alcohol in a ratio of greater than or equal to 11 wt.%. Triglyceride and carboxylic acid conversion further comprise maintaining the pressure at or greater than the autogenous pressure; and applying the RF or microwave energy to one of the triglyceride, the alcohol and/or the catalyst. It takes place at a pressure of 10-100 psig above the autogenous pressure. Applying the RF or microwave energy also includes controlling one of a frequency, power density, and/or field strength of the RF or microwave energy to control the reaction between the catalyst and the reactants; and modulating the energy. The average power density is maintained at 0.01-100, preferably 0.05-10 or 0.1-3 watts/cc.Preferred Parameters: The RF or microwave energy comprises a frequency of 400 MHz to 5 GHz. A relative velocity between the reactant mixture and the catalyst is greater than or equal to 0.005, preferably greater than or equal to 0.01 or greater than or equal to 0.05 m/second.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Component: The acid catalyst comprises one of a zeolite in an acid form, a strong cation exchange resin in a hydrogen form, and/or a Lewis acid. The second catalyst comprises one of a hydroxide of Group 1 or 2 metals, a silicate of Group 1 or 2 metals, a carbonate of Group 1 or 2 metals, a strong anion exchange resin in the hydroxide form, an oxide of aluminum and magnesium, zeolite in the acid form, a strong cation exchange resin in the hydrogen form, and/or the Lewis acid. It is the heterogeneous catalyst or a homogeneous catalyst. The heterogeneous catalyst comprises one of the alkaline catalyst and the acid catalyst; one of a hydroxide of Group 1 or 2 metals, a silicate of Group 1 or 2 metals, a carbonate of Group 1 or 2 metals, a strong anion exchange resin in the hydroxide form, and/or an oxide of aluminum and magnesium; or one of a zeolite in the acid form, a strong cation exchange resin in the hydrogen form, and/or a Lewis acid.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The carboxylic acid comprises a free fatty acid derived from one of tall oil, rendered oils, animal fats, and soap stock. The alcohol comprises 1-6C alcohol, preferably one of methanol and ethanol. The triglyceride and the carboxylic acid are present in one of plant oil and/or animal oil. They are present in an oil derived from one of soybeans, corn, sunflower, palm, nut, safflower, olives, cotton, linseed, mustard seed, rapeseed, canola, peanuts, coconut, castor beans, tall oil, soapstock, raw or rendered animal fats, brown grease, white grease, yellow grease, lard or tallow from pork, chicken, mutton, beef or horse, as well as wastes, and/or effluents and residues from the processing of such materials.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The acid catalyst comprises one of a zeolite in an acid form, a strong cation exchange resin in a hydrogen form, and/or a Lewis acid. The second catalyst comprises one of a hydroxide of Group 1 or 2 metals, a silicate of Group 1 or 2 metals, a carbonate of Group 1 or 2 metals, a strong anion exchange resin in the hydroxide form, an oxide of aluminum and magnesium, zeolite in the acid form, a strong cation exchange resin in the hydrogen form, and/or the Lewis acid. It is the heterogeneous catalyst or a homogeneous catalyst. The heterogeneous catalyst comprises one of the alkaline catalyst and the acid catalyst; one of a hydroxide of Group 1 or 2 metals, a silicate of Group 1 or 2 metals, a carbonate of Group 1 or 2 metals, a strong anion exchange resin in the hydroxide form, and/or an oxide of aluminum and magnesium; or one of a zeolite in the acid form, a strong cation exchange resin in the hydrogen form, and/or a Lewis acid.