Oils from plants and animal fats are hydrolyzed to fatty acids for a Kolbe reaction. The invention relates to a high productivity Kolbe reaction process for electrochemically decarboxylating C4-C28 fatty acids using small amounts of acetic acid to lower anodic passivation voltage and synthesizing C6-C54 hydrocarbons. The C6-C54 undergo olefin metathesis and/or hydroisomerization reaction process to synthesize heavy fuel oil, diesel fuel, kerosene fuel, lubricant base oil, and linear alpha olefin products useful as precursors for polymers, detergents, and other fine chemicals.