Alternatives to petroleum-based fuels must be commercialized to ensure national energy security, but profitable, clean, carbon-neutral energy sources have proven difficult to develop. Biodiesel is one alternative that is attractive: it is renewable and carbon-neutral and can be manufactured from a broad variety of domestic feedstocks. Both triglycerides (oils) and free fatty acids (FFAs) can be reacted with alcohol to form fatty acid methyl esters (FAME, aka biodiesel).
This study explores reaction kinetics of triglycerides/FFAs and methanol to biodiesel using solid metal and metal oxide catalysts in batch reactors and in continuous flow microchannels. FFA’s are successfully converted to biodiesel significantly faster than triglycerides. FFA’s can also act as a co-solvent between the immiscible triglycerides and alcohol. The effects of feed fractions (triglycerides/FFAs/methanol), multiple liquid phases, and temperature on kinetics are investigated. The impact of these effects on the design and operation of microreactors will be discussed.