(579c) A Parametric Study for the Conversion of High Free Fatty Acid Lipid Feedstocks to Biofuel Using Triazabicyclodecene Catalyst

A Parametric Study for the Conversion of High Free Fatty Acid Lipid Feedstocks to Biofuel Using Triazabicyclodecene Catalyst

Obakore Agbroko, Joshua Borton, Keyvan Mollaeian, Tracy J Benson

As the world’s energy consumption is rapidly increasing many efforts are being made to produce renewable and sustainable fuel sources that provide independence, or at least displacement, from fossil fuels. Many of these renewable sources include sunlight, wind energy, geothermal energy, and the conversion of plant based biomass into biofuels. The conversion of vegetable oils into biodiesel is a highly viable option for supplementing fossil fuel energy. Unfortunately, most biodiesel is produced from oils stemming from row-crops, which take up viable land resources needed for food crops. One promising alternative is microbially-produced oils (MPOs) where microorganisms feed on industrial and municipal wastewaters. MPOs, however, contain high concentrations of free fatty acids (FFAs), unlike most row-crops. Under conventional biodiesel processes, high concentrations of FFAs in oil feedstocks significantly complicate conversion and separation of the fuel produced.
In this study, used vegetable oils which contain high FFA concentrations (4.5 – 14.5 wt%) were used to evaluate the ability of Triazabicyclodecene to function in the acidic environment. Dimethyl carbonate was used as a substitute for methanol in the transesterification and esterification reactions. Although increasing amounts of FFAs reduced the conversion of triglycerides (TGs), the TBD/DMC process was able to successfully esterify FFAs at lower temperatures and pressures than conventional industrial FFA esterification processes. This dual This dual functionality shows that the TBD/DMC process is an effective and economically competitive replacement for traditional higher energy processes.  Where glycerol free biodiesel production is required, a two-step process can still be implemented using TBD to esterify FFAs at low energy, followed by the transesterification of triglycerides without the production of glycerol.