(648a) Economical Comparison of Different Technologies for Biodiesel Production

Biodiesel is a sustainable and renewable source of energy that can be produced from vegetable oils or animal fats. Despite the growing competitiveness of this fuel due to the rising cost of petroleum-based fuels, high production costs continue to be important. More than 60% of the biodiesel production cost is associated with the raw material costs and therefore, alternative feedstocks such as waste oils, low grade oils and acid oils have been employed increasingly. The amount of free fatty acid in an acid oil could vary from 3 to 40% and higher in some cases. The problem is that the presence of free fatty acid with a base catalyst can cause the production of soaps. This significantly lowers the reaction yield and causes serious problems for the downstream separation of the products. In a sense, this renders the conventional base-catalyzed biodiesel production technology unsuitable. Thus, several alternative processes have been developed to handle this issue. In this work, several alternatives to produce biodiesel (basic transesterification with acid pre-esterification, acid transesterification, heterogeneous transesterification with resins or enzymes, supercritical processes, and membrane technology) have been studied and compared. A techno-economic analysis and comparison of these alternatives was completed using a process simulator. With these models, we were able to evaluate productivity, energy consumption and the economic competitiveness of each process.