Comparison of feedstocks and technologies for biodiesel production: An environmental and techno-economic evaluation

Due to their high productivity in both crops and algae, tropical countries are likely to be the future world suppliers of feedstocks as well as biofuels such as biodiesel. In this work five feedstocks: palm, jatropha, microalgae, tallow and waste cooking oil were analyzed and compared using techno-economic and environmental criteria. For each feedstock, technological configurations currently used in the industry were taken into account (acid catalysis, basic catalysis and cogeneration). In this work, it was found that productivities for the basic catalyzed process were comparatively higher (1.010 kg biodiesel/kg crude oil), than those catalyzed by acid (0.85-0.95 kg biodiesel/kg crude oil). After the simulation of the selected processes, the lowest production costs were obtained for jatropha (USD 0.15/L, basic catalysis) and for waste cooking oils (USD 0.23/L, acid catalysis). The PEI (Potential Environmental Impact) generated for basic catalyzed process ranged from −0.04 to −0.09, while the acid catalyzed case −0.020 and −0.06 PEI per kg of product. The jatropha and microalgae oil using basic catalyzed configuration with energy cogeneration were the best process alternative from the environmental and economical points of view.