Morais, Sérgio AlbertoMata, Teresa M.Martins, A. A.Pinto, GilbertoCosta, Carlos A.V.2013-11-292013-11-29201010.1016/j.jclepro.2010.04.0140959-6526http://hdl.handle.net/10400.22/3030This study uses the process simulator ASPEN Plus and Life Cycle Assessment (LCA) to compare three process design alternatives for biodiesel production from waste vegetable oils that are: the conventional alkali-catalyzed process including a free fatty acids (FFAs) pre-treatment, the acid-catalyzed process, and the supercritical methanol process using propane as co-solvent. Results show that the supercritical methanol process using propane as co-solvent is the most environmentally favorable alternative. Its smaller steam consumption in comparison with the other process design alternatives leads to a lower contribution to the potential environmental impacts (PEI’s). The acid-catalyzed process generally shows the highest PEI’s, in particular due to the high energy requirements associated with methanol recovery operations.engBiodieselWaste vegetable oilProcess designProcess simulationLife cycle assessment (LCA)Alkali-catalyzed processAcid-catalyzed processSupercritical methanol processjournal article