Biodiesel production by the methylic-alkaline and ethylic-enzymatic routes: Discussion of some environmental aspects

A comparative environmental impact analysis of the soybean biodiesel production by two different technologies is run in this study. The production routes evaluated were the alkali-catalyzed (catalyst: sodium hydroxide) methylic transesterification and enzyme-catalyzed (catalyst: lipase) ethylic transesterification. The study includes the simulation of the biodiesel production process with the software Aspen HYSYS, from AspenTech Inc., and a subsequent comparative analysis of the main environmental impacts observed in each case, based on the application of two approaches: analysis of the Principles of Green Chemistry and calculation of some sustainability metrics. Results indicated a better environmental performance for the enzymatic route, in almost all the analyzed issues, what proves that this route is an excellent option for future industrial applications, regarding safety and sustainability. (C) 2017 Elsevier Ltd. All rights reserved.