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.