Study of an Innovative Process for the Production of Biofuels using Non-edible Vegetable Oils

Abstract

In recent years, several strategies have been used to mitigate the impact of greenhouse gases, one of which is the production of liquid biofuels, where different processes have been employed such as pyrolysis, transesterification, and more recently the process of catalytic hydrotreatment. The latter was adopted to obtain a biofuel with better properties: higher heating value, lower density and better flow properties in cold than biodiesel. However also the catalytic hydrotreatment presents significant disadvantages: the use of hydrogen and the use of conventional catalysts composed of metal sulphides. On the basis of these considerations, our group is studying the deoxygenation of triglycerides through the innovative process of decarboxylation, in which the atoms of oxygen contained in the biomass are removed in the form of carbon dioxide which can then be captured. The decarboxylation process does not require the use of expensive reagents such as hydrogen or noble metal catalysts. For this work we selected the Jatropha Curcas oil as a model of non-edible oil. After our tests was possible to obtain a liquid biofuel with a high composition of hydrocarbons, around 81 %, formed mainly of C8-C15 hydrocarbons. This product also showed good properties as an heating value around 44 MJ/Kg, higher than biodiesel (39 MJ/Kg) and diesel (43 MJ/Kg), and a lower viscosity (4.2 cSt) compared to the biodiesel (4.4 cSt). The yields obtained for the overall process were greater than 80 %.