CHEMICAL EQUILIBRIUM STUDY OF SYSTEMS RELATED TO BIOFUELS – TEACHING EXPERIENCE WITH THERMODYNAMIC ANALYSIS OF HYDROGENATION OF VEGETABLE OILS

Total hydrogenation of vegetable oils to yield hydrocarbons is an emerging process for production of biofuels. Some researchers have been chosen tristearate as a model compound to represent vegetable oils in the calculations. The first problem is that its thermodynamic data were not available in literature, their values were estimated by using the Joback’s contribution method. Based on the comparison to  enthalpy of formation estimated in this work and in Smejkal et al., it was concluded that the chosen method can influence in the result of thermodynamic data. In this work, we realised that the basic thermodynamic analysis of the reaction system was performed presenting some misconceptions and problems which must be better discussed and checked. Calculations were done in classroom and as home-work, then the results have pointed out corrections