Exergy Evaluation of Biodiesel Production Process from Euphorbia Lathyris

At present, studies on the various sources of biodiesel are quite noticeable, due to the reduction of emissions of air pollutants. Research on the advantages and disadvantages of biodiesel establish that higher cetane number, improves the combustion process allowing increasing the compression ratio of the engine. Less sulfur content is safer to store and transport. However, when compared to conventional fuels, it presents costlier production process which also depends on the type of selected raw material. On this basis, research has been conducted to find the best raw materials and suitable for the production of biodiesel from non-edible sources. In this regard spurge (Euphorbia lathyris) is considered here which is characterized by being a plant of easy culture, can be grown in different environments and is not source human food. Therefore, it is a promising feedstock for biofuels industry, specifically for the production of biodiesel. The viability of the process was evaluated with exergy analysis, a useful tool to identify the losses energy using the first and second law of the thermodynamics. This tool also evaluates and proposes improvements for emerging technologies. Simulation of biodiesel production process using E. lathyris oil through transesterification with alkaline catalysis in Aspen PlusTM software was performed. Comparing E. lathyris with other raw materials was used for the same purpose. It also have a low free fatty acids (FFA) (0.2 %) content that represents a great benefit in the production of biodiesel because of the esterification process is not necessary. This advantage is reflected in a cost savings due to the reduction of equipment used in the process. The enthalpy, entropy and Gibbs free energy was calculated with help of the software. Finally, for all streams the chemical and physical exergy was calculated and later the efficiency exergetic of the process is estimated. The exergy efficiency of the process (57 %) confirms the potential of this raw material for production of Biodiesel. However more improvements are necessary to increase the energy production of the process.