Comprehensive analysis and process simulation of biodiesel production from biomass sources

Abstract

The present research work entails the process simulation of biodiesel production on a large scale using the ASPEN process simulator. Catalytic transesterification and non-catalytic supercritical mode of transesterification are simulated with experimental results and compared to determine the efficient mode of transesterification under different initial feedstock raw material conditions. It is found that the supercritical method (280℃; 276.4 atm; 42:1 for alcohol and oil ratio) is efficient in terms of cost and product quality for the feedstocks with high Free Fatty Acid (FFA) content. For feedstocks with a negligible amount of FFA, alkali-catalyzed homogeneous transesterification (60-65℃; 4atm; 6:1- alcohol: oil ratio) is efficient in terms of product quality and yield although the cost is similar to that of the supercritical mode of transesterification. Pre-treatment steps like simple esterification and glycerolysis for high FFA-contained feedstocks are studied using the ASPEN simulation to understand better the overall process by which the pre-treatment is carried out. Finally, the combustion characteristics of the biodiesel blend along with n-heptane (a surrogate for Petro-diesel) are studied using the Python scripted Cantera combustion chamber and it is found that the amount of soot and carbon monoxide emission is very less indicating complete and efficient combustion. This simulation study is carried out with the help of DWSIM simulation software.