Graphical exergy analysis of reactive distillation column for biodiesel production

This paper brings the novelty of the exergy analysis technique using Ex–N–A diagram to a packed reactive distillation (RD) column for biodiesel production. In this study, biodiesel is produced through the esterification of fatty acid with methanol. The simulation of the column was performed based on the non–equilibrium (NEQ) model of a three–phase packed RD system. The graphical Ex–N–A method was utilised to evaluate exergy features of the internal RD column. This technique rigorously demonstrated the value of exergy losses at each increment of the column, i.e., losses owing to the temperature change, phase change, mixing in liquid and vapour phases and chemical reaction. The effects of the molar ratio of the reactant and the height of the packed column on the conversion and exergy losses were examined and displayed in a simple figure.

Keywords: exergy analysis, reactive distillation column, esterification, Ex–N–A diagram, biodiesel production, biofuels, fatty acids, methanol, simulation, non–equilibrium model, modelling, exergy losses, temperature change, phase change, mixing, chemical reaction, molar ratio, reactants, packed column height