Implementation of Heat Integration to Improve the Sustainability of an Integrated Biodiesel Biorefinery

Abstract

Recently, a great research effort has been dedicated in order to establish integrated biorefineries as the next generation plants for the production of fuels, energy and chemicals. In this work, heat integration techniques are applied to an integrated biodiesel biorefinery that as well as biodiesel it also produces succinic acid through a fermentation process in order to improve its economic efficiency. Initially, heat integration options are identified by extracting the thermodynamic results of the overall biorefinery from simulations carried out in Aspen Plus 2006.5. By implementing pinch analysis and stochastic optimisation techniques, we determine a new heat exchanger network (HEN) that shows a minimum total annualised cost (TAC) of the overall HEN. The optimisation of the HEN results in a 17.2 % reduction in the TAC and 62.3 % and 64.2 % reduction in the hot and cold utilities, respectively, compared to the initial plant.