Mass and energy integration for the supercritical process for biodiesel production and a bioethanol dehydration train

Biofuels have taken importance on the last years, due to the concern on the environmental impact of the transport sector. One of the most known liquid biofuels is biodiesel. The use of supercritical alcohols to produce biodiesel has been studied recently because of its advantages over the methods with homogeneous catalysts. Nevertheless, due to the high pressure and temperature conditions under which the supercritical process operates, the energy demand is considerable high. In addition, glycerol is produced as by-product, and it is expected that the price of glycerol falls; because of its high production on the biodiesel processes reducing the incomes for its commercialization. On the other hand, bioethanol is other well-known biofuel. To overcome the azeotrope between water and ethanol and produce high-purity bioethanol, extractive distillation is usually employed, where glycerol may be used as entrainer. Therefore, in this work it is proposed the mass and energy integration between supercritical biodiesel production process and bioethanol purification train. For the energy integration, a pinch analysis will be used to integrate the two processes, aiming to reduce the external energy demand by using the energy released by the chemical reactions. By this approach, reductions on the total annual costs can be obtained if compared with the individual processes. Also, since the energetic requirements are partially satisfied by the energy delivered in the processes, global environmental impact is reduced as well.