Feasibility of energy integration for high-pressure biofuels production processes

The production of renewable fuels has been proposed as a feasible alternative, in the shor-and medium -term, to mitigate the environmental impact due to the use of fossil fuels for the transport sector. Biodiesel and biojet fuel are promising fuels to partially replace their corresponding fossil fuels. To produce biodiesel, processes with supercritical alcohols shows some advantages over the traditional base-catalyzed processes, e.g., no undesired reactions occur when the raw material has high concentration of free fatty acids. It is worth to mention that this process operates at high pressure and temperature, so the energy demand is elevated. On the other hand, the biojet fuel production through the hydrotreatment process has been developed as a feasible alternative, due to its similarity with the conventional refining processes. Like the supercritical process for biodiesel production, bio-jet fuel production requires high pressure and temperature, thus having high energy requirement. In both processes, distillation, an energy-intensive separation process, is used to generate the desired hydrocarbons fractions. Thus, to determine potential reduction in the total energy requirements for both processes, the feasibility of energy integration between the supercritical biodiesel process and the hydrotreating process to produce bio-jet fuel is studied in this work. By this approach, reductions on the utilities costs are expected if compared with the individual processes. Also, due to energy integration, which reduces the external energy requirements, global environmental impact is expected to be reduced as well.