Multi-objective optimization methodology for process synthesis and intensification: Gasification-based biomass conversion into transportation fuels

The transport sector increasing energy demand has encouraged the search for alternative technologies for biofuels production with lower manufacturing costs and higher process efficiency and environmental performance. Lignocellulosic biofuels are equivalents to petroleum products and can be adapted to meet the properties requirements of current engines. However, their major disadvantages are the high production costs and the lack of infrastructure. In this work, the focus is on the implementation of a multi-objective optimization methodology for synthesis of novel intensified biomass-to-liquid (BtL) technologies with lower environmental impact and costs, as well as higher process safety and efficiency. A novel optimization methodology is applied to two process configurations that were synthesized in a previous work [1], in which the evaluation of a BtL processing superstructure under different economic constraints and product profiles scenarios was performed. From the configurations, the two case studies with higher production of both gasoline and diesel were selected for this work. For the synthesis of intensified BtL technologies, the optimal separation units’ design parameters that meet the combination of economic, safety and environmental indexes, and two green chemistry metrics were selected. By applying the methodology, the optimal intensified process presents a higher return on investment of 22 (%/y) compared to 18 (%/y) for the base case flowsheet.