Synthesis of augmented biofuel processes using solar energy

A method for synthesizing augmented biofuel processes, which improve biomass carbon conversion to liquid fuel (carbon) using supplemental solar energy as heat, H2, and electricity is presented. For a target carbon, our method identifies augmented processes requiring the least solar energy input. A nonconvex mixed integer nonlinear programming model allowing for simultaneous mass, heat, and power integration, is built over a process superstructure and solved using global optimization tools. As a case study, biomass thermochemical conversion via gasification/Fischer-Tropsch synthesis and fast-hydropyrolysis/hydrodeoxygenation (HDO) is considered. The optimal process configurations can be categorized either as standalone (carbon54%), augmented using solar heat (54%carbon74%), or augmented using solar heat and H2 (74carbon95%). Importantly, the process H2 consumption is found to be close to the derived theoretical minimum values. To accommodate for the intermittency of solar heat/H2, we suggest processes that can operate at low and high carbon. (c) 2014 American Institute of Chemical Engineers