(445b) Systematic Synthesis of Augmented Biomass-to-Liquid Fuel Processes

Liquid fuels from biomass potentially offer a sustainable option for supplying high volumetric energy density fuel for the transportation sector in a future solar energy driven economy. However, there are limits on the amount of sustainably available (SA) biomass that can be recovered annually without using additional agricultural land. Since the continued use of liquid fuel for transportation seems likely, conversion processes that maximize the liquid fuel output from the limited SA biomass resource are worthy of exploration.

Here, we present systematic synthesis of augmented biomass-to-liquid fuel processes, which maximize biomass carbon conversion to liquid fuel by using supplemental energy derived from sunlight in the form of H₂, heat, and electricity. While standalone biomass-to-liquid fuel processes are limited to <50% biomass carbon recovered as liquid fuel, augmented processes overcome this barrier by utilizing biomass as a carbon source combined with supplemental solar energy use. The emphasis is on identifying augmented processes that require the least amount of supplemental solar energy input corresponding to a given biomass carbon recovery.

 We focus on two promising biomass to liquid fuel thermochemical approaches of heat-assisted biomass gasification followed by fuel synthesis and biomass fast-hydropyrolysis/hydrodeoxygenation (HDO). A superstructure of all possible process configurations for the aforementioned thermochemical routes is developed. Subsequently, an equation-oriented nonlinear optimization model is solved to identify the optimal process configuration for different target carbon recovery levels. The novel features of the process synthesis include: 1) a simplified fast-hydropyrolysis/HDO model derived from experimental literature, 2) simultaneous process heat, power and mass integration while allowing for co-generation and 3) flexibility to design for different carbon recovery levels. The presentation will also briefly discuss the progress in developing a theoretical guarantee of the global optimality of the solutions presented.