Designing production-optimal alternative fuels for conventional, flexible-fuel, and ultra-high efficiency engines

Abstract

Road transportation needs to abandon fossil fuels. One promising alternative are renewable fuels for internal combustion engines. We consider three competing types of spark-ignition engines, i.e., conventional spark-ignition engines (CSIEs), flexible fuel vehicle engines (FFVEs), and ultra-high efficiency engines (UHEEs), which all have different fuel requirements. To determine which engine-fuel combination is optimal regarding fuel production cost and global warming impact (GWI), we apply our integrated fuel and process design method [König, et al. 2020. Comput. Chem. Eng.]. Specifically, we consider 47 pre-screened fuel species, their selective production routes from renewable resources, and a surrogate for optional blending of fossil gasoline. The designed FFVE (UHEE) fuels reduce GWI by up to 87% (84%) compared to fossil gasoline. In contrast, optimal CSIE fuels only achieve up to 60% GWI reduction and only at higher cost. The superior production performance of selectively-produced UHEE and FFVE fuels motivates replacement of today’s CSIE technology.