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

[Display omitted] • Model-based fuel design for conventional, flex fuel, ultra-high efficiency SI engines. • Production cost and GWI of optimized, selectively produced fuels. • Promising 100% biofuel with low GWI/low cost for ultra-high efficiency engine. • Fuels for ultra-high efficiency and flex fuel engines show better cost/GWI trade-off. • Results motivate replacing today's conventional SI engines with advanced ones. 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. [ABSTRACT FROM AUTHOR]