Progress in the Use of Biobutanol Blends in Diesel Engines

Abstract

Nowadays, the transport sector is trying to face climate change and to contribute to a sustainable world by introducing modern after-treatment systems or by using biofuels. In sectors such as road freight transportation, agricultural or cogeneration in which the electrification is not considered feasible with the current infrastructure, renewable options for diesel engines such as alcohols produced from waste or lignocellulosic materials with advanced production techniques show a significant potential to reduce the life-cycle greenhouse emissions with respect to diesel fuel. This study concludes that lignocellulosic biobutanol can achieve 60% lower greenhouse gas emissions than diesel fuel. Butanol-diesel blends, with up to 40% butanol content, could be successfully used in a diesel engine calibrated for 100% diesel fuel without any additional engine modification nor electronic control unit recalibration at a warm ambient temperature. When n-butanol is introduced, particulate matter emissions are sharply reduced for butanol contents up to 16% (by volume), whereas NOX emissions are not negatively affected. Butanol-diesel blends could be introduced without startability problems up to 13% (by volume) butanol content at a cold ambient temperature. Therefore, biobutanol can be considered as an interesting option to be blended with diesel fuel, contributing to the decarbonization of these sectors.