Biogasoline options for conventional spark-ignition cars

The purpose of this study is to explore feasible gasoline biocomponents supplementary to ethanol, and to assess their exhaust emissions performance. Although ethanol is the dominant liquid biofuel globally, technical restrictions limit its use in conventional gasoline cars to 10-15 v/v% (bio-energy 7-10%). Since current conventional cars will continue to take the major share of gasoline car fleets for at least the next 10-20 years, it is necessary to establish and assess biocomponent options for them. Today, higher ethanol blending ratios are possible only with the use of flexible fuel vehicle (FFV) technology. The European Union requires renewable energy to have at least a 10% share of transport energy by 2020, and even higher shares are being attempted regionally. Biocomponents alternative or supplementary to ethanol are therefore desired in the gasoline pool. Interesting gasoline biocomponents are bioethers, biobutanols and biohydrocarbons. Oxygenated and non-oxygenated biocomponents can be combined to increase the bio-share of gasoline. This study consists of a literature review of the production processes, and an evaluation of the end-use performance of gasoline biocomponents. The results show that there are many options for increasing the bio-energy content of gasoline to 20% or more without increasing the gasoline oxygen content to a higher level than can be tolerated by E10-compatible gasoline cars.