Liquid Biofuels: Bioalcohols, Biodiesel and Biogasoline and Algal Biofuels

Abstract

AbstractThe development of alternative, renewable fuels is of global importance due to concerns regarding global warming, environmental protection and diversity and the security of energy supply. Liquid biofuels in particular, such as bioethanol and biodiesel, provide the potential for superior engine performance coupled with reduced particulate emissions, and are increasingly gaining acceptance and market share, particularly in the transportation sector. This chapter provides a concise review of the current knowledge on biodiesel and bioalcohols combustion science and technology. Liquid biofuels production technologies are reviewed and an overview is provided of current research efforts related to second‐ and third‐generation biofuels production and utilization, including hydrotreated vegetable oils (HVOs) and algal biofuels. An outline of the important physical and chemical properties of biofuels is also presented and discussed. Reliable performance and emissions predictions are very much dependent on the availability of fundamental experimental data and the performance of detailed chemical kinetic mechanisms. The combustion chemistry of ethanol is fairly well established and is reviewed in detail, and recent developments in the kinetic modeling of propanol and butanol isomers and of dimethyl ether are also presented. The combustion chemistry of biodiesel surrogates and actual biodiesel molecules is reviewed, as are the effects of using neat or blended biofuels on internal combustion engine performance and exhaust emissions. The feasibility of biofuels use in aviation is also explored. Finally, a brief review is provided of life cycle analyses that assess the environmental performance of liquid biofuels as compared to conventional fuels.