Transportation Biofuels: Green Gasoline, Bioethanol, Biodiesel and Green Diesel – A Comparison

Abstract

Green gasoline is basically a biomass-derived combustible liquid fuel that matches the broad volatility range of petroleum gasoline, viz. 40–140 °C, having a reasonable calorific value and other fuel properties with ultralow sulfur content and excellent octane rating. It should be readily miscible with petroleum. Scientists are attracted to biodiesel and hydrotreated vegetable oil or green (renewable) diesel to meet the need for renewable, sustainable and cleaner fuels in the diesel range. Approximately 20% of global energy is consumed by the transportation sector, making it the world’s largest oil consumer. Primary fuel sources have different chemical characteristics, which affect the behavior of liquid fuels. Transportation contributes significantly to global CO2 emissions through combustion of oil-derived fuels. Fuel sources are characterized by the presence or absence of certain oxygen, carbon, nitrogen and hydrogen atoms in their molecules. Liquid fuel can be produced from hydrogen, petroleum, ammonia, natural gas, biofuels, alcohols or even coal. The consumption of liquid fuels in the transportation sector is growing by 36 quadrillion Btu (diesel including biodiesel), the largest contributor being 13 quadrillion Btu by jet fuel and 9 quadrillion Btu by motor gasoline (including ethanol blends) annually. The market share of diesel fuel (including biodiesel) is likely to decline from 36% to 33% from 2012 to 2040, while the jet fuel market share will increase from 12% to 14%. This chapter discusses current statistics and advances in the transportation sector to provide detailed insights into the properties and mechanisms of various liquid fuels including green gasoline, bioethanol, biodiesel and green diesel.