ABSTRACT
This chapter provides the information which may be useful for developing fuel-efficient, eco-friendly, dedicated biofueled spark-ignition engines. The main biofuels for spark-ignition engines are: liquid biofuels, such as, methanol, ethanol, butanol; and gaseous biofuels, such as, biogas, hydrogen. Alcohol fuel is called octane booster because the octane number of gasoline fuel can be increased by blending it with methanol, ethanol, or butanol. The chapter discusses the advantages and disadvantages of Biofuel Use in Spark-Ignition Engines. The thermal efficiency of a spark-ignition engine fueled with methanol at 2500 rpm increases from 22" with a compression ratio of 6:1 to 30.5" with a compression ratio of 10:1 due to higher flame speed of methanol, less compression work due to higher heat of vaporization, and the presence of oxygen in methanol. The use of raw biogas as a fuel in spark-ignition engines would lead to the following problems: Power Drop, and Less Thermal Efficiency.
