Abstract:
Alcohol fuels, primarily ethanol and methanol, have emerged as one of the
important alternatives for sustainable transportation and power generation
applications, due to the overall lower carbon dioxide (CO2) emissions. The
higher octane number of alcohol makes it suitable for spark ignition (SI)
engines while lower blend ratios can be used for compression ignition (CI)
engines as well. Since significant work and exploration have already been
performed for the application of alcohol in SI engines, the present study is
primarily focused on alcohol utilization in CI engines. This review majorly
consists of three parts: first, a discussion on the physical and chemical
properties of ethanol and methanol from the fuel perspective, second, combustion, and engine performance of CI engines fueled with alcohol and lastly,
emissions characterization of alcohol as fuel. A summary of this review is
provided which highlights the potential of alcohol utilization in the form of
blend or under dual-fuel combustion modes, as well as neat alcohol fueled CI
engine. Alcohol-fueled CI engine improves the soot-NOx trade-off characteristic in comparison to conventional diesel combustion, this fuel could be an
enabler to meet future emissions regulations. Overall lower CO2 emissions
(up to 15% lower compared to diesel) by utilizing alcohol as fuel make it
suitable for sustainable transportation.
