Influence of the Methanol Fuel Composition on Performance and Exhaust Emissions of Diesel—Derived Alcohol Engines

This paper descibes the application of straight alcohol fuel concepts to diesel engines while evaluating the influence of methanol fuel composition on performance and exhaust emission behavior. A thermodynamic analysis of the cylinder pressure was conducted and the exhaust emissions both, gaseous and particulate, were measured.

The results show that, with respect to future emission standards and requirements for a very low emission engine concept for heavy duty application, alcohol fuels should contain the smallest concentration of higher alcohols and hydrocarbons possible. Alcohol fuels containing higher alcohols exhibit better self-ignition properties, but NO_x, HC, and aldehyde emissions are also observed to increase over levels obtained with methanol.

Of the straight methanol fuel concepts presented in this paper, only the glow plug assisted methanol engine is expected to meet the 1994 U.S. EPA heavy duty standards for gaseous and particulate emissions.