The development of improved fuel specifications for methanol (M85) and Ethanol (E_d85)

摘要

Fuel alcohols, such as M85 (a blend of 85 percent by volume methanol with hydrocarbons) and E_d85 (a blend of 85 percent by volume denatured ethanol with hydrocarbons), are inherently involatile at low temperatures and may contain soluble or insoluble contaminants. We explored the adequacy of existing specifications for M85 and E_d85 by studying fuel effects on cold starting and vapor flammability, and fuel contaminant effects on materials compatibility and filter plugging. These studies demonstrated deficiencies in existing specifications. Therefore, we developed General Motors specifications for M85 and E_d85 to improve vehicle performance and durability. Key features include a Cold Starting Performance Index to improve wintertime starting, a conductivity and chloride ion specification to reduce corrosion, and a particulate contamination limit to reduce filter plugging.