2. Realizing Clean Combustion with Ether Fuels

Efforts are being made throughout the world to minimize the environmental impact of everyday activities through governmental subsidies and regulations. The transportation sector especially has been a focus for policymakers as meeting future emission regulations with internal combustion engines increases system complexity and requires costly aftertreatment technology. For current on-road engines, the replacement of petroleum fuels such as diesel with alternatives that are produced from renewable sources can present an immediate impact on net CO₂ emissions. Ether fuels offer such renewability standards while containing high oxygen content (up to 50% by mass) and volatility favourable for smokeless combustion. In this research, dimethyl ether (DME) and oxymethylene ether (OME) fuels were investigated on a high compression ratio engine instrumented for single-cylinder engine research. The combustion characteristics and exhaust emissions of DME and OME fuels were analyzed and compared with diesel as a baseline reference. The test results show that ether fuels emit considerably less smoke. The storage and fuel handling of DME fuel present challenges for direct adaptation to current on-road diesel engines. On the other hand, blending OME with diesel fuel shows the potential to reduce anthropogenic CO₂ emissions conveniently and progressively.