Combustion and emission characteristics of ammonia blended fuels in a spark-ignited engine

Abstract

Climate change and fossil fuel depletion has brought attention to the need for alternative fuels. Ammonia shows great potential as an alternative fuel because it is carbon-free and can be produced renewably. In this study the combustion and emission characteristics of ammonia blended fuels are investigated for spark ignited engines. Gasoline and heptane are explored as combustion promoters for ammonia. Experiments have been conducted on a single cylinder research engine fitted with an electronic dual fuel injection system. A parametric analysis has been conducted to investigate the effects of fuel blend ratio, engine speed, air fuel ratio, and spark timing. Blends with up to 70% ammonia have displayed good premixed combustion characteristics while reducing carbon emissions. Ammonia blends have been found to perform best at higher spark advances than baseline cases due lower flame speeds. The results show that ammonia blends are a promising alternative fuel option.