Dual-fuel Operation of Compression-ignition Engine Using Biodiesel for Pilot Injection

Abstract

Economic factor and stringent emission standards are imposing constraints on current and future operation of power plants in the maritime industry. Hence, research institutions have intensified investigation on technologies for emission control and economy using alternative and sustainable/renewable fuels to achieve friendly environment. In this study, the combustion characteristics of natural gas and hydrogen fuelled compression ignition engine operated under stable condition using either neat or emulsified rapeseed methyl ester (RME) for pilot ignition were investigated. Ignition delay and rate of cylinder pressure rise at 1000 and 1500 r/min were obtained at various gas flow rates while the emission of NOx, CO2 and HC were measured. NOx concentrations were compared with the regulated IMO MARPOL73/78 and United States Environmental Protection Agency (EPA) Tier 3 standards and were observed to be lower than the MARPOL 73/78 level at both speeds and the EPA standard at 1500 r/min for the minimum specification of category 1 engines. Emulsified RME fuel pilot injection reduced NOx emission at all test conditions using natural gas. The use of hydrogen subscribed mainly in the reduction of particulate matters (PM) and CO2 and hence will contribute in the reduction of greenhouse effect (climate change) on the environment.