An oxygenating additive for improving the performance and emission characteristics of marine diesel engines

Abstract

Diesel engines provide the major power sources for marine transportation and contribute to the prosperity of the worldwide economy. However, the emissions from diesel engines also seriously threaten the environment and are considered one of the major sources of air pollution. The pollutants emitted from marine vessels are confirmed to cause the ecological environmental problems such as the ozone layer destruction, enhancement of the greenhouse effect, and acid rain, etc. Marine diesel engine emissions such as particulate matter and black smoke carry carcinogen components that significantly impact the health of human beings. Investigations on reducing pollutants, in particular particulate matter and nitrogen oxides are critical to human health, welfare and continued prosperity. The addition of an oxygenating agent into fuel oil is one of the possible approaches for reducing this problem because of the obvious fuel oil constituent influences on engine emission characteristics. Ethylene glycol monoacetate was found to be a promising candidate primarily due to its low poison and oxygen-rich composition properties. In this experimental study ethylene glycol monoacetate was mixed with diesel fuel in various proportions to prepare oxygenated diesel fuel. A four-cylinder diesel engine was used to test the engine performance and emission characteristics. The influences of ethylene glycol monoacetate ration to diesel oil, inlet air temperature and humidity parameters on the engine’s speed and torque were considered. The experimental results show that an increase in the inlet air temperature caused an increase in brake specific fuel consumption (BSFC), carbon monoxide, carbon dioxide emission, and exhaust gas temperature, while decreasing the excess air, oxygen and nitrogen oxide emission concentrations. Increasing the inlet air humidity increased the carbon monoxide concentration while the decreased excess air, oxygen and nitrogen oxide emission concentrations. In addition, increasing ethylene glycol monoacetate ratio in the diesel fuel caused an increase in the BSFC while the excess air and oxygen emission concentrations decreased.