Engine performance and exhaust emissions from a diesel

Abstract

Non-road diesel engines are significant contributors to air pollution in the United States. Recent regulations put forth by EPA and other environmental agencies have laid out stringent guidelines for engine manufacturers and fuel producers. Recent increases in oil prices and foreign energy dependency has led to a push to produce renewable fuels, which will supplement current reserves. Biodiesel is a clean-burning renewable fuel, that can be blended with petroleum diesel. It is important to understand the effect on engine performance and exhaust emissions when using biodiesel from different feedstocks. The objective of this research was to determine the relationship between engine performance and emissions and cottonseed oil biodiesel used in a diesel engine rated for 14.2 kW. When using cottonseed oil biodiesel blends, CO, hydrocarbon, NOx, and SO2 emissions decreased as compared to petroleum diesel. Carbon dioxide emissions had no definitive trend in relation to cottonseed oil biodiesel blends. Carbon monoxide emissions increased by an average 15% using B5 and by an average of 19% using B100. Hydrocarbon emissions decreased by 14% using B5 and by 26% using B100. Nitrogen oxide emissions decreased by four percent with B5, five percent with B20, and 14% with B100. Sulfur dioxide emissions decreased by an average of 86% using B100, and by 94% using B50 blended with ultra-low sulfur diesel. The difference between peak output power when using biodiesel and diesel was insignificant in blends less that B40. Peak measured power using B100 was about five percent lower than for diesel fuel. Pure cottonseed oil biodiesel achieved and maintained a peak corrected measured power of 13.1 kW at speeds of 2990, 2875, and 2800 rpm at loads of 41.3, 42.7, and 43.8 N-m. Using B5 produced a peak power of 13.6 kW at 2990 rpm and 43.9 N-m and at 2800 rpm and 46.7 N-m, while using B20 produced a peak power of 13.4 kW at 2990 rpm and 43.7 N-m. Brake-specific fuel consumption at peak measured load and torque using B100 was 1238 g/kW-h. Brake-specific fuel consumption at peak measured power and loads using B5 and B20 were 1276 and 1155 g/kW-h.