Comparison and Characterization of the Atmospheric Emissions Produced by Combustion of Petrodiesel, Methyl Ester of Soybean Oil and Methyl Ester of Used Oil

摘要

Diesel is the third most consumed fuel in Mexico (20%) with increasing trend. The exhaust pollutant emissions from diesel engines are evaluated in about 35% of total ambient emissions. This study explores the possible use of biodiesel and provides technical and environmental data to support future feasibility studies. Additionally, experimental work compares exhaust emissions from petroleum diesel and biodiesel (methyl ester) fuels using a VW engine. In the first phase, biodiesel was produced from soybean, coconut and used oils considering two chemical reaction temperatures, 25°C (ambient) and 65 °C. Elaborated biodiesel was blended with low sulfur petroleum diesel in a ratio (20/80). In the second phase, chemical and physical properties were obtained in each type of fuel and their blends were characterized by important parameters in the fuel quality. And the third phase, exhaust emissions was measured from 4-cylinder VW engine, with direct injection rate of 90 hp @ 4,000 rpm and peak torque of 149 ft-lb @ 1900 rpm. The experimental procedure was elaborated considering that vehicular emissions are affected by several factors as fuel quality, motor speed, and engine load. In general, the experimental results indicate that biodiesel and blends of biodiesel with petrodiesel emit lower pollutant concentrations of CO, total hydrocarbons, and NO_x.