Heavy-Duty Diesel Engine Performance and Comparative Emission Measurements for Different Biodiesel Blends Used in the Montreal BIOBUS Project

This paper reports the emissions measurement results of the BIOBUS project¹. Environment Canada's facilities at the Emissions Research and Measurement Division (ERMD) in Ottawa were used to conduct detailed emission measurements in order to compare the two engine types used by the urban transit bus operator in Montreal; Société des transports de Montréal (STM). The test engines were operated on 500 ppm sulphur diesel fuel, and biodiesel blends of 3 different origins (vegetable oil, animal fat and used cooking oil) at 2 different concentrations (5% and 20%). Tests were conducted using a 1998 and a 2000 model year, four-stroke, 250-HP, Cummins Diesel engines equipped with either a mechanical fuel injection pump or a computer-controlled electronic fuel injection system. All emissions tests were conducted with a degreened diesel oxidation catalyst in place, as is typical for the STM buses purchased from Nova Bus. Particle size distribution measurements and extensive chemical analysis were performed in addition to the regulated emissions.

The biodiesel evaluation was a joint effort by the Canadian Renewable Fuels Association, the Fédération des producteurs de cultures commerciales du Québec, Rothsay/Laurenco, and STM, with the support of the Canadian Federal and Quebec Provincial governments. The use of biodiesel was evaluated in severe climatic conditions (from -31°C to +31°C) on 155 urban transit buses for one year from March 2002 to March 2003. In addition to assessing the viability of the fuel during routine operation of a bus fleet that operates in a cold climate, the project also endeavoured to evaluate the potential environmental benefits of biodiesel.