A case study of real-world tailpipe emissions for school buses using a 20% biodiesel blend.

Numerous laboratory studies report carbon monoxide, hydrocarbon, and particulate matter emission reductions with a slight nitrogen oxides emission increase from engines operating with biodiesel and biodiesel blends as compared to using petroleum diesel. We conducted a field study on a fleet of school buses to evaluate the effects of biodiesel use on gaseous and particulate matter fuel-based emission factors under real-world conditions. The field experiment was carried out in two phases during winter 2004. In January (phase I), emissions from approximately 200 school buses operating on petroleum diesel were measured. Immediately after the end of the first phase measurement period, the buses were switched to a 20% biodiesel blend. Emission factors were measured again in March 2004 (phase II) and compared with the January emission factors. To measure gaseous emission factors we used a commercial gaseous remote sensor. Particulate matter emission factors were determined with a combination of the gaseous remote sensor, a Lidar (light detection and ranging), and transmissometer system developed at the Desert Research Institute of Reno, NV, U.S.A. Particulate matter emissions from school buses significantly increased (up to a factor of 1.8) after the switch from petroleum diesel to a 20% biodiesel blend. The fuel used during this campaign was provided by a local distributor and was independently analyzed at the end of the on-road experiment. The analysis found high concentrations of free glycerin and reduced flash points in the B 100 parent fuel. Both measures indicate improper separation and processing of the biodiesel product during production. The biodiesel fuels used in the school buses were not in compliance with the U.S.A. ASTM D6751 biodiesel standard that was finalized in December of 2001. The U.S.A. National Biodiesel Board has formed a voluntary National Biodiesel Accreditation Program for producers and marketers of biodiesel to ensure product quality and compliance with the ASTM standard. The results of our study underline the importance of the program since potential emission benefits from biodiesel may be reduced or even reversed without appropriate fuel quality control on real-world fuels.

[1]  Richard E. Chase,et al.  Measuring Particulate Mass Emissions with the Electrical Low Pressure Impactor , 2006 .

[2]  R. Burnett,et al.  Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. , 2002, JAMA.

[3]  William R. Pierson,et al.  Particulate Matter Associated with Vehicles on the Road , 1976 .

[4]  Donald H. Stedman,et al.  AUTOMOBILE CARBON MONOXIDE EMISSION , 1989 .

[5]  C. Peterson,et al.  Emissions Characteristics of Ethyl and Methyl Ester of Rapeseed Oil Compared with Low Sulfur Diesel Control Fuel in a Chassis Dynamometer Test of a Pickup Truck , 1996 .

[6]  Martin Mohr,et al.  Comprehensive particle characterization of modern gasoline and diesel passenger cars at low ambient temperatures , 2005 .

[7]  Alan W. Gertler,et al.  Recent measurements of mobile source emission factors in North American tunnels , 1996 .

[8]  K. T. Knapp,et al.  Comparison of auto emission measurement techniques , 1996 .

[9]  J Dewulf,et al.  Exergy-based efficiency and renewability assessment of biofuel production. , 2005, Environmental science & technology.

[10]  P. Diaconis,et al.  Computer-Intensive Methods in Statistics , 1983 .

[11]  Chris Sharp,et al.  The Effect of Biodiesel Fuels on Transient Emissions from Modern Diesel Engines, Part I Regulated Emissions and Performance , 2000 .

[12]  Lisa D. Sabin,et al.  Relative Importance of School Bus-Related Microenvironments to Children’s Pollutant Exposure , 2005, Journal of the Air & Waste Management Association.

[13]  John B. Heywood,et al.  Internal combustion engine fundamentals , 1988 .

[14]  M. Jacobson.  Control of fossil‐fuel particulate black carbon and organic matter, possibly the most effective method of slowing global warming , 2002 .

[15]  J. Marshall,et al.  Vehicle self-pollution intake fraction: children's exposure to school bus emissions. , 2005, Environmental science & technology.

[16]  D. L. Reece,et al.  Long-range on-road test with twenty-percent rapeseed biodiesel. , 1999 .

[17]  Axel Munack,et al.  Influence of Biodiesel and Different Designed Diesel Fuels on the Exhaust Gas Emissions and Health Effects , 2003 .

[18]  P. Barber,et al.  On-road measurement of automotive particle emissions by ultraviolet lidar and transmissometer: instrument. , 2003, Environmental science & technology.

[19]  H Christopher Frey,et al.  On-Road Measurement of Vehicle Tailpipe Emissions Using a Portable Instrument , 2003, Journal of the Air & Waste Management Association.

[20]  Susan T. Bagley,et al.  EFFECTS OF AN OXIDATION CATALYTIC CONVERTER AND A BIODIESEL FUEL ON THE CHEMICAL, MUTAGENIC, AND PARTICLE SIZE CHARACTERISTICS OF EMISSIONS FROM A DIESEL ENGINE , 1998 .

[21]  Rolf D. Reitz,et al.  Effects of Biodiesel Blended Fuels and Multiple Injections on D. I. Diesel Engines , 1997 .

[22]  Judith C. Chow,et al.  PM-10 Exhaust Samples Collected during IM-240 Dynamometer Tests of In-Service Vehicles in Nevada , 1997 .

[23]  José Luis Jiménez-Palacios,et al.  Understanding and quantifying motor vehicle emissions with vehicle specific power and TILDAS remote sensing , 1999 .

[24]  P. Barber,et al.  Remote sensing of PM, NO, CO and HC emission factors for on-road gasoline and diesel engine vehicles in Las Vegas, NV. , 2003, The Science of the total environment.

[25]  P. Barber,et al.  On-Road Vehicle Particulate Matter and Gaseous Emission Distributions in Las Vegas, Nevada, Compared with Other Areas , 2004, Journal of the Air & Waste Management Association.

[26]  E. Zervas,et al.  Interlaboratory Test of Exhaust PM Using ELPI , 2005 .

[27]  S. Tyson,et al.  Biodiesel Handling and Use Guidelines , 2001 .

[28]  M. Graboski,et al.  Impact of biodiesel source material and chemical structure on emissions of criteria pollutants from a heavy-duty engine. , 2001, Environmental science & technology.

[29]  G. Bishop,et al.  Measuring the Emissions of Passing Cars , 1996 .

[30]  Robert L. McCormick,et al.  Combustion of fat and vegetable oil derived fuels in diesel engines , 1998 .

[31]  G. Bishop,et al.  IR long-path photometry: a remote sensing tool for automobile emissions. , 1989, Analytical chemistry.

[32]  R. Sepanski,et al.  TRENDS '90: A compendium of data on global change , 1991 .

[33]  R. L. McCormick,et al.  Preliminary Assessment of Quality and Stability of Neat Biodiesel in the USA , 2004 .

[34]  Claudio Mazzoleni,et al.  On-road measurement of automotive particle emissions by ultraviolet Lidar and transmissometer: theory , 2004 .

[35]  C. Peterson,et al.  CARBON CYCLE FOR RAPESEED OIL BIODIESEL FUELS , 1998 .