MNTRC Newsletter Vol 20, Issue 1: Spring 2013

Is biodiesel cleaner for buses than conventional diesel?


Ashok Kumar, PhD, Chair, Department of Civil Engineering

Collecting tailpipe particulate matter on filter paper.

Filters on exhaust systems help researchers analyze emissions.

UNIVERSITY OF TOLEDO NEWS – Biodiesel is an alternative fuel with growing use in transportation. But is it cleaner than conventional diesel? Here at the University of Toledo (UT), we have been involved in research on biodiesel emissions for the last eight years. Currently, UT is working on a project called Combustion Chemistry of Biodiesel for the Use in Urban Transport Buses.

Filters measure bus emissions

The research involves testing the buses that are used every day by the Toledo Area Regional Transit Authority (TARTA), with the help of Mr. Steve Atkinson, TARTA Director of Marketing. We chose the 700 and 800 bus series because our earlier work was done on the 300 and 500 series. The buses we chose are fairly new. Although the 700 series buses are older, their engines were remanufactured a few years ago.

The 800 series are brand new, and a large catalytic converter was added to the bus to improve exhaust emission quality. We collected tailpipe particulate matter (PM) on filter papers and measured total particulate mass (TPM). Elemental analysis of PM collected on the filter papers was carried out by an accredited analytical laboratory.

Filter paper before and after emissions collection.

Emissions test filter papers before (left) and after (right) testing.

Biodiesel reduces PM emissions

The results showed that PM emissions significantly decreased when using biodiesel blend fuel, and newer transit buses have a positive impact on PM reduction. More than 12 elements were considered for analysis, and the results showed that calcium (Ca), ferrous (Fe), and sodium (Na) were found in the maximum concentration.

Research results are expected to contribute to a better understanding of biodiesel combustion chemistry and to a further reduction of biodiesel emissions. The field tests are taken along with lab tests and modeling studies.

Kumar and Kim direct the project

The project is being directed by Dr. Ashok Kumar, Department of Civil Engineering, and Dr. Dong-Shik Kim, Department of Chemical & Environmental Engineering. Mr. Hamid Omidvarborna and Mr. Sudheer Kumar Kuppil are participating in the project for their PhD and MS work, respectively.

Funding is through a research grant from the US Department of Transportation, Research and Innovative Technology Administration, administered by the Mineta National Transit Research Consortium (MNTRC)