MNTRC Newsletter Vol 20, Issue 2: Fall 2013

Biodiesel reduces particulate matter for buses


Ashok Kumar, PhD, Chair, Department of Civil Engineering

Hamid Omidvarborna and conference visitor.

Hamid Omidvarborna (right) listens to a visitor discuss his poster at the AWMA 106th Annual conference during the Technical Poster session.

UNIVERSITY OF TOLEDO NEWS – In the past decade, biodiesel has become more prominent as an alternative renewable fuel to replace conventional fossil fuels in transportation. The University of Toledo (UT) had played a valuable role in conducting research related to biodiesel emissions from transit buses during the past eight years. Today, UT’s focus has shifted to examining the “Combustion Chemistry of Biodiesel for Use in Urban Transport Buses” under a research grant from the US Department of Transportation to the Mineta National Transit Research Consortium.

The project is directed by Dr. Ashok Kumar, Phd, Department of Civil Engineering, and Dong-Shik Kim, PhD, Department of Chemical & Environmental Engineering. Mr. Hamid Omidvarborna and Mr. Sudheer Kumar Kuppili are participating for their PhD and MS works, respectively. The two students presented individual posters at the Air and Waste Management Association’s (AWMA) 106th annual conference and exhibition in Chicago this past June 25-28.

Mr. Omidvarborna presented a technical poster, Analysis of Particulate Matter from the Exhaust of Biodiesel Transit Buses under Idling Conditions. The researchers performed idling tests on transit buses running on biodiesel. Meanwhile, they collected particulate matter (PM) from the tail pipe emissions.

New transit buses deliver positive net effect

Dr. Ashok Kumar and visitor.

Dr. Ashok Kumar explains a technical poster to a visitor at the AWMA 106th Annual Conference, Technical Poster session.

The results showed that PM emissions significantly decreased when using a biodiesel blend fuel, and that new transit buses had a positive impact on PM reduction whether their engines were running hot or cold. Updated results depicted that the maximum PM concentrations for ten different buses under hot and cold idling conditions were 2.77 µg/m3 and 5.59 µg/m3, respectively.

Among the more than 12 elements considered for elemental analyses, calcium, iron, and sodium dominated (77-85 percent by weight). Organic carbon to elemental carbon ratio (OC/EC) analyses indicated that higher OC was emitted during cold idling conditions (>%80) than in hot idling conditions (>%65). Furthermore, OC/EC ratio was higher in new buses with catalytic convertors (9.57-13.37) than in old buses without converters (1.85-4.55). Source-receptor analysis using positive matrix factorization showed that four sources – fuel, oil and lubricant, engine parts, and ambient air – contributed heavily to PM generation in the exhaust.

Mr. Kuppili presented a student poster – A Patent Review on Biofuels – that discussed various patents issued worldwide in the past few years. These patents were related to biofuel production methodologies, fuel properties enhancement, feedstock variations, and integrated biofuel production facilities that lead to the production of efficient and surplus biofuel with environmental friendly production and usage.

Relevant patent registrations on the rise

An increase in the number of new patent registrations was due to an increase in the number of researchers associated with biodiesel and biofuel production technologies in the past decade. New methods such as using nanoparticles and ultrasonic standing wave systems were established for extracting lipids from algae. Meanwhile, catalytic hydro-thermolysis, non-faradaic electrochemical modification of catalytic activity effect and combination esterification, trans-esterification, alcoholysis, hydrolysis, and fermentation for production of biofuel and enhancing fuel properties by functionalizing esters using epoxy esters with Chloroperoxybenzoic acid as catalyst.

Nearly 3 billion tons of biomass is required in 2050 to meet the envisioned 27 percent biofuel share in world transport fuel consumption. For example, Brazil and the USA met 23 percent and 10 percent of their road transport fuel demand through biofuel in 2011.

More research should help improve results

Biodiesel produced from oils had good fuel purity in combination with higher efficiency in the conversion rate. However, it appears that more research must be focused on using catalysts to enhance production efficiency. A more unified technology that can readily handle various feedstock types is necessary to develop an integrated system to manage different wastes.

In cases of the animal waste conversion to biofuels, the production efficiency of conversion to ethanol has not crossed 50 percent, while it is nearly 99 percent for biodiesel. So, for a trouble-free future for fuels, diverse feedstock should be identified and used, and advanced technologies that can process a variety of feedstock must be introduced. Of course, government and industry investments in biofuel are always encouraged.