Environmentally friendly buses

From The Battalion

By Alvis Wilson

Published: Monday, January 24, 2012

Students near the Trigon building may have noticed the curious lack of smog where the Aggie Spirit buses pick up and drop off passengers for seven different routes. Part of the reason for this is Transportation Services' use of biodiesel to fuel the fleet.

Biofuel describes any product derived from a plant-based substance, such as the commonly-used corn ethanol. Biodiesel can come from vegetable oil, algae oil and even animal fat. The most common source of biodiesel is derived from soybeans and peanuts.

Unlike traditional diesel, biodiesel is a renewable source of energy, created by mixing vegetable oil with alcohol to create fatty acid esters. The fatty acid esters in the biodiesel provide the energy density required to make an Sustainable Transportation fuel. Once this process is completed, the biodiesel is blended with traditional diesel and used in the transit bus system.

"We are using a B20 mixture: 20 percent biodiesel and 80 percent diesel," said June Broughton, marketing manager for Transportation Services.

The use of biodiesel, a well-maintained bus fleet and emission controls are all factors that cut down on emissions.

"Our entire fleet of transit buses range from year model 2001 to 2006, which all have computer-controlled diesel injection systems as well as computer-controlled automatic shift transmissions," Broughton said. "This helps to prevent lugging of the diesel engines, making it perform more efficiently."

Transportation Services began using biodiesel in July 2007. In October of 2005, the Texas Low Emission Diesel Program was created to regulate nitrogen oxide emissions in 110 Texas counties, including Brazos County. The program limits the maximum biodiesel mixture to 20 percent biodiesel and 80 percent diesel. Biodiesel reduces gas emissions for all gases except nitrogen oxide.

Lower emissions are not the only benefit to using biodiesel.

"We have noticed fewer diesel injector failures with B20. This may be explained by the added lubricity the biodiesel provides to the fuel," Broughton said.

Diesel fuel must act as a transportation fuel and add some lubricity to the moving parts in the engine. Since 1993, traditional diesel has been plagued by its lack of lubricity, primarily because of government regulation requiring producers to strip some components that are harmful to air quality. The addition of biodiesel into traditional diesel increases its overall lubricity.  

"The biodiesel used in the Aggie Spirit buses is just one of the green initiatives Transportation Services takes in order to support sustainability efforts in our community," Broughton said. "Transportation Services is committed to the University's green initiative and, of course, our University's focus on agriculture."

Using an agricultural product does have disadvantages.

Biodiesel must be scaled up to compete with the massive volume of traditional diesel consumed every day. There is also the question of whether biodiesel can be commercialized in a way that makes it a profitable product without large government subsidies.

The Texas A&M AgriLife Research is tackling these problems through research on algae — which can produce 10 times more oil per acre than any other plant, including soybeans and peanuts. The algae oil can be converted to biofuel and subsequently any type of transportation fuel, including biodiesel.

"The question is, how do we make it a commercially viable enterprise? And how do you scale it up from a laboratory to thousands of acres?" said Bob Avant, director of bioenergy programs and corporate relations.

With support from the Department of Energy, the Department of Defense, corporations and a four million dollar Texas Emerging Technology Fund grant, A&M Agrilife Research has built a multi-million dollar facility to conduct research on these problems.

"We have to demonstrate that it can be commercially scaled up and that it's economic," Avant said. "This is what A&M is so good at: we are good at farming and agricultural technology."