Fuel of Possibilities
From hydrogen to biofuels, researchers seek out powerful ideas for energizing tomorrow.
Solar energy is one way Daniel Raftery, professor of chemistry, sees us harnessing hydrogen power. He and his team are working on the critical step of developing a material that will capture as much solar energy as possible in as small of a package as possible.
"Biofuels are important not only for environmental reasons, but also for reducing our dependence on foreign oil and maintaining our national security," says Maureen McCann, associate professor of biology, whose research focuses on identifying genes to help design the optimum energy crop.
"The cell walls are the most important part of the plant for energy purposes," McCann says. "It is important to understand the composition of plant cell walls at the molecular level to be better able to break them down into the sugars used for generating fuels. By understanding the functions of genes involved in the production of biomass, we can alter or breed plants to grow larger and contain more of the materials that are useful for our fuel needs."
McCann says grasses will likely be the energy crops of the future because they require little fertilizer or water, are easily harvested, and continue to grow year after year. An additional advantage is the ability of grasses to grow tall very quickly, which allows for more plant material per acre of land.
"The goal is to produce 30 percent of all liquid fuel used in the U.S. from plants by 2030," McCann says. "We can't accomplish this using just the grain from the plant, we must use the body of the plant. The body, composed largely of cell walls, accounts for 60 percent of the mass of the plant."
In order for ethanol production to use the body of plant, which is more difficult to break down, additional treatment with enzymes is required to loosen its molecular structure before it is broken down into glucose.
"This process is not very efficient," McCann says. "We would like to engineer plants and microbes in ways that would eliminate the pretreatment steps and increase the end products of the process."
Better petroleumBetter use of current petroleum supplies is also on the horizon. Hilkka Kenttämaa, chemistry professor, has developed the first molecular-level method to completely analyze saturated hydrocarbons, large molecules that make up 70 percent of petroleum.
It is important to understand the molecular makeup to know how to refine the petroleum and what sorts of additives to use to improve the fuel properties, she said. This ultimately defines the overall economic value of petroleum.
"Prior to this, researchers could not tell the difference in the molecular level composition of petroleum obtained from different sources," Kenttämaa says. "This will result in better fuels that are more powerful, cleaner, and hopefully much cheaper than gasoline. It also could lessen the amount of fuel needed to power a car."
Kenttämaa, who leads the Energy Center's clean coal energy group, is also using the analysis method in work on the conversion of coal to clean liquid fuels. The end products are diesel fuels made up of saturated hydrocarbons.
"Researchers can change the conditions under which the fuels are produced and influence the molecular composition to obtain more desirable traits if they know the molecular composition and how it impacts the fuel performance," she says. "The goal is a clean energy source for transportation vehicles."
Kenttämaa's method can analyze hundreds of compounds in a few minutes and requires an extremely tiny amount of sample.
"Interdisciplinary work is the key to Purdue's success and the success of our nation," Kenttämaa says. "We must approach the problems from several angles, and collaboration across fields is essential. It is because Purdue fosters such research teams that we are leaders in the development of alternative fuels and are able to address the complex energy related challenges faced by society."
Elizabeth Gardner is a writer with Purdue University News Service.