Ohio University engineers are leading one of the first comprehensive efforts to examine how fuel cell technology could pave the way for cleaner coal-fired power plants.
Supported by a $4 million US Department of Energy grant, the project aims to find ways to use coal – the environmentally dirtiest but most abundant fossil fuel in the world – to harness high-efficiency fuel cells.
Most government-sponsored energy research in the US is focused on using natural gas to power fuel cells because it is the cleanest burning of all the fossil fuels. Ohio University researchers, however, say it’s critical to begin exploring ways to use coal as a catalyst for fuel cells because it is more abundant and less expensive than natural gas.
‘We need to find ways to make coal work for us,’ said David Bayless, an associate professor of mechanical engineering in the Russ College of Engineering and Technology and director of the Ohio Coal Research Center. ‘After all, coal reserves are expected to last for at least the next 250 years, compared to 30 years for natural gas.’
Fuel cells are electrochemical devices that convert chemical energy into electricity and heat. Like a battery that never needs recharging, a fuel cell will run indefinitely as long as chemical energy is present. There are several different types of fuel cells, but they’re all based on a central design that consists of two electrodes sandwiched around an electrolyte.
Fuel cells appeal to many in the energy industry because they generate electricity with little pollution and are highly efficient, using 80 to 90 percent of their energy compared to a 40 to 50 percent productivity rate with traditional combustion. The Ohio University project is part of a larger national effort by the US Department of Energy’s Hydrogen, Fuel Cells and Infrastructure Technologies Program to study and develop viable fuel cell power.
Bayless and other researchers in the Ohio Coal Research Center propose teaming fuel cells with coal-derived gas, or syngas. Rather than burning coal directly, coal gasification mixes coal with steam, air and oxygen under high temperatures and pressures, resulting in chemical reactions that form a gaseous mixture of hydrogen and carbon monoxide. When introduced to fuel cells, this gas is transformed into water, producing electricity and heat in the process.
But because syngas contains hazardous contaminants such as sulphur and mercury that can damage fuel cells, Ohio University researchers need to figure out how to effectively integrate syngas with fuel cells.
During the next few years, they plan to conduct experiments to see how various syngas contaminants affect fuel cells by measuring decreases or changes in fuel cell voltage, temperature, pressure and other performance-related factors.
‘Once we figure out what’s happening, we can try to create better, stronger fuel cells that can withstand these contaminants or test various ways of reducing coal contaminants using current cleaning technology,’ said Assistant Professor of Chemical Engineering Gerardine BÃ¶tte, who is helping Bayless conduct experiments. ‘At this point, though, we don’t know where our research will take us.’
Bayless is focusing on integrating syngas with planar solid oxide fuel cells, which are tile-shaped cells made of ceramic. But he sees coal eventually becoming an energy source for a variety of high-tech fuel cells being developed to power automobiles, laptops and homes.
‘I have a larger vision for coal that includes applications in many areas,’ Bayless says. ‘It’s exciting because not much is known in this field, so this gives us a chance to explore some new ideas.’
One idea, he adds, is to merge the fuel cell work with another Ohio University project that uses algae to control greenhouse gas emissions from coal-fired power plants. The harvested algae could be converted into hydrogen, which would then be used to power the fuel cells, he explains.