A NEW form of clean and efficient energy could soon be powering hospitals and houses as scientists from Keele University design the energy machines of the future.
Fuel cells are revolutionary devices within which chemical energy is directly converted to electrical energy. Their invention means that inefficient power stations, in which energy is only indirectly converted to electricity by powering turbines, could one day become a thing of the past.
A number of fuel cells are already in use. In the United States, some buses and hospitals have already been fitted with them. But these are powered by hydrogen gas that Mark Ormerod, lecturer in chemistry at Keele University, says is prohibitively expensive.
He and his team are working to produce fuel cells that can run cheaply and efficiently on natural gas. The fuel cells being developed are the size of conventional gas boilers and are made of ceramic materials coated with electrodes.
At high temperatures, the ceramic material allows oxygen to pass through, turn into oxygen ions and thus gain electrons. Once they are inside the fuel cell the oxygen ions mix with natural gas, or methane, to produce carbon dioxide and water. The chemical energy of the reaction is liberated as electricity, which can be used to power circuits.
The production of hot water in the process means that the system can be self-generating, with the hot water used to sustain the temperature of the device and maintain the heated ceramic, enabling the process to occur in the first place.
Some of the hot water can be fed as steam back into the fuel cell where it reacts with the natural gas, the product of which only then reacts with the oxygen ions. Without a supply of steam the process would be impossible.
According to Dr Ormerod, the fuel cells tend to become clogged with carbon as they are used, reducing their potential shelf life.
The team is therefore working to design more tolerant anodes. These are the electrodes on the inside of the fuel cell. At the high temperatures within the device, a range of unwelcome reactions involving the natural gas can occur.
One being tackled is the decomposition of the methane on to the anode. Kevin Kendal, another chemistry department researcher, is working closely with Dr Ormerod to improve the properties of the ceramic materials.
"There are lots of groups worldwide working on this," Dr Ormerod says. "Commercialisation will definitely happen within five years. It is the fuel supply of the future."