Australians Try to Tap New Power Source
At a laboratory in suburban Melbourne, Australian scientists have built tiny models of ceramic fuel cells that convert natural gas directly into electricity without using steam or turbines.
The chemical reaction yields 30% more electricity than the best conventional gas-fired plants and could power everything from a water pump to a city center, say the scientists developing the process and the consortium formed to commercialize it.
“If you’re lucky, average gas-power stations have 40% efficiency,” said Dr. Mike Murray, chief of the Commonwealth Scientific and Industrial Research Organization’s (CSIRO) materials science division in Australia.
Existing gas-fired power stations heat water into steam, which drives turbines that generate electricity. The new zirconia fuel cells utilize the mineral sand zircon, mixed with other exotic substances, to bypass this process, converting gas directly into power.
“Zirconia fuel cells can yield 60%,” Murray said.
The process also generates about 1,830 degrees of heat. If this heat is used to drive a turbine in the conventional way, the total system could yield efficiencies of 80%, scientists say.
The process is also “greener” than conventional gas-fired plants, producing only half of the carbon dioxide emissions.
It also emits much smaller quantities of nitrogen oxides, which are smog creators, and sulfur dioxide, a component of acid rain.
Potential applications are widespread, proponents say, and a consortium formed to commercialize the process expects to have large prototypes operating within seven years.
Partners in the venture are Australia’s largest company, resources and steel giant The Broken Hill Pty Co. Ltd., CSIRO, the government-owned New South Wales Electricity Commission utility and two state-owned research funding and analysis bodies.
Called Ceramic Fuel Cells Ltd., the venture plans to spend about $24 million developing the fuel cell technology over the next five years.
BHP’s Dr. John Parrott said the cells, should they prove commercially feasible, could allow companies to power large industrial complexes more efficiently, locate steelworks near iron ore bodies, power offshore oil rigs and propel seaborne tankers.
“Whenever we plan remote area operations, we always have to consider: ‘Do we set up our own power facility or buy power from the existing grid?”’ Parrott said.
In a modular form, the cells would power a remote operation more cheaply than using diesel generators or connecting the site to nearby electricity grids. As the operation grows, fuel cells can be stacked up to satisfy increased power needs.
Australia supplies 60% of the world’s zircon sands, from which the cells are made. Zirconia is tougher and lighter than steel, performs well in extreme heat and is used in high-wear applications like oil drilling and engine parts.
The first generation of fuel cells were used in spacecraft in the 1960s, utilizing phosphoric acid, but they proved very inefficient. Molten carbonate cells have also been studied.
The third generation of fuel cells, based on zirconia, is generically known as solid-oxide fuel cells.
Researchers in Japan and the United States are working hard to develop solid-oxide cells based on different zirconia mixes.
But the Australian group believes its mixture, for which it has proprietary rights, when combined with other components under development, gives the team a technological edge.
Because the cells operate at high temperatures, the ceramic components eventually degrade and have to be replaced.