Fuel Cell Sandwich Generates Excitement
After all the hype about fuel cells, there it is, a “revolutionary” invention to ease the energy shortage and spare the environment, and it looks about as sophisticated as a waffle iron.
On a counter in a USC chemistry lab rests a black metal sandwich with a thin tube connecting it to a vial of wood alcohol. Squeezed between the steel plates are a few drops of the alcohol, a plastic wafer and some platinum-coated mesh.
The impressive thing, the novelty that earned its inventors a patent and inspires their vision of the future, is that this soggy contraption generates electricity--at the moment, 1.5 watts, according to the readout on a digital meter.
That’s enough to run a mobile phone, Robert Aniszfeld, a USC researcher, said while demonstrating the device. And, he added, that’s plenty of power to continue testing this long-sought technology, called a methanol fuel cell, which generates a current from electrochemical reactions involving methanol, platinum and oxygen.
The concept is so attractive in these energy-hungry times that USC’s Loker Hydrocarbon Institute and the Jet Propulsion Laboratory have formed a new company to capitalize on it. A team of researchers from the two institutions patented a version of the technology in 1997.
The company, DM-Power, is the first commercial venture between the university and JPL, said Cornelius Sullivan, USC’s vice provost for research. The goal is to speed development of commercial methanol fuel cells for small and medium applications, from mobile phones to auxiliary generators, said Aniszfeld, who serves as the company’s chief executive.
The Department of Defense, which funded much of the early research on the technology, has tested portable generators that use a methanol fuel cell based on the USC-JPL design. In theory, the power packs--about the size of a shoe box--would enable soldiers to run several instruments for long stretches without having to recharge.
But getting the methanol fuel cell out of the lab will be a major challenge, researchers say. “Clearly it will have a market, but there are a lot of technical issues still to work out,” said Subhash Singhal, director of fuel cell development at the Pacific Northwest National Laboratory in Richland, Wash.
Similarly cautious is Tom Zawodzinski, a chemist doing fuel cell research at the Los Alamos National Laboratory. “It’s a field that has a lot of promise, but it’s not quite as ripe as might be hinted out there,” he said.
The idea of using controlled chemical reactions to generate electricity is more than a century old. It was in the last energy crisis in the 1970s that scientists and environmentalists began heavily promoting fuel cells as potentially abundant sources of clean power.
Fuel cells convert a hydrogen-containing fuel into electricity and heat. The system is quiet and creates little waste pollution. Like a battery, a fuel cell has a limited capacity to create a current. Unlike a battery, a fuel cell isn’t thrown out or recharged when its available electrons are used up--its fuel is replenished.
Efforts to develop the technology have long focused on devices that use hydrogen gas, the cleanest, most efficient fuel. NASA has used hydrogen technology for decades. It powers space shuttle electronics. Car companies have spent an estimated $2 billion in recent years to test hydrogen-powered cells for electric cars.
The drawback is that hydrogen gas is highly explosive and must be stored in heavy pressurized tanks. To address safety and distribution problems, some automotive engineers are developing hydrogen fuel cells that use methanol for an intermediate stage.
A car’s tank would be filled with methanol, which would then be converted on board to hydrogen gas for generating electricity.
But other researchers, including those at USC and JPL, use methanol directly. Methanol has promise as a power source because, ounce for ounce, its chemical bonds store nearly 10 times more potential electrical energy than does a nickel-hydride battery.
The challenge for engineers is to tap that energy in a cheap and handy way that competes favorably with batteries and internal combustion engines.
Advocates imagine niche uses for the technology. A digital phone running on a methanol fuel cell, for example, would have to have the fuel replenished--perhaps in the form of a methanol-containing cartridge--about once a month, Aniszfeld said.
Alternatively, some engineers are aiming for chargers that run on methanol fuel cells, allowing mobile phones or other hand-held devices with run-down batteries to be revived when plugging into the electric grid is impossible, said Zawodzinski, of New Mexico’s Los Alamos lab.
Still, he cautioned against the “hype” that has surrounded fuel cell technology for decades. They’re very promising, but not the panacea that some advocates suggest.
Among the technical obstacles is how to miniaturize the fuel cell without losing efficiency. And engineers are still wrestling with how to build small electronic devices that can dispose of the methanol cell’s waste products, water vapor and carbon dioxide.
Cost also comes into play. Using today’s designs, a direct methanol fuel cell big enough to power a car would cost at least $5,000 for the platinum alone, said JPL scientist Sekharipura Narayanan.
But backers of fuel cells include some researchers with impressive credentials. George Olah, a founder of the university’s Loker Institute and one of the scientists on the USC-JPL team, called the methanol fuel cell “revolutionary.” It’s hard to write off his enthusiasm as an advocate’s zeal. He was awarded the 1994 Nobel Prize in chemistry.
“Fuel cells in small packages will be able to provide power for a lot longer than any battery you can dream about,” he said. “They will become reality. Eventually, it will also become a reality to have cars with them.”
He envisions factory and power plant smokestacks outfitted with equipment that converts carbon dioxide, which may play a role in global warming, into methanol. That could ease energy concerns and reduce pollution at the same time.
“I may be a dreamer,” he said, “but I’m a reasonable dreamer.”
