Diesel, a fuel once derided as being too loud and too dirty, could be the key to clean, quiet and more environmentally friendly energy.
A Norwegian company, Nordic Power Systems, in conjunction with Cal Tech spin-off SAFCell Inc., recently released a new fist-sized, diesel-powered fuel cell that produces 250 watts of electricity, enough to power yachts or mobile homes. Scaled up, the researchers could use the fuel cells to power even more energy-hungry machines.
"Diesel is available most places, is not seen as a hazardous fuel in any way, has high power density, and (our new fuel cell) operates silently without any smell," said Tor Geir Engebretsen, the CEO of Nordic Power Systems.
A normal fuel cell converts hydrogen fuel into electricity in the presence of an oxidant and electrolyte. Storing pure hydrogen gas, however, can be a problem -- one reason why cars are still powered by gasoline instead of hydrogen. The tank for a hydrogen-powered vehicles would take up a far larger amount of space in the car compared to a gas tank.
Attach those hydrogen atoms to carbon atoms, however, and suddenly the same volume can hold a much larger amount of energy without high pressure. The high-energy density of these fuels, which include gasoline and diesel, is one reason internal combustion engines are found in cars, boats, generators and other places where space is limited and energy demand is high.
These engines do have their drawbacks, as anyone who has stood next to a Mac truck will tell you. Despite recent and significant advances, diesel engines have a reputation as being loud, smelly and bad for the environment.
The new diesel-based fuel cell, however, doesn't burn the hydrocarbon. Instead, it heats the fuel up to 160 degrees Celsius (320 degrees Fahrenheit), a process known as reforming.
The reformed hydrogen gas then passes into a fuel cell and is converted into electricity and heat. A diesel-powered fuel cell the size of a fist can produce about 250 watts of electricity. The larger the fuel cell, the more power it could produce.
"It's good science," said Raymond Gorte, a professor of materials science and engineering at the University of Pennsylvania and an expert in solid oxide fuel cells.
No matter what the scale, the new fuel cells would have a wide range of personal or commercial uses. "Some typical markets are battery charging like in trucks (related to ban on idle running), mobile homes, yachts, UPS systems, a number of defense applications and as range extender in electric/hybrid cars," said Engebretsen.