Hydrogen on the Cheap
Wouldn’t it be nice to have a machine that could cheaply manufacture a gallon of gas per hour for your automobile? Envisioning the day when we may all have fuel cell cars, General Electric researchers have built a prototype that makes the equivalent quantity of hydrogen: plug it in, and it splits water molecules to generate one kilogram per hour of hydrogen.
The basic technology, called an electrolyzer, is nothing new: water is mixed with an electrolyte and made to flow past a stack of electrodes. Electricity causes the water molecules to split into hydrogen and oxygen gases. What GE has achieved is a potentially inexpensive, mass-manufacturable version of the technology.
Whereas traditional electrolyzers are made with expensive metals requiring hand assembly, a team at GE Global Research in Niskayuna, NY, came up with a way to make them largely out of a GE plastic called Noryl that is easy to form and resistant to the highly alkaline potassium hydroxide electrolyte. To get more hydrogen out of a smaller electrode, the researchers borrowed a spray-coating process normally used for jet engine parts to coat the electrodes with a proprietary nickel-based catalyst that has a larger surface area.
Their prototype of an easy-to-manufacture apparatus could lead to a commercial version that produces hydrogen via electrolysis for about $3 per kilogram – a quantity roughly comparable to a gallon of gasoline – down from today’s $8 per kilogram. “We’ve attacked the capital costs,” says Richard Bourgeois, an electrolysis project leader. GE could potentially manufacture the machines within a few years, he says.