Researchers at the University of Massachusetts Lowell developed a technique that uses only water, carbon dioxide and cobalt metal particles that have surface nanostructures measuring billionths of a meter in size, to produce hydrogen on demand at relatively low temperature and pressure and to use to power the next generation of electric vehicles.
According to David K. Ryan, the project’s principal investigator, hydrogen can be used in fuel cells, which combine hydrogen with oxygen from the air to produce electricity at up to 85% efficiency.
“Other investigators have used all kinds of methods to produce hydrogen, such as electrolysis, natural gas reforming and even metals such as zinc, iron and nickel with acids, but not catalytically with cobalt,” Ryan said in a media statement. “The carbonate is involved in the reaction but it doesn’t change or get consumed; it just helps facilitate the conversion of the cobalt metal to cobalt oxide, and this conversion produces the hydrogen and carbon dioxide.”
The scientist explained that the experimental setup consists of a stainless steel canister filled with cobalt. A carbonate solution made from carbon dioxide and water is pumped through the canister and then warmed up to about 150 degrees. The solution is also compressed to about three atmospheres, or 45 pounds per square inch, which is about the same pressure as in a car tire.
“Under these relatively low-temperature and modest-pressure conditions, we were able to produce hydrogen efficiently, to nearly 70%. Subsequent work has allowed us to produce hydrogen at greater than 95% purity,” Ryan said.
The researcher explained that in an electric car, the hydrogen from the canister can go directly to the fuel cell, where it is mixed with oxygen from the atmosphere to produce electricity and water. The water can then be looped back into the canister and mixed with the carbonate to form the catalytic solution. The electricity produced by the fuel cell can be used to power the canister’s pump, heater and compressor, as well as the car’s electric motors, rechargeable storage battery and headlights.
“This process doesn’t store any hydrogen gas, so it’s safe and poses no storage or transportation issues. Once you stop the flow of the carbonate solution or release pressure in the reaction chamber, the hydrogen production stops, so hydrogen is produced only as needed,” Ryan said.
The experts suggested that once the cobalt metal in the canister is used up – that is, converted to cobalt oxide – the car driver can swap out the canister with a new one every 300 to 400 miles. The cobalt in the old canister can then be regenerated, using a renewable energy source such as wind or solar.
“So instead of going to a gas station to get a fill-up, you can go to a ‘refueling’ station and get a new canister. You can also bring extras for long trips,” Ryan said.