Fuel cells are often touted as the power source for tomorrow’s vehicles. They typically burn the element hydrogen for their energy. But chemist Douglas MacFarlane of Australia’s Monash University champions a common alternative substance: ammonia.
An ammonia molecule is one nitrogen atom bonded to three hydrogen atoms. It stores about twice the energy of hydrogen. And MacFarlane has developed a gadget to make ammonia cheap and abundant.
His hand-size demonstration device combines nitrogen gas and water, zaps the mixture with an electric current, and the gizmo “exhales” pure ammonia gas. The gas could easily be cooled, bottled and shipped anywhere. When burned as a fuel, it converts back to hydrogen and nitrogen.
Making ammonia MacFarlane’s way requires a fair amount of electricity. But MacFarlane has that covered, too: his native Australia is a land of desert flats that could be populated with wind turbines and solar cells that could generate enough power to make the nation the Saudi Arabia of ammonia.
While MacFarlane’s invention is unlikely to take over the vehicle industry, it may have practical applications where fleets operate near sources of cheap, renewable electricity. More broadly, his work is a strong indication that engineers are rapidly creating workable alternatives to climate-changing fossil fuels, leading us to a post-petroleum world.