A membrane that converts ammonia to hydrogen cheaply and efficiently has been described by one of its inventors as the last important piece in the puzzle to make widespread hydrogen cars viable. The technology has been demonstrated refueling two hydrogen cars, with plans for scaled-up versions. The work removes a major obstacle preventing hydrogen-fueled cars from competing on price with electric vehicles.
As the cost of solar power plummets, the world will soon have abundant cheap, clean energy. Unfortunately, it usually won’t be in the same time and place as the demand, shifting the focus to storage and transportation. Hydrogen, produced from water by electrolysis, has been widely proposed as the intermediary, with grand dreams of a “hydrogen economy” drawn up. However, the cost of moving it long distances is an obstacle.
Australia’s CSIRO is working to convert hydrogen to ammonia and back to hydrogen for use. There are inevitable costs and inefficiencies in both stages, but if these can be reduced sufficiently, they may be outweighed by the relative ease of transporting liquid ammonia.
To demonstrate their progress, CSIRO CEO Larry Marshall took a celebratory ride in a Toyota Mirai powered with hydrogen produced from ammonia using CSIRO's membrane technology.
"This is a watershed moment for energy," Marshall said in a statement.
Project leader Dr Michael Dolan told IFLScience that ammonia is stored as a liquid, a portion of which is allowed to vaporize to ammonia gas. This is drawn off and passed through their patented membrane, producing hydrogen and nitrogen. The hydrogen is pressurized and used to fill the cars. Reduced pressure in the ammonia storage container allows more liquid to vaporize until the entire supply is used.
Hydrogen cars produce no pollution, shedding only water, which allows us all to breathe easier. Unlike electric cars, they can refuel quickly – the demonstration took just three minutes – and can also travel further. The Mirai has a range of 550 kilometers (340 miles), and longer ranges are under development.
However, existing hydrogen cars are priced similarly to electric cars, with vastly more expensive fuel. Nevertheless, they have already gained a foothold in the Japanese and South Korean markets, and Dolan anticipates prices will fall dramatically as production scales up. However, hydrogen prices, currently much higher than petrol, also need to come down a long way if they are to compete, which is where this membrane could matter.
We’ve made ammonia for a century through the Haber-Bosch process, a centerpiece of modern industry. CSIRO have patented an alternative process that they think will prove more efficient, but Dolan said that the ammonia to hydrogen stage has been the biggest sticking point – one he hopes is now overcome.