Hydrogen-powered vehicles have been pitched as a greener alternative to gas-powered vehicles, but one problem with this is that the hydrogen is typically produced from a fossil fuel—natural gas—in a process that releases a lot of carbon dioxide.
BASF, the world’s largest chemical company, may have a solution. It’s developing a process that could cut those emissions in half, making hydrogen fuel-cell vehicles significantly cleaner than electric vehicles in most locations (the environmental benefits of electric cars vary depending on how the electricity is generated). Beyond providing a cleaner source of hydrogen for fuel-cell vehicles, the process could also help clean up industrial processes, like oil refining, that use large amounts of hydrogen.
BASF is working on a pilot plant to demonstrate the technology as part of a $30 million project partially financed by the German government. A second part of the project will demonstrate a new way to use carbon dioxide emissions as a raw material for chemicals and fuels, by combining them with the hydrogen produced in BASF’s low-carbon emissions process.
Taken together, the systems could create new markets for natural gas, especially in the United States, where fracking has led to a boom in production. A cleaner form of hydrogen could also revive stronger interest in fuel-cell vehicles. A handful of automakers have plans to start selling fuel-cell vehicles as early as 2015 (see “Why Toyota and GM Are Pushing Fuel-Cell Cars to Market”). Conventional hydrogen production involves reacting methane—the main ingredient of natural gas—with oxygen or water. This reaction produces hydrogen gas and, as the carbon reacts with oxygen, carbon dioxide.
Researchers have known for a long time that it’s possible to form hydrogen without introducing oxygen, avoiding carbon dioxide production. At high-enough temperatures, methane forms hydrogen and solid carbon. (The carbon can be used in industrial processes, such as making steel.) But this approach hasn’t proved economical.
That’s partly because generating high temperatures requires a lot of energy, and producing that energy usually involves carbon dioxide emissions, which would offset much of the potential environmental benefit. BASF has found better ways to recycle heat within its system, greatly decreasing the amount of energy needed. “The hydrogen production will be cost-competitive, while at the same time having the added advantage of having a reduced carbon footprint,” says Andreas Bode, the BASF project coordinator.
BASF is working with ThyssenKrupp Steel to use the carbon produced in the process in steel manufacturing.
The second part of the project is using the hydrogen to make useful products from carbon dioxide. In the presence of novel catalysts developed by BASF, hydrogen and carbon dioxide form syngas, a mixture of mostly carbon monoxide and hydrogen. Syngas is used to make methanol and other chemicals and fuels. Using hydrogen produced in a way that produces relatively little carbon dioxide helps keep overall emissions low. The basic reaction has been known for some time, but BASF thinks its new catalysts—the details of which it is keeping to itself—can make it economical. “It’s really a breakthrough,” Bode says.
Though finding such uses for carbon dioxide will do little to dent overall greenhouse gas emissions, the process could be important because it could allow chemical producers to use alternatives to petroleum.