Processing Magazine

Researchers develop more efficient, greener method to produce ammonia

August 12, 2014
<photocredit>Robert Kyllo/Hemera/Thinkstock</photocredit>

A new electrochemical process to produce ammonia simply from air and water has been developed by U.S. researchers.

As well as being more energy efficient than the traditional Haber-Bosch process, it is also more environmentally friendly.

Ammonia, or NH3, is made up of three parts hydrogen and one part nitrogen. Its main use is to make fertilizers, which help improve crop yields.

The Haber-Bosch process that is currently used to produce ammonia for synthetic fertilizer requires hydrogen, which is derived from processing natural gas. This method creates carbon dioxide as a byproduct. Moreover, according to an article in The Conversation, production of ammonia is very energy intensive, consuming nearly 2 percent of the world's energy supply.

Stuart Licht and colleagues at George Washington University recently demonstrated a relatively efficient electrochemical process in which water and nitrogen react directly to form ammonia. Their approach removes the need for an independent hydrogen generation step, Science magazine reported.

The new process takes place in molten salts like sodium hydroxide and requires a nanostructured iron oxide-derived catalyst. The method is claimed to use only two-thirds of the energy of the Haber-Bosch process and Licht expects to further reduce energy consumption in the future.

Licht's solution is not yet ready for industrial use. At the moment the catalyst suspension is only stable for a few hours. It does, however, point toward a way of producing ammonia from 100 percent renewable resources.