Liquid Sunshine Science 6398 120
http://science.sciencemag.org/content/361/6398/120
Liquid sunshine
Robert F. Service
Science 13 Jul 2018:
Vol. 361, Issue 6398, pp. 120-123
DOI: 10.1126/science.361.6398.120
Summary
Renewable energy sources, such as wind and solar electricity, are the
fastest growing energy sources in the world. But the sunniest and
windiest spots on Earth are often far from cities where the power is
needed, and there are few effective ways to ship electricity over long
distances. That leaves much of the world's renewable energy potential
untapped. Now, researchers are looking to use renewable electricity to
make ammonia, which is already produced on an industrial scale as the
main ingredient in fertilizer, and shipped worldwide. Today, ammonia is
made primarily by stripping hydrogen molecules from natural gas and
combining them with nitrogen purified from air, a process that generates
about 1% of all humanmade carbon dioxide. In the future, ammonia could
be produced by combining that nitrogen with hydrogen generated by
splitting water. Devices called reverse fuel cells could also make it
directly by using electricity and catalysts to split water and combine
the hydrogen with nitrogen. These advances could enable ammonia to be
produced economically on a small scale, allowing farmers to make their
own fertilizer and renewable energy producers to store any excess power
they may have and ship it where it's needed.