Science Publishes Feature Article on Ammonia Energy

On July 13, Science magazine, the flagship publication of the American Association for the Advancement of Science (AAAS), published a 2,800-word feature article on ammonia energy. The article, headlined, “Liquid sunshine: Ammonia made from sun, air, and water could turn Australia into a renewable energy superpower,” is uniformly open-minded and upbeat.  Its opening section ends with a quote from Monash University Professor of Physics and Chemistry Doug MacFarlane: “’Liquid ammonia is liquid energy,’ he says. ‘It’s the sustainable technology we need.’”

MacFarlane helped launch the Australian chapter of the NH3 Fuel Association, the organization that publishes Ammonia Energy.

The article’s author is Robert F. Service, “a news reporter for Science in Portland, Oregon, covering chemistry, materials science, and energy stories,” according to the publication’s Web site.  Science publishes both journalistic reportage and peer-reviewed papers across the spectrum of scientific disciplines.  The AAAS estimates that more than 500,000 people read the journal every week.

Members of the ammonia energy community will be familiar with much of the article’s content.  It sets the stage with a sweeping prospect:

Australia boasts a renewable energy potential of 25,000 gigawatts, one of the highest in the world and about four times the planet’s installed electricity production capacity. Yet with a small population and few ways to store or export the energy, its renewable bounty is largely untapped.
Liquid sunshine, Science, 13 Jul 2018: Vol. 361, Issue 6398, pp. 120-123.

A survey follows of efforts to tap the bounty, underway or announced, at Australia’s Federal and state levels, including the Australian Renewable Energy Agency’s AUD $20 million (USD$15 million) program of grants for development of renewable hydrogen technologies (covered here by Ammonia Energy); the contemplated development of ammonia facilities at the port of Gladstone in Queensland (foreshadowed here by Ammonia Energy); and hydrogen infrastructure developer Hydrogen Utility’s plans for a renewable hydrogen and ammonia plant in South Australia (covered here by Ammonia Energy).  One development previously unreported by Ammonia Energy is the possible inclusion of a renewable ammonia component in the massive Asian Renewable Energy Hub project in Western Australia. “Although most of the project’s 9000 megawatts of electricity would flow through an undersea cable to power millions of homes in Indonesia, some of that power could be used to generate ammonia for long-distance export,” according to the Science reporting.

Mentioned later is the news that “Japan, Singapore, and South Korea have all begun discussions with Australian officials about setting up ports for importing renewably produced hydrogen or ammonia.”

The article then delves into ammonia production technology, jumping off from Yara’s Pilbara plant in Western Australia.  The plant was commissioned in 2006 with traditional Haber Bosch technology.  In September 2017 Yara announced (and Ammonia Energy reported) that it was studying the possibility of co-locating on the Pilbara site a demonstration plant that would produce ammonia using solar power.  The article states that “the new add-on will feed power from a 2.5-megawatt solar array into a bank of electrolyzers,” which will reduce “total CO₂ emissions from the process.”  (The actual CO2 accounting in the article is incorrect.)

The reference to the solar array and electrolyzer bank goes beyond Yara’s announced plans, which have not been updated since Yara’s Chief Executive Officer Svein Tore Holsether spoke with The Australian during a visit to Perth in November 2017 (“Yara plan for ‘renewable’ outback ammonia plant”).  At that time, Holsether said that “It’s still at the very early stages — it’s not at industrial feasibility yet — but we are looking at ways to produce [ammonia] through renewables.  Solar could be one such avenue and it would be very exciting if we could look into a pilot plant operation to look at the feasibility of this to bring it up to industrial scale . . . The Pilbara region is very suitable for solar-based production of ammonia with ample sun and land availability, and with our existing operation there it fits well.”  A Green Energy Tribune story in May 2017 mentioned that Yara was “working towards a trial involving a 2.5MW solar array to power its electrolysis process,” but this was never verified by the company.

Yara is an industry member of the NH3 Fuel Association.

The discussions of conventional and electrolytic Haber Bosch serve as a foundation for a detailed description of MacFarlane’s electrochemical technology (covered here by Ammonia Energy).  The article cites a November 2017 Energy & Environmental Science paper by Fengling Zhou, MacFarlane, and eight coauthors about an electrochemical cell that, via “the use of ionic liquids that have high N2 solubility as electrolytes, [was able] to achieve high conversion efficiency of 60% for N2 electro-reduction to ammonia on a nanostructured iron catalyst under ambient conditions.”

Also cited is an April 2018 ACS Energy Letters paper by Bryan H.R. Suryanto, MacFarlane, and seven coauthors that describes a refined electrode-electrolyte system consisting of “α-Fe nanorods grown on carbon fiber paper” that serve as “cathodes in an aprotic fluorinated solvent–ionic liquid mixture.”  This system delivers “significantly enhanced” nitrogen reduction activity at room temperature and atmospheric pressure “with an NH₃ yield rate of ∼2.35 × 10^–11 mol s^–1 cm_GSA^–2, (3.71 × 10^–13 mol s^–1cm_ECSA^–2) and [nitrogen reduction] selectivity of ∼32%.” (“GSA” refers to geometric surface area and “ECSA” refers to electrochemical surface area.)

In the process of contextualizing MacFarlane’s work, the article mentions a number of prominent individual and institutional members of the ammonia energy community, including Grigorii Soloveichik, head of the U.S. Department of Energy’s ARPA-E REFUEL program; Lauren Greenlee, Assistant Professor of Chemical Engineering at the University of Arkansas; Tim Hughes, Principal Scientist for Energy Storage at Siemens and an architect of its recently commissioned green ammonia demonstration in the U.K.; and Ryan O’Hayre, Professor of Metallurgical and Materials Engineering at the Colorado School of Mines.

The article’s final topic is a status update on the high-purity ammonia-to-hydrogen conversion technology that has been developed by Michael Dolan and his team at the Commonwealth Scientific and Industrial Research Organization (CSIRO) (described here by Ammonia Energy):  “Next month, [Dolan] plans to demonstrate the reactor to automakers … He says his team is in late-stage discussions with a company to build a commercial pilot plant around the technology.”

As it happens, on July 13 CSIRO emailed invitations to the “world-first demonstration of vehicle refuelling with hydrogen derived from ammonia.”  The event, at which “guests will have the opportunity to witness the refuelling process and to ride in the latest-generation hydrogen fuel cell vehicles from Toyota and Hyundai,” will take place on August 8.

The article closes with a view into the long-term future, courtesy of Brett Cooper, co-founder of Australian renewable energy developer Renewable Hydrogen PTY:

Maybe 30 years down the road, Australia’s coast [could be] dotted with supertankers, docked at offshore rigs. But they wouldn’t be filling up with oil. Seafloor powerlines would carry renewable electricity to the rigs from wind and solar farms on shore. On board, one device would use the electricity to desalinate seawater and pass the fresh water to electrolyzers to produce hydrogen. Another device would filter nitrogen from the sky. Reverse fuel cells would knit the two together into ammonia for loading on the tankers—a bounty of energy from the sun, air, and sea.
Liquid sunshine, Science, 13 Jul 2018: Vol. 361, Issue 6398, pp. 120-123.