The maritime industry is beginning to show significant interest in using ammonia as a "bunker fuel," a sustainable alternative to the highly polluting heavy fuel oil (HFO) currently used in ships across the world.
In recent months, a firm of naval architects and a new maritime think tank have both been evaluating ammonia as a fuel. This includes a road map for future research, and collaborations for a demonstration project that will allow them to design and build a freight ship "Powered by NH3."
One of the many encouraging announcements at the recent Power-to-Ammonia conference in Rotterdam was the news that the Korea Institute of Energy Research (KIER) has extended funding for its electrochemical ammonia synthesis research program by another three years, pushing the project forward through 2019.
KIER's research target for 2019 is significant: to demonstrate an ammonia production rate of 1x10-7 mol/s·cm2.
If the KIER team can hit this target, not only would it be ten thousand times better than their 2012 results but, according to the numbers I'll provide below, it would be the closest an electrochemical ammonia synthesis technology has come to being commercially competitive.
Module four of the ten-module research and development agenda for Japan’s Cross-Ministerial Strategic Innovation Promotion Program -- Energy Carriers is entitled “Basic Technology for Hydrogen Station Utilizing Ammonia.” The rationale for including this technology is that “high purity H2 supply system with low cost hydrogen transportation is a key issue to spread fuel cell vehicles (FCVs).”
A story published last week in the Tokyo Shimbun says that to date FCVs have not spread very far. Among the factors seen as constraints is the cost of hydrogen fueling stations (HFS). The Tokyo Shimbun story states that “according to industry officials, each station that supplies hydrogen to fuel cell vehicles runs about ¥400 million ($3.6 million) in construction costs. In order to achieve profitability, about 1,000 fuel cell vehicles are required as customers per location. Construction is not proceeding.”
So far, the players focused on FCVs do not seem to be looking to ammonia as an expedient that will help reduce the cost of HFS and thereby encourage their construction and by extension the uptake of FCVs. This appears to be a missed opportunity whose benefits may become too compelling to ignore.
On April 27 the on-line journal Science Advances published “Carbon-free H2 production from ammonia triggered at room temperature with an acidic RuO2/γ-Al2O3 catalyst.” The lead author, Katsutoshi Nagaoka, and his six co-authors are associated with the Department of Applied Chemistry at Oita University in Japan. The innovation featured in the paper could prove to be an important enabler of ammonia fuel in automotive applications.
Next month the print edition of Fuel Processing Technology will feature a paper entitled “Auto-ignition of a carbon-free aqueous ammonia/ammonium nitrate monofuel: a thermal and barometric analysis.” This title is provocative. First, what is this idea of a fuel composed of a mixture of ammonia and ammonium nitrate (AN)? If ammonia is a good fuel, is it made better with the addition of ammonium nitrate? Second, why is it aqueous? Is the presence of water a feature or a bug? Third, what is a monofuel and why is this term used when the fuel is a mixture of two molecular species? And finally, why is the paper ultimately about auto-ignition?
While Japan’s Cross-Ministerial Strategic Innovation Promotion Program (SIP) continues to evaluate liquid hydrogen (LH2), methylcyclohexane (MCH), and ammonia as hydrogen energy carriers, Japanese press reports show that the backers of liquid hydrogen and MCH are building an early lead over ammonia with hydrogen fueling stations based on their favored commodities.
At ARPA-E's recent Energy Innovation Summit in Washington, DC, Program Director Grigorii Soloveichik presented his vision for the future of transportation: hybrid electric vehicles that combine the advantages of both plug-in battery and fuel cell technologies.
This "optimal solution" will require a new generation of fuel cell that is "fast, furious, and flexible." Fast, in terms of start-up / shut-down time. Furious, in terms of energy density. And flexible, in terms of fuel choice - specifically sustainable liquid fuels, like ammonia.
The shipping industry is beginning to evaluate ammonia as a potential "bunker fuel," a carbon-free alternative to the heavy fuel oil (HFO) used in maritime transport.
International trade associations are leading the effort to decarbonize the sector, in alignment with targets set by the Paris Climate Agreement. Their immediate challenge is simple to state but hard to solve: "ambitious CO2 reduction objectives will only be achievable with alternative marine fuels which do not yet exist." In the long-term, however researchers recognize that "fuel cell-powered ships are likely to dominate, drawing their energy from fuels such as hydrogen and ammonia."
We wrote last month about the US Department of Energy funding ammonia fuel projects through ARPA-E's "REFUEL" program ("Renewable Energy to Fuels through Utilization of Energy-dense Liquids").
Although we introduced the funded projects in both the ammonia synthesis category and the ammonia fuel-use category, the REFUEL project merits further analysis as a whole because it describes a roadmap for the development of ammonia fuel systems, and identifies benchmarks for their commercial success.
Ammonia energy proponents look forward to the day when their fuel is used in internal combustion engines – but the state of this art is unsettled and it is not clear which combustion technologies will win in the end.