When you think of ammonia, you might imagine your home cleaning supplies. If you’re a farmer, you know that ammonia is the basis for most fertilizers.
But ammonia is also a promising source of carbon-free fuel.
It’s energy dense like oil but non-polluting. Ammonia packs 20 time the energy of a lithium-ion electric battery. It is liquid at room temperatures, so it doesn’t need an enormous amount of electricity to be extra-cooled like hydrogen (another alternative to fossil fuels), which only becomes liquid at minus 423.17 degrees Fahrenheit.
Ammonia is neither as flammable nor as explosive as hydrogen or gasoline.
YOU CAN GET ISRAEL21c NEWS DELIVERED STRAIGHT TO YOUR INBOX.
SUBSCRIBE TODAY
All this makes ammonia exactly the sort of fuel alternative that should make it possible to wean ships, trucks and possibly even planes off of fossil fuels. (Passenger vehicles, other than a few exceptions like Toyota’s hydrogen-powered Mirai, are solidly on the electric battery train.)
Getting here, however, requires green production, using renewable energy sources to power the reactions. Otherwise, ammonia production is particularly polluting: Producing a ton of ammonia generates 2.5 tons of CO2.
Israeli startup Nitrofix has developed another approach.
Instead of relying on large amounts of externally generated electricity – green or otherwise – Nitrofix is working on a specialized catalyst that reduces by 90% the amount of energy needed to produce ammonia.
A renewable energy dream
Ammonia could be the next big thing in carbon-free fuel
Nitrofix cofounder and scientific adviser Prof. Ronny Neumann. Photo courtesy of Nitrofix
The catalyst was invented by chemist Prof. Ronny Neumann of the Weizmann Institute of Science. Nitrofix worked with the Weizmann’s Yeda technology transfer company to license the tech for commercialization.
Ammonia consists of one nitrogen atom and three hydrogen atoms (NH3). Nitrofix combines nitrogen from the air with hydrogen extracted from waterto make ammonia.
ADVERTISEMENT
It’s a renewable energy dream: Just mix air and water and you get a fuel as powerful as oil and the only byproduct is oxygen. That’s one reason for the company’s name.
“We ‘fix’ nitrogen,” Nitrofix CEO Ophira Melamed tells ISRAEL21c.
Nitrofix’s catalyst is “an organo-metal compound that holds the nitrogen for the reaction, thus reducing the activation energy required,” Melamed clarifies.
By “organo-metal,” Melamed means that the catalyst compound contains both organic carbons and oxides as well as some metal atoms such as iron.
Ammonia could be the next big thing in carbon-free fuel
Nitrofix CTO Meital Alon, left, and CEO Ophira Melamed. Photo courtesy of Nitrofix
Nitrofix’s approach differs from other ammonia-production methods, which require the production of hydrogen gas, rather than water, from which to extract the appropriate atoms.
Hydrogen gas has the downside of containing methane, which has a tendency to leak out of pipes. The US Environmetal Protection Agency estimates that methane has 28 to 36 times the warming potential of CO2.
Nitrofix hopes to improve on the “Haber-Bosch approach” used by most other ammonia production firms.
Haber-Bosch has two steps. The first is the production of hydrogen gas. The second is a reaction between that gas and nitrogen. Most Haber-Bosch-based facilities use fossil fuels to power the hydrogen production.
ADVERTISEMENT
“It requires high temperatures and high pressure — 300 degrees Celsius and 400 atmospheres, both of which are very energy intensive,” Melamed explains. “We’re doing it at room temperature, at 50 degrees Celsius, with 10 atmospheres of pressure.”
Ammonia as a shipping fuel
Shipping is where ammonia-as-a-fuel is already seeing some forward movement.
It makes sense: Shipping emits over one billion tons of carbon each year. If it were a country, that would make shipping the sixth-largest emitter in the world after China, the United States, India, Russia and Japan.
Ther are no ships currently running on ammonia, although Nitrofix CEO Ophira Melamed says the first vessel will launch later this year. That ship, the Kriti Future, is owned by Avin International of Greece.
ADVERTISEMENT
Another ammonia-powered ship, a 1957 tugboat docked in New York, is being retrofitted by a different ammonia startup, Amogy.
Until ammonia-based ships arrive, there are plenty of uses for green ammonia on land. Around 160 million metric tons of ammonia are used annually, 80% of it for making fertilizers.
Ammonia is also used as a refrigerant gas, for water purification and in the manufacture of plastics, explosives, textiles, pesticides, dyes and other chemicals.
Other uses for ammonia
Non-transportation industries also care about getting to carbon-zero, if mainly for the bragging rights.
