As a world first, scientists from Monash University have developed a new, environmentally friendly process that could advance the future production of green ammonia.
Ammonia (NH3) is a globally important raw material for fertilizer production in order to maintain food production. It is currently produced from natural gas using a metal-catalyzed reaction between nitrogen gas and hydrogen using an established technology, the Haber-Bosch process.
The production of every ton of ammonia contributes to the emission of around 1.9 tons of carbon dioxide and accounts for around 1.8 percent of global CO2 emissions.
A team of scientists from Monash University led by Professor Doug MacFarlane, Dr. Bryan Suryanto and Dr. Alexandr Simonov discovered a process based on phosphonium salts that represents a breakthrough in overcoming this carbon-intensive problem.
The research published in the journal science, unleashes the potential to produce renewable ammonia and fertilizers in reactors as small as a refrigerator that could be introduced at the individual farm or community level.
One of the direct, carbon-free ammonia synthesis methods currently being investigated is the electrochemical nitrogen reduction reaction, which can produce ammonia at room temperature and pressures from nothing other than air, water and renewable energy.
But previous attempts to do this work have so far found very low levels of ammonia, in part because of the need for “sacrificial” sources for protons, said Dr. Suryanto from the Monash School of Chemistry.
“In our study, we found that a phosphonium salt can be used as a ‘proton shuttle’ to resolve this limitation,” said Dr. Suryanto.
“In 2019, the total global production of ammonia reached 150 million tons per year, making it the second most widely produced chemical raw material in the world. As the world population increases, the demand for ammonia will reach 350 million tons per year by 2050. Due to the increasing interest in its use as an energy carrier or fuel, an additional increase in the demand for ammonia is expected.
“The Haber-Bosch process currently used to produce ammonia is extremely carbon-intensive. In addition, it requires high temperatures and pressures and is only feasible in large reactors in large industrial plants.
“Our study has enabled us to produce ammonia at room temperature at high, practical rates and efficiencies.”
Chemist Professor MacFarlane believes that using climate-neutral production technologies could also use ammonia as a fuel and replace fossil fuels by 2050.
Ammonia is already widely recognized as the ideal carbon-free fuel for future international shipping, a market that is expected to be worth more than $ 150 billion by 2025.
“The technology we have developed also opens up a wide range of possibilities for future scaling up to very large production facilities for export that are connected to dedicated solar and wind parks,” said Professor MacFarlane.
“These could be placed in ideal locations for generating renewable energies such as the northern areas of Western Australia.
“Our discoveries have been licensed to a new Monash spin-out called Jupiter Ionics P / L that will scale up the process to demonstrate operation in commercial applications.”
The Dean of the Monash University Faculty of Science, Professor Jordan Nash, said the study was an important contribution to the development of a sustainable fuel for the future.
“I commend the outstanding work of our world-class researchers, whose discoveries will help Australia position itself as a leader in the ammonia economy,” he said.