A groundbreaking method for producing ammonia that utilizes the distinctive properties of liquid metal could greatly reduce carbon emissions linked to the creation of this essential chemical. Ammonia plays a key role in fertilizers that help to cultivate much of our food, additionally serving as a clean energy resource for safely transporting hydrogen.
A revolutionary approach to ammonia production, utilizing the unique properties of liquid metal, has the potential to significantly reduce carbon emissions associated with the widespread manufacturing of this chemical.
Ammonia is crucial in fertilizers for agriculture, and it also contributes to clean energy by acting as a safe transport medium for hydrogen.
Nonetheless, the global ammonia production process is highly detrimental to the environment, consuming more than 2% of the world’s energy and contributing to up to 2% of global carbon emissions.
According to Dr. Karma Zuraiqi, a research fellow and the main author of the study, their environmentally friendly alternative reduces energy usage by 20% and decreases the required pressure by 98% compared to the traditional Haber-Bosch process that has been in use for over a century.
“The worldwide production of ammonia currently generates emissions equivalent to twice that of Australia. By improving this process and making it less energy-dependent, we could significantly reduce carbon emissions,” stated Zuraiqi from the School of Engineering.
Findings from the RMIT-led research, published in Nature Catalysis, demonstrate that their low-energy technique is equally effective in ammonia production by leveraging more efficient liquid metal catalysts rather than relying heavily on pressure.
“The copper and gallium we utilize are also considerably cheaper and more abundant than the precious metal ruthenium, which is currently used as a catalyst,” Zuraiqi noted. “These benefits make our innovation an exciting advancement that we are eager to further explore outside the laboratory.”
Liquid metal to the rescue
The team, which includes Professor Torben Daeneke from RMIT, is leading efforts to harness the unique characteristics of liquid metal catalysts for producing ammonia, capturing carbon, and generating energy.
A catalyst is a substance that accelerates chemical reactions without being consumed in the process.
This latest study highlighted their innovative method, which involves creating tiny liquid metal droplets made of copper and gallium—affectionately termed ‘nano planets’ due to their hardened crust, liquid outer core, and solid inner core structure—to serve as catalysts for breaking down nitrogen and hydrogen.
“Liquid metals enable us to dynamically position chemical elements, allowing everything to converge and promoting more efficient reactions, perfect for catalysis,” Daeneke explained.
“Individually, copper and gallium had been regarded as ineffective catalysts for ammonia production, yet together they perform exceptionally well.”
Tests indicated that gallium effectively disintegrated nitrogen, while copper contributed to the breakdown of hydrogen, resulting in a combination that rivals current methods at a significantly lower cost.
“We essentially discovered a way to leverage the synergy between the two metals, enhancing their individual performance,” Daeneke commented.
RMIT is spearheading the commercialization of this technology, which is jointly owned by RMIT and QUT.
Upscaling for industry
Unlike ammonia produced through the traditional Haber-Bosch method, which requires large facilities, the team’s innovative approach could be suitable for both large-scale and smaller decentralized production. This would enable small quantities to be produced cost-effectively at solar farms, significantly reducing transportation costs and emissions.
Beyond its obvious applications in fertilizer production, this technology could be crucial for the hydrogen sector and the transition away from fossil fuels.
“One effective means of making hydrogen safer and easier to transport is by converting it into ammonia,” Daeneke elaborated.
“However, if we utilize ammonia synthesized via current methods as a hydrogen carrier, it could lead to a significant rise in emissions from the hydrogen sector.”
“Our goal is to integrate our green ammonia production technology with hydrogen technologies, thus allowing for the safe global transportation of green energy with minimal losses along the way,” he added.
The upcoming objectives include scaling the technology—demonstrated thus far in laboratory conditions—and designing a system that operates at even lower pressures to enhance its practicality for a wider array of industries.
“At this point, we are truly excited about the results and eager to engage potential partners interested in scaling this technology for their own industrial applications,” he said.
This research received support from the Australian Research Council and the Australian Synchrotron (ANSTO). Molecular interaction analyses were conducted at RMIT’s advanced Microscopy and Microanalysis Facility, alongside QUT’s Central Analytical Research Facility, the Australian Synchrotron, and through the NCI Australia supercomputing facility.
