Engineers unveil breakthrough in cleaner ammonia production

Researchers at the University of Illinois Chicago, led by Associate Professor Meenesh Singh, have pioneered a groundbreaking method for producing ammonia that promises to significantly reduce the environmental impact of one of the world’s most commonly used chemicals. Traditionally, ammonia production is a major source of carbon emissions, second only to cement, due to the high temperatures and pressures required. Singh’s team has refined an electrochemical reaction, harmonizing lithium, nitrogen, and hydrogen atoms in a process they liken to a “symphony,” to achieve a method of ammonia synthesis that meets critical green objectives.

This novel process, dubbed lithium-mediated ammonia synthesis, utilizes nitrogen gas and a hydrogen-donating fluid, such as ethanol, in conjunction with a charged lithium electrode. The key innovation lies in the method’s ability to facilitate the reaction at lower temperatures and its regenerative nature, which restores the reactants with each cycle of ammonia production. Unlike traditional methods that demand high energy to crack nitrogen gas molecules, this approach allows nitrogen atoms to bond with lithium and subsequently combine with hydrogen to form ammonia.

The team’s findings, published in ACS Applied Materials & Interfaces, build upon previous work from Singh’s laboratory, which has been at the forefront of developing cleaner approaches to ammonia synthesis, including utilizing sunlight, wastewater, and electrified copper mesh to reduce energy consumption.

The lithium-based approach, while well-documented in organic chemistry literature, has been optimized by Singh and his colleagues to run with enhanced efficiency and selectivity, potentially allowing for economically viable production. Singh estimates that if scaled, their method could produce ammonia at approximately $450 per ton, marking a 60% cost reduction compared to existing lithium-based methods and other green alternatives.

This advancement not only promises high energy efficiency and lower costs but also addresses the challenge of selectivity, avoiding the production of large quantities of unwanted hydrogen gas that have plagued previous attempts at cleaner ammonia synthesis. The process meets the Department of Energy standards for industrial-scale ammonia production and offers the possibility of further environmental benefits by operating on electricity derived from solar panels or other renewable sources.

Moreover, this method presents a viable solution for the transportation of hydrogen fuel by using ammonia as a safe and cost-effective carrier, potentially unlocking new pathways for hydrogen fuel distribution.

In collaboration with General Ammonia Co., Singh’s team is moving towards piloting and scaling up their lithium-mediated ammonia synthesis process at a facility in the Chicago area. A patent for the process has been filed by UIC’s Office of Technology Management, signaling a significant step forward in the quest for sustainable and efficient chemical manufacturing.

Source: ScienceDaily