With the world’s increasing reliance on electric vehicles (EVs), the quest for sustainable transportation solutions has intensified. Among these, hydrogen has emerged as a promising contender due to its clean and efficient nature, emitting only water upon combustion. However, challenges persist in storing and transporting hydrogen, primarily due to demanding conditions.
Addressing these hurdles head-on is ammonia, a compound containing hydrogen, which has garnered attention as a potential solution. Unlike hydrogen, ammonia offers enhanced storage and transport capabilities, positioning itself as a viable alternative.
The Lithium Predicament and Ammonia’s Resurgence
The rise of EVs has been fueled by lithium-ion batteries, renowned for their high energy density and longevity. However, the limited availability of lithium and the environmental impact of its extraction pose significant challenges.
According to the International Energy Agency, the demand for lithium is projected to exceed 2.4 million metric tons by the 2030s, far outstripping the 130,000 metric tons produced in 2022. This impending shortage underscores the urgent need for alternative solutions.
Enter ammonia, a compound comprising hydrogen, which offers a cleaner and more efficient fuel source. Produced from renewable sources like solar, wind, or hydropower, ammonia provides a promising alternative to lithium.
Ammonia: Powering Engines
While ammonia isn’t readily combustible by itself and typically requires gasoline for optimal combustion, recent developments have showcased its potential as a standalone fuel. Professor Mitsuhisa Ichiyanagi and his team from Japan’s Sophia University have been at the forefront of this innovation, designing engines to run solely on ammonia, eliminating the need for gasoline.
“Although there are challenges to overcome before ammonia-fueled vehicles become a reality, this research holds promise for achieving current and future decarbonization goals,” says Prof. Ichiyanagi. “The development of ammonia-fueled engine vehicles is expected to not only reduce carbon dioxide emissions from engines but also contribute to realizing a hydrogen energy society.”
Their breakthrough lies in optimizing intake port opening conditions within the engine cylinder, crucial for achieving efficient combustion. Their research, documented in a recent study published in Energies, explores how varying intake port configurations can induce swirling flow patterns within the cylinder, boosting combustion efficiency while curbing emissions.
“Airflow within cylinders profoundly affects combustion and emissions by influencing the air–fuel mixing phenomenon,” says Prof. Ichiyanagi. “With the aim of burning only ammonia, we have basically investigated the relationship between the engine’s intake system and the flow inside cylinders.”
Swirling Flows
Swirling flow, characterized by a vortex-like motion of the air-fuel mixture, holds the key to enhanced combustion efficiency. Through meticulous experimentation with an optical single-cylinder diesel engine equipped with glass components, the researchers uncovered the transformative potential of swirling flows.
Utilizing high-speed cameras, the team observed distinct flow patterns generated by different intake port designs. While helical ports induced swirling flows from the outset, tangential ports required redirection by the cylinder walls to initiate swirling structures. Crucially, maintaining the tangential port opening above 25% facilitated the formation of swirling flows during the compression stroke, ensuring stable and consistent combustion conditions.
The implications of these findings are profound, heralding a new era of cleaner and more sustainable transportation powered by ammonia. By harnessing swirling flows, researchers aim to optimize ammonia combustion within engines, paving the way for a greener automotive landscape.
As the demand for lithium skyrockets, ammonia emerges as a beacon of hope, offering a viable alternative clean fuel for the future of transportation. With ongoing research and innovation, ammonia-powered vehicles could soon become a reality, driving us towards a more sustainable tomorrow