In a paper in the journal Fuel, a team from India reports on their investigation of he potential of ammonia as a secondary fuel in diesel engines.

A single-cylinder diesel engine was utilized to assess engine performance and combustion characteristics using ammonia gaseous blends. Ammonia was combined with biogas to mitigate its corrosive effects and compensate for its lower heating value.

Diesel was mixed with biogas in compositions of 10 LPM, 20 LPM and 30 LPM, and tested under engine loads of 25%, 50%, 75%, and 100%. The blend with the highest ammonia concentration exhibited the largest heat release rate, highlighting a strong correlation between ammonia content and heat release levels.

The team attributed this to the premixed combustion phase and the accelerated flame speed associated with ammonia.

An increase in ammonia content resulted in higher brake thermal efficiency and reduced brake specific fuel consumption.

All ammonia-inclusive blends showed a decrease in hydrocarbon and carbon monoxide emissions, with the lowest emissions observed in the B30B3 blend. However, the high flammability of biogas in the B30B3 blend, compared to diesel, and enhanced fuel atomization, led to increased nitrogen oxide formation.

The results clearly indicate that combination of ammonia along with the biogas enhances the combustion and reduces greenhouse gas emissions. Findings of this study provides valuable insights into the use of ammonia as a sustainable alternative in diesel engines, offering a improved balance between combustion efficiency and environmental impact.

—Ramar et al.

Resources

• Kumarasubramanian Ramar, Ganesan Subbiah, Hesham S. Almoallim (2024) “Ammonia-enriched biogas as an alternative fuel in diesel engines: Combustion, performance and emission analysis,” Fuel, Volume 369, doi: 10.1016/j.fuel.2024.131755.