Researchers examine promise of accelerated ammonia synthesis for renewable energy conversion

A research initiative undertaken by researchers at Hiroshima University divulges a method to fabricate ammonia from its constituent elements of nitrogen and hydrogen at surrounding pressure.

The study published in the Journal of Physical Chemistry C showcases a process that displays potential to be used in renewable energy transfer and storage, which depends on a dispersed and fluctuating network of resources such as wind and sun.

The final objective of the work is to establish small-scale ammonia production process for effective utilization of renewable energy, stated the author of the study.

In fact, recently, ammonia has been recognized as an excellent energy vector molecule. In 1918, a German chemist received the Nobel Prize for synthesis of ammonia from its elements, which paves the way for significant role of ammonia in industrial fertilizers.

However, use of ammonia in the applications of renewable energy is limited by the processes that are available to synthesize it. The process employed in the industrial production of ammonia requires high temperature and pressure conditions that are typically not available in renewable energy storage and transport infrastructure.

The synthesis of ammonia via chemical looping method uses lithium hydride. The process starts by combining lithium hydride with molecular hydrogen at temperatures up to 500C and ambient pressures to produce a lithium imide product. Later, the reaction of lithium imide with hydrogen produces ammonia. The reaction time for synthesis of ammonia from its constituent molecules in the process is more than 1000 minutes. The speed is limited by agglomeration of products of the reaction into large particles that do not have much surface area in contact with hydrogen gas.

The practical application of the method for distributed renewable energy, the prolonged reaction that requires extreme conditions is a bottleneck to the production of ammonia.