Energy Conversion Systems

Background ＆ Objectives

　Ammonia has a number of favorable characteristics, the primary one being its high capacity for hydrogen storage, 17.6 wt%, based on its molecular structure. The secondary merit is that ammonia itself is carbon-free at the end users, although CO2 emission on production of ammonia is dependent on the source of energy. Therefore, ammonia is the most promising of all chemicals containing hydrogen as a hydrogen carrier. However, in order to produce hydrogen from ammonia, significant energy input are required in thermal decomposition. In ammonia economy, an improvement of energy efficiency (H2-kg/kWh) is strongly desired.
　Non-catalytic hydrogen production from ammonia by using pulsed plasma may give a solution to the problem. It found that molecular ammonia was instantly decompose by electron energy from the pulsed plasma, and was converted to molecular hydrogen. Approximately 100% conversion was attained at ammonia flow rate of 0.2 L/min at applied voltage of 15 kV. However, their energy efficiency was only 14.2 mol-H2/kWh. Novel effective improvement was attempted to increase the energy efficiency, and 73.6 mol-H2/kWh was attained.

Back

Forward