Alumina particle size effect on H2 production from ammonia decomposition by DBD plasma

Abstract

The present study investigates the alumina particle size effect on hydrogen production from ammonia decomposition by dielectric barrier discharge plasma (DBD). Two different alumina particle diameters of 1 mm and 2 mm were used as a catalyst activation material. A low NH3 concentration of 0.5% was fed into the catalytic reactor at flow rates range of 0.1-1 L/min and dielectric barrier discharge plasma (DBD) voltage range of 12–18 kV. The decomposed gas samples were collected and measured by gas chromatography (GC) for both experiments. It was found that the hydrogen concentration results of plasma-alumina particle size 1 mm were higher than that obtained from alumina catalyst particle size of 2 mm. also, the conversion rate was determined at different applied voltage and flow rates for both alumina catalytic systems. The maximum conversion rates were 83.19, 80.35% at Al2O3 particle diameter of 1 mm, and 2 mm, respectively. Also, the maximum energy efficiency results of NH3 decomposition using alumina particle size of 1 mm and 2 mm were 0.29 and 0.225% which obtained at NH3 flow rate of 1, and 0.5 L/min, respectively. It can be concluded that the activation surface area is influenced by the catalyst material particle size hence the H2 production from the NH3 decomposition process.