Hydrogen Production by Steam Reforming of Commercially Available LPG in UAE

Steam reforming of commercially available LPG using Ru/Al2O3 and Ni/Al2O3 catalysts has been studied at temperatures between 573 and 773 K. Ru/Al2O3 catalyst showed higher rates of reaction and lower activation energies of the three main components of LPG, compared with Ni/Al2O3. However, Ni/Al2O3 catalyst showed a better H-2:CH4 selectivity. The activation energy of n-butane was the lowest over Ru/Al2O3, whereas over Ni/Al2O3, propane had the lowest activation energy. The activation energy of i-butane was always the highest over both catalysts, which suggests that both catalysts performed better with unbranched molecules. A slight increase in activation energy was observed, when each component of the LPG mixture was studied separately as a pure gas, compared with being mixed in LPG. At a constant temperature of 773 K, hydrogen production yield and H-2:CH4 selectivity were determined using Ru/Al2O3 at different steam: carbon (S:C) ratios and LPG flow rates. It was found that the yield and selectivity increased with the increase in S: C ratio and the decrease in the flow rate. The highest yield of 0.64 was achieved using S: C ratio of 6.5 and a LPG flow rate of 50mL min(-1). The work provides valuable information on steam reforming of pure components of LPG, compared with when they are in the mixture. The comparison is done using conventional steam reforming catalyst, Ni/Al2O3, and compared with Ru/Al2O3. The observed trends and variations in reaction rates, in pure and mixed gases, indicated that the mechanism of steam reforming of a hydrocarbon mixture depends on its composition.