Investigation of Hydrogen Production via Steam Methane Reforming Process Using Nickel Catalyst at Medium Temperatures

In this study, hydrogen production by steam reforming of methane has been investigated. Due to its wide applications and important role as a future fuel, hydrogen is a valuable material. Steam reforming of methane is one of the most common and the most important hydrogen production processes which are carried out industrially at 700-900°C. High temperatures can cause problems; such as, sintering of catalysts, rising of costs, coke formation on the catalyst, and increasing safety concerns. In this study, prevalent catalyst of this process (Ni/Al2O3) is used at medium temperatures (450-650°C) to investigate the reasons for reduction in hydrogen production at these temperatures. Increasing time, increased and after a specific time sharply decreased the methane conversion. This sharp decline in methane conversion occurred after 210 min at 600°C and 275 min at 650°C. The peaks in XRD test indicate oxidation of catalyst during the process. In the stable time of catalyst at 650°C, methane conversion and hydrogen mole fraction were 99% and 80%, respectively. Rising steam methane ratio in the range 2.5-6 increased the methane conversion and hydrogen mole fraction and decreased the selectivity of CO. At medium temperatures, nickel can produce hydrogen by steam reforming of methane, but due to deactivation of catalyst, this process cannot be carried out continuously.