Thermal Decomposition of Methane for Production of CO<sub>x</sub> Free Hydrogen over Ni-Supported Y Zeolite Based Catalysts

Abstract

The thermo-catalytic decomposition (TCD) of methane has attracted the attention of numerous researchers’ around the world as an ideal approach for hydrogen production, which in turns, can be used as an appropriate feeding gas in fuel cells operating at low temperatures. The TCD of methane is capable to produce a valuable by–product, pure carbon, which can excessively alleviate the total cost of the process. In this study, we report TCD of methane over 30% Ni supported Y zeolite catalyst at 550 and 600 °C was conducted in a fixed bed reactor and the yield of hydrogen from the reactor was analyzed by GC. As can be observed that, the TCD of methane over Ni-supported Y zeolite showed maximum conversion (31 and 15.90 % at 600 and 550 °C, respectively) at the initial stages and on stream of reaction time, it decreased gradually; and ultimately, deactivated the catalyst completely. The cause for this is the formation of encapsulating carbon on Ni active sites which deactivates the catalyst over the course of reaction time. Hydrogen production rate, carbon accumulation (CA) and carbon formation rate (CFR) were investigated at three representative times for both temperatures. The CFR analysis showed that the growth of filamentous carbon was steady-state at the first stage and then reduced to a relic activity and it remains constant during the rest of the reaction. The descriptive dissemination of methane TCD over Ni-supported Y zeolite has been speculated in this paper.