Behavior of Exothermic Heat Generated in Synthetic Natural Gas Synthesis with Morphology of Nickel-Based Pellet-Type Catalysts

In this study, the behavior of exothermic heat generated during SNG (Synthetic Natural Gas) synthesis was investigated by evaluating the morphology of nickel-based pellet catalysts. The catalysts have a cylindrical pellet-type morphology with an external diameter of 5 mm. Additionally, single-hole pellet-type catalysts, with a hole of diameter 2 mm at the center of the pellet, were prepared for investigating the effect of the hole in pellet-type catalysts on highly exothermic reactions. The change in temperature due to the exothermic SNG synthesis reaction was measured on a single pellet and in a packed-bed catalytic reactor. The surface temperature of the pellet increased with the flow rate of reactant gas, and the increase in temperature over the single-hole pellet catalysts was higher than that over the normal pellet catalysts during SNG synthesis using single pellet catalysts. However, the temperature in a catalytic reactor packed with the single-hole pellet catalysts was lower than that when using normal pellet catalysts. From these results, it was concluded that the temperature over the catalyst surface increases as the surface area exposed to the reactant gases increases, and the packed bed in the catalytic reactor was maintained at a high temperature owing to the high catalyst packing density.