Engineering Study On Thin-Wall Through-hole Methanation Catalyst

The method and experimental setup for studying equivalent diameter of irregular particles were built to measure thin-wall through-hole methanation catalysts. The equivalent diameter can be applied for studying on diffusion-reaction model and thermal conductivity coefficient.ZrO2/Al2O3 Ni-based catalyst was prepared by impregnation method and the influence of operating conditions was investigated under the condition of temperature 340-430℃, pressure 0.1-2.5 MPa and space velocity 8000 mL/(g-h). Based on CO hydrogen assisted dissociation mechanism, the hyperbolic intrinsic kinetics model was derived in form of the reactant fugacity. By orthogonal design method, parameters of kinetics model were estimated through the max inherit optimization. Residual analysis and statistical test indicated that the intrinsic kinetic model was reliable. Based on intrinsic kinetic model, diffusion-reaction model was developed to calculate internal effectiveness factor. The diffusion-reaction model was verified by the global reaction rate obtained in a gradientless reactor. Results show lower temperature and higher pressure were favorable to increase the internal effectiveness factor.The temperature distribution in fixed-bed reactor packed with thin-wall through-hole catalysts was measured. A two-dimensional heat transfer model was built to describe heat transfer in the fixed-bed reactor. Orthogonal collocation method was adopted to solve the equations and then effective radial thermal conductivity and wall heat transfer coefficient were obtained. Effective radial thermal conductivity and wall heat transfer coefficient were related by particle Reynolds numbers.