Reaction-Diffusion Model of Multi-Component Parallel Reaction in Methanol Synthesis Catalyst and Optimization of the Size of Catalyst Particle

In this paper, a multi-component reaction-diffusion model of parallel reaction is developed in methanol synthesis catalyst. The orthogonal collocation method as well as Broyden quasi-Newton method is applied to solving the model and the model is validated by global kinetics data with satisfactory results. The internal effectiveness factor of different size of catalyst particles is obtained, and smaller particle is favor for improving the catalytic efficiency. A two-dimensional model is set up to simulate industrial methanol synthesis reactor. The effect of particle size on the methanol yield is investigated by comparing different capacity of reactor packed with different size of catalyst. The methanol yield is increasing with decreased particle size, but smaller catalyst can lead to higher pressure drop of reactor and increase the energy consumption. An optimized catalyst is proposed by considering both catalyst activity and power consumption. The method developed can provide supportive information for catalyst modification and reactor design.