Hydrodynamic simulation of methanol synthesis in gas–liquid slurry bubble column reactors

Abstract

A transient, two-dimensional hydrodynamic model for the production of methanol from syn-gas in an Air Products/DOE LaPorte slurry bubble column reactor was developed. The model predicts downflow of catalyst at the walls and oscillatory particle and gas flow at the center, with a frequency of about 0.7 H. The computed temperature variation in the reactor with heat exchangers was only about 5°K, indicating good thermal management. The computed slurry height, the gas holdup and the rate of methanol production agree with LaPorte's reported data. Unlike the previous models in the literature, this model computes the gas and the particle holdups and the particle rheology. The only adjustable parameter in the model is the effective particle restitution coefficient. It gives values of granular temperature, random particle oscillating velocities, that agree with measurements in a laboratory slurry bubble column containing the methanol catalyst that was built to approximate the La Porte reactor. The computed turbulent kinetic energy or the granular temperature agrees with similar measurements at Ohio State University in a bubble column extrapolated to no particles.