Mass Transfer in the Liquid Phase Methanol Synthesis Process

The mass transfer characteristics of the liquid phase methanol synthesis process were experimentally investigated using a one-liter, mechanically agitated slurry reactor. The CuO/ZnO/Al₂O₃ catalyst was crushed to -140 mesh and suspended in an inert mineral oil (Witco # 40). The catalyst loading was varied within limits of experimental feasibility. The effects of temperature, pressure, level of oil, impeller speed, and gas flow rate on the overall gas-liquid mass transfer coefficient KLiaB were studied The results obtained using a two-level, half-fractional factorial design of experiments indicated that the impeller speed, feed flow rate, and temperature had significant effects on the mass transfer coefficient at the experimental conditions examined. Correlations were developed for the Sherwood number based on the Reynolds number, the Schmidt number, the reciprocal gas flow number, the gas-liquid viscosity ratio, and the dimensionless temperature. A simplified power-law type approach was also used to correlate the overall gas-liquid mass transfer coefficient with the impeller speed, gas flow rate, and dimensionless temperature