Three-dimensional computational fluid dynamics numerical model was used for modeling the MeOH synthesis in a 3-phase slurry reactor on CuO/ZnO catalyst slurry in paraffin oil. The syngas hydrodynamics and hold-up, conc. profile and velocity field of slurry in the reactor were detd. For balancing the syngas bubble flow, the population balance model was used. Gas bubble size distribution was based on Sauter diam. value. Numerical calcns. for modelling the MeOH synthesis were performed by using Setinc-Levec kinetic model with heat removal option through a cooler.