Mahmoud Gorji - Dept. of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
Mohammad Kazemeini - Dept. of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran
Ramin Bozorgmehry - Dept. of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran

The present research was concerned with two fronts including experimental and theoretical. The experimental results obtained in liquid phase hydrogenation of NDMA in a semi-batch stirred tank reactor indicated that at low impeller speeds, kinetics of reaction was not controlling, rather the hydrodynamics of the system and specially gas hold up distribution was the rate determining step. The present research was concerned with the improvement of gas hold up distribution, hence the overall reaction rate in the mentioned mixing controlling system. Computational Fluid Dynamics (CFD) is a useful tool to investigate effects of the hydrodynamics and gas hold up distribution in the improvement of the reactor performance in such a case. For this purpose two fluid (Eulerian-Eulerian) model and finite volume method, along with standard k − ε model to address turbulent behavior of both phase, have been used. Results indicated that there should be an optimum value for hydrogen inlet velocity to exhibit a desirable gas distribution in the liquid.

NDMA, liquid phase hydrogenation, mixing, hydrodynamics, CFD