KINETICS OF CHLORINATION AND CARBOCHLORINATION OF MOLYBDENUM TRIOXIDE

Kinetics of chlorination of MoO3 with Cl-2-air, Cl-2-N-2, and Cl-2-CO-N-2 gas mixtures have been studied by nonisothermal and isothermal thermogravimetric measurements, between ambient temperature and 900 degrees C. Between 500 degrees C and 700 degrees C, the chlorination reaction of MoO, with Cl-2-N-2 gas mixture has an apparent activation energy of about 165 kJ/mole, reflecting that a chemical reaction is the rate-controlling step. The reaction order with respect to Cl-2 partial pressure is about 0.75. The apparent activation energy for carbochlorination with Cl-2-CO-N-2 gas mixture is about 83 kJ/mole, between 400 degrees C and 650 degrees C. The carbochlorination of MoO, was controlled by the chemical reaction, probably affected by the pore diffusion regime. The maximum reaction rate is obtained by using a Cl-2-CO-N-2 gas mixture, having a Cl-2/CO volume ratio equal to about 1. The total apparent reaction order with respect to Cl-2 + CO in Cl-2-CO-N-2 gas mixture is about 1.5 for a Cl-2/CO ratio equal to 1.