A Mathematical model has been developed for predicting the outlet gas composition of a fluidized bed reactor in which the oxychlorination of ethylene process taking place. In the present work, a mathematical model is developed for predicting the outlet concentration and conversion of ethylene in the first reactor, which is fluidized bed reactor. A three phase fluidization has been assumed in which bubble phase, cloud-wake phase and emulsion phase exist.Further the model predicts the variation of concentration of gaseous species along with bed height. The model results have been compared with...