Analysis of Temperature-Time Data for Deactivating Catalysts

Abstract

A simple mathematical model of a single irreversible reaction with n-th order, concentration-independent catalyst deactivation is proposed. The model predicts the time-temperature relationship for the constant-conversion mode of operation and can be used to optimize temperature policy in a batch reactor. The applicability of the model to pilot-plant data from hydrocracking of gas oil and catalytic reforming of naphtha is demonstrated and the effects of process variables, such as start-of-run temperature, space velocity, and conversion level on the fouling rate are examined. The model has successfully described both the linear and exponential portions of the reaction temperature-time curves and demonstrated a linear correlation (on a logarithmic basis) between fouling rate and the work function, i.e., the product of conversion and space velocity, of the catalyst.