Hydrotreating Residue Deactivation Kinetics and Metal Deposition

Introducing a fractional type of time-varying activity coefficient, the residue hydrotreating catalyst deactivation kinetic model was established. On the basis of the operating conditions and data collected from a commercial residue hydrotreating units, the kinetic parameters such as the reaction order, activation energy, reaction rate constant, and the activity coefficient were estimated, and the time-varying equations of the activity coefficient were obtained. By timely measuring the metal content of inlet and outlet flows of the catalytic bed, and through its material balance of each period, the amount of metal deposition accumulating on the catalyst was determined, The relationship between the metal deposition and the activity coefficient was analyzed and discussed. It was found that the amount of metal deposition was linearly related with the activity coefficient in the stable operation period, this feature indicated that the reaction rate was controlled by pore diffusion in this stage. Combining the empirical equations correlated to metal deposition mount and activity coefficient with real running time, the operation period of the commercial units could be predicted.