Catalyst inventory control in an ebullated bed process

摘要

An improved method of controlling catalyst inventory in the reactor of an ebullated bed process has been discovered. Pressure differentials are measured to calculate a catalyst inventory characterization factor. This factor is calculated by means of a new algorithm. Aged catalyst is withdrawn and fresh catalyst added in an amount to reestablish the value of the factor. The catalyst to oil ratio is maintained despite changes in bed ebullation, gas and liquid holdups, oil residence time and conversion.