Method of selecting operation of a fluid-bed reactor and apparatus for

Abstract

A method is disclosed for using a pendulum viscometer having damped torsional oscillations, in a laboratory catalytic fluid-bed reactor, to monitor a propensity to stick which is exhibited by certain supported catalysts. A fluid-bed of such catalysts has been found to become suddenly more sticky just before a point at which a change in pressure drop across the fluid-bed can be measured due to a process 'upset'. At this point ('the inversion point'), the upset is usually irremediable. The method includes correlating data on catalyst stickiness from a laboratory reactor operating at atmospheric pressure, with an expected level of catalyst stickiness in a commercial reactor operating at elevated pressure. A pendulum viscometer and related auxiliary apparatus is disclosed for magnetically and electrically measuring and recording the rate at which the pendulum's torsional oscillations are damped. Frequent measurements are made during normal operation of the fluid-bed to determine its stickiness (as evidenced by the rate at which the pendulum's torsional oscillations are damped) relative to the stickiness at the inversion point. Operation of the fluid-bed under conditions for which measured rates of damping are predeterminedly lower than the rate near the inversion point, assures operation of the fluid-bed reactor at maximum efficiency.