Prediction of catalyst stability in naphtha reforming

Abstract

AbstractA method to predict catalyst activity (RON) and selectivity (ηc5+, liquid yield) of naphtha‐reforming catalysts during normal operation is described. It involves performing experiments at normal operational conditions and testing accelerated deactivation. These last experiments have a severe intermediate period at lower pressure. Carbon formation is related to time and the decrease in RON and ηc5+ is related to carbon at normal operation. The accelerated deactivation produces a similar coke to the one at normal conditions for an equal amount of coke. Therefore for each time at normal conditions there is a corresponding pressure in the accelerated deactivation test. Power law‐equations fit the data well and combining them results in the following relations: P = atb; ΔNRON = cPd; ΔNηc5+ = ePf. The coefficients a, b, c, d, e and f depend on the catalyst and are calculated from four or six experiments (half at normal conditions and half accelerated deactivation tests); b, d and f bare negative. The value of pressure for the time at which it is desired to predict catalyst activity and selectivity is calculated from the first equation. This value when applied to the second and third equations gives the activity and selectivity, respectively, that the catalyst will have after time t.