Now ,

Hence substituting for

(8)

τ_w is called the weight time similar to space-time τ. C_A and ‘a' vary with time.

Substituting, in equation (8)

Plotting versus ‘t' gives a straight line of slope of -k_d and intercept In (kτ_w)

Fig. 1. Plot to determine the rate constant and the deactivation rate constant for a reaction over deactivating catalyst. ( For mixed reactor, constant flow and independent deactivation)