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A simple procedure has been developed for evaluating the equivalent isothermal temperature for nonisothermal reactors. Reaction-rate constants determined from a kinetic study are averaged by a simplified integration method; the average rate constant defines the equivalent isothermal temperature. Use of this equivalent temperature permits direct comparison of experiments carried out in reactors having widely different temperature profiles.Temperature so strongly influences the rate of chemical reaction that in any reaction study temperature must be accurately known. Ideally such studies are carried out in isothermal systems where the reaction temperature is known without question. When the reaction absorbs or evolves much heat, however, isothermal operation a t practical conversion levels is almost impossible. Different parts of the reacting system a r e at widely different temperatures, and determining average reaction temperature becomes a real problem.Endothermic reactions, for example, are often carried out commercially in a number of adiabatic reactors in series. A large variation in temperature exists in each reactor. Figure 1 shows a temperature profile typical of such a system. Pilot-plant studies attempt to duplicate the commercial operation and therefore operate with the same type of temperature profile. In smaller scale reactors it is extremely difficult to carry out reactions with large heat effects either adiabatically or isothermally. Small-scale reactors operate with quasiisothermal profiles such as t h e profile shown in Figure 2. I n this example temperature drops rapidly in the inlet end of the bed because t h e reaction absorbs heat faster than it can be supplied through the reactor walls. This situation is reversed as the reaction slows down, and temperature rises in the exit end of the bed. Changes in feed composition, reaction conditions, size and location of reactor heaters, and dilution of the catalyst bed with inert material obviously make a wide variety of temperat u r e profiles possible.Researchers are thus confronted with the problem of comparing experiments performed in reactors that have widely different temperature profiles. Direct comparison is possible only if each temperature profile can be expressed by a single equivalent temperature -the equivalent isothermal temperature. This important concept of equivalent temperature has been recognized but rarely used. Previous authors ( I , , ? ) developed algebraic solutions f o r the equivalent temperature f o r eases i n which temperature can be related algebraically t o reaction time or to distance through the catalyst bed. However, these solutions are complex. Calculating equivalent temperature f o r anything more than a handful of experiments is so time consuming t h a t the concept has been little used. This paper presents a simple method for calculating equivalent temperatures that can be readily applied to a large number of experiments. EQUIVALENT ISONTHERMAL TEMPERATUREA reaction-rate equation can usually be expressed in the foll...