“…Since most oxidation processes are highly exothermic, another important physical consideration is the ease of removal of the heat of reaction, since, if there is a runaway increase of temperature, only complete combustion of the hydrocarbon will take place. To facilitate the maintenance of as nearly as possible isothermal conditions, long narrow catalyst beds are frequently used and the catalyst may also be diluted with an inert solid, perhaps using the greatest dilution at the inlet end where the partial pressures of the reactants (and hence the fluid has heat evolution) are highest (35). The catalyst must not only be in a suitable physical form to permit diffusion of reactants and products, but also chemically correct for the desired conversion Alternatively, the use of fluidized beds of catalyst material has the advantages of more efficient temperature control and of increased available surface :volume ratio of the catalyst.…”