ROLE OF STRESS IN REACTION-ENGINEERING CATALYTIC AND NONCATALYTIC REACTIONS

In this paper we address the development of mechanical stress in catal ytic and noncatalytic reacting systems. The thermoelastic formulation is presented and discussed as it applies to several examples of practi cal importance. These include fracture of catalyst pellets due to ther mal stress, application of stresses during rapid cooling of reacted sa mples, and stress development during noncatalytic reactions in powders or particles. Stresses develop as a result of temperature gradients d ue to heat effects of the reaction, and differences in expansion coeff icients and equivalent volume of different phases. The examples cited in this review illustrate that stresses play an important role in the design of chemical reactors and may change the reaction characteristic s, in both a qualitative and quantitative way.