THERMALLY SAFE OPERATION OF A SEMIBATCH REACTOR FOR LIQUID LIQUID REACTIONS - SLOW REACTIONS

Thermally safe operation of a semibatch reactor (SBR) implies that conditions leading to large accumulation of unconverted reactants are avoided. The various thermal responses of a cooled SBR, in which an exothermic liquid-liquid reaction takes place, can be precisely defined and represented in a diagram with the kinetics, cooling capacity, and potential temperature rise as the key factors. Reactions of the type “slow, taking place in the dispersed phase,” are found to be more prone to accumulation and dangerous temperature runaway than those of the type “slow, taking place in the continuous phase”. Reaction systems at the brink of dangerous accumulation have a few characteristic features in common such as heat production versus time, conversion at the end of the supply period, amount of accumulated reactants, and adiabatic reaction behavior. Laboratory methods, based on these characteristic features, for the early recognition of such reaction systems can be developed. © 1990, American Chemical Society. All rights reserved.