Heat and Mass Transfer in Exothermic Gas Absorption

Abstract

Gas absorption and any associated chemical reaction is always accompanied by the simultaneous release of heat of solution and heat of reaction. The micro-scale phenomena taking place close to the interface therefore involve the generation and diffusion of heat as well as the diffusion and reaction of material species. In developing a fundamental appreciation of simultaneous mass and heat transfer in gasliquid reactions it is important for the heat effects to be incorporated into the analysis of diffusion and reaction because the rates and pathways of chemical reactions are usually enormously sensitive to temperature. In particular, for the case of gasliquid reactor performance, if the heat effects are such that the mass transfer with reaction zone adjacent to the interface is at a temperature significantly different from the bulk, the yield and the selectivity performance will be erroneously interpreted if reaction is assumed to take place at the bulk liquid temperature. In consequence, the basic conceptual design of a commercial gasliquid reactor could incorporate fallacious reasoning leading to inefficient operation at sub-optimal yield.