ABSTRACT
In many processes, a gas-phase reactant dissolves in a liquid to react with the liquid or with other substances present in the solution. Examples of partial oxidation of organic liquids are the oxidation of cyclohexane to cyclohexanone and the oxidation of p-xylene to terephthalic acid, processes that are carried out by bubbling air through the liquid in a stirred tank. Reactions of oxygen in aqueous solution include aerobic fermentations and destruction of organic contaminants in polluted water. Reactions of other gases such as chlorine, hydrogen, carbon monoxide, and ethylene, with organic compounds are often carried out in the liquid phase, and in all these examples the gas must dissolve before reaction takes place. The dissolving of a gaseous reactant is a mass transfer step that may have a slight or a large effect on the rate of reaction, depending on the gas solubility, the mass transfer coefficient, and the intrinsic kinetics of the reaction.
