The Wheeler-Jonas equation: a versatile tool for theprediction of carbon bed breakthrough times

摘要

The goal of this paper is to give an overview of the recent developments in the use of the Wheeler-Jonas equation. Extensivernexperimental work has been done by measuring breakthrough times of different types of activated carbon beds, underrndifferent experimental conditions, for a large variety of gases and vapours. This includes the use of activated carbon fibrernbeds, the presence of moisture on the carbon and in the air stream, non-constant flow patterns and adsorption of chemisorbedrnspecies. In all cases the applicability of the Wheeler-Jonas has been demonstrated, I.e. one can use this equation tornextrapolate single laboratory breakthrough results by simply varying the independent variables of the equation (amount ofrnadsorbent, flow rate, inlet and breakthrough concentrations). In most cases it is even possible to perform ab initiornbreakthrough calculations for a well-defined carbon bed. To achieve this new supporting equations had to be derived to allowrnthe estimation of the dependent variables, We (the equilibrium adsorption capacity) and kv (the overall mass transferrncoefficient), under different circumstances. In conclusion, the scope of the Wheeler-Jonas (or Reaction Kinetic) equationrnextends largely beyond its commonly accepted boundaries. This is primarily due to its apparent simplicity: the combinationrnof a single capacity term and an overall kinetic effect strongly enhances its applicability to different adsorptionrncircumstances. In this way it is far more potent than many of the more modern equations that require the exact knowledge ofrnseveral, not readily available, input parameters.