title: A comparison of the Wheeler-Jonas model and the linear driving force at constant-pattern model for the prediction of the service time of activated carbon cartridges.
abstract: The linear driving force (LDF) model is applied to predict the service life of activated carbon cartridges. It is compared with the currently used Wheeler-Jonas equation, which results from a model of chemical reaction kinetics. The LDF model is based on a mass transfer model of adsorbate into the particle. The two models are studied in constant-pattern conditions. The properties of the two models are first clarified and then compared. It is shown that the Wheeler-Jonas equation leads to symmetrical breakthrough curves, whereas the constant-pattern LDF equation results in asymmetrical curves. Thus, the curvature of the isotherm has no influence on the shape of the Wheeler-Jonas curve. For the LDF breakthrough curve, it is shown that the asymmetry increases with the curvature of the isotherm. Wheeler-Jonas can be used with a Dubinin-Raduskevitch isotherm, whereas the LDF model analytical solution is valid for a Langmuir isotherm only. The LDF model can be used with the DR isotherm, but a numerical solution is required. At very low concentrations where the isotherm is linear, the constant pattern no longer exists and both models fail. The Dubinin-Raduskevitch isotherm must be fitted with a Langmuir isotherm to use the analytical solution of the LDF model.
authors.affiliation: Laboratoire Réactions et Génie des Procédés CNRS 1, rue Grandville 54001 Nancy, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Grévillot
authors.forename: Stéphanie
authors.initials: S
authors.lastname: Marsteau
authors.forename: Cécile
authors.initials: C
authors.lastname: Vallières
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D007700:Kinetics; D008422:Materials Testing; D008956:Models, Chemical; D011237:Predictive Value of Tests; D012134:Respiratory Protective Devices / Q000592:standards*; D013997:Time Factors
chemical_list: D002606:Charcoal