Waterless wool cleaning process with supercritical carbon dioxide: extractor modeling and optimisation

Publisher Summary This chapter elucidates the waterless wool cleaning process with supercritical carbon dioxide, along with extractor modeling and optimization. Describing a rigorous extraction process model, a rigorous process model is used to calculate the operating time for the semi-batch extraction of raw wool. The wool is loaded into the extractor and compressed either mechanically or by the action of the pressure differential across the bed. In either case, a model relating the compression stress to the mass balance equations is necessary. To develop such a model, the following assumptions are made: (a) dissolution of the lanolin and wax materials deposited on the wool fibers occurs at the fiber-fluid interface by mass transfer; fibers are distributed at random in the bed; (b) operation is isothermal; (c) the concentration of lanolin at the fiber surface equals its saturation value in the solvent; (d) wool fibers are assumed to be thin cylinders of constant diameter; (e) while axial dispersion in the bed is considered in the model, transverse dispersion is assumed to be extremely fast; and (f) the time for the pressure drop to establish is small compared with the extraction time so that the mechanical energy equation is directly written for the steady state.