| Actual concentration profiles in multistage extractors can be calculated by utilizing two-phase component material balances if good estimations of the mass transfer coefficients are available. A model is presented which may be used to estimate the overall mass transfer coefficients using variables which can be measured easily. The model, which utilizes mass transfer coefficients based on the inlet rather than the outlet concentration driving force, can be imbedded in a procedure for rating extraction columns to obtain the actual concentration profiles. Some multistage extraction experiments were performed using a six-stage mixer-settler; simulation of the experiments showed that the actual concentration profiles may be estimated using this method while most correlations available in literature overpredicted the rate of mass transfer. In all experiments, diethylamine was extracted from methyl isobutyl ketone into water containing 2% sodium chloride. |
