A Dynamic Model for Radiotracer Determination of Solute Residence Time Distribution in Counter-Current Pulse Column Solvent Extraction Processes

A radiotracer method for the measurement of the mass holdup of a solute being processed in a counter-current pulse column using the average residence time distribution is presented and investigated by mathematical modelling. Typical solutions to the model for impulse tracer injections of the solute at the inlet show that while the number and volume of stages have a significant effect on the response of the system, the amount of backmixing has little effect, particularly for small systems. The system response to impulse tracer injections under various conditions was simulated with this model and model parameters were extracted from these simulated results by using a nonlinear least squares method to demonstrate the approach.