A bubble column was investigated as a method to achieve a desired and controllable rate of evaporation of a pharmaceutical solution. Applying a thermodynamic model to predict the rate of evaporation, all predicted values were observed to have accuracies within the bounds of instrumentation errors (<5% absolute). The thermodynamic model accounted for the measured effect of reduced vapor pressure caused by the dissolved solids as a function of their concentration. A general method to obtain accurate measurement of this effect is introduced and applied, improving the accuracy of model predictions. Predicting the rate of evaporation using the developed model, consistent and repeatable evaporation rates ranging from 0.7 -6.9 g/min were achieved, and errors between predicted rates and experimental ranged from 0.219% to 4.19% absolute. This demonstrates a more controllable and flexible alternative to the evaporation of process streams compared to boiling. The column was configured in a continuous mode and coupled to a downstream crystallizer (MSMPR). Using the column as a controllable concentrator, the concentration of a dilute feed stream of paracetamol in methanol was increased in a single equilibrium stage. The column demonstrated the ability to concentrate the solution in flow by 179%, delivering an output of 2 mL/min to the MSMPR. The MSMPR achieved steady-state of control, measured by offline This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process which may lead to differences between this version and the Version of Record. Please cite this article as