Binary Solvent Swap Processing in a Bubble Column in Batch and Continuous Modes.

Area of Science:

• Chemical Engineering
• Separation Processes
• Thermodynamics

Background:

• Pharmaceutical manufacturing often requires efficient solvent exchange processes.
• Traditional solvent swap methods can be energy-intensive or require high pressures.
• Bubble column technology offers a potential alternative for low-temperature operations.

Purpose of the Study:

• To investigate a lab-scale bubble column as a method for low-temperature binary solvent swapping.
• To compare experimental solvent evaporation rates with predictions from vapor-liquid equilibrium (VLE) modeling.
• To evaluate the performance of both batch and continuous bubble column configurations.

Main Methods:

• Utilized a lab-scale bubble column apparatus for solvent evaporation.
• Employed first-principles vapor-liquid equilibrium (VLE) thermodynamic modeling for prediction.
• Conducted experiments in both batch and continuous modes under atmospheric pressure.
• Measured evaporation rates and solution concentration changes during operation.

Main Results:

• Achieved evaporation rates up to 5 g/min in batch mode at 2.5 L/min gas flow.
• Attained 99 mol % purity of the desired solvent within three cycles from a 50:50 mixture.
• VLE modeling accurately predicted evaporation rate profiles and concentration changes (<5% error).
• Continuous process modeling successfully predicted steady-state operation for various conditions.

Conclusions:

• Bubble columns are a viable alternative for low-temperature binary solvent swaps in pharmaceutical processing.
• VLE thermodynamic modeling provides accurate predictions for bubble column solvent swap performance.
• The developed model can reliably represent evaporation rates and concentration dynamics.