May the Froth be with you
Since the inception in 2009 of Westec Environmental Solutions LLC, the design goals for the Regenerative Froth Contactor has been to develop a contactor with a high mass transfer rate that could produce and manage solids in situ enabling the use of precipitating solvents with a simple process flow.
In order to achieve this goal the internals that typically forms the surface area of a packed bed contactor were replaced with a “froth” formed by the internals of the RFC.
To form the froth the RFC takes advantage of solvent pulsing that occurs in downflow co-current systems.
Pulsing in downflow co-current systems has been widely studied but all of this work was involving reactor technology and not absorber technology.
In addition, no attempt had been made to optimize packing used to develop the solvent pulses.
The work at WES was the first-time internals have been developed specifically to enhance the pulsing phenomena while minimizing the surface area of the actual internals themselves.
The gas-liquid interface of the RFC also has a high interface replenishment rate.
The pulsing flow regime continuously reforms the gas-liquid interface as the multiphase flow advances through the absorber column.
The turbulent flow creates a greater interfacial area, increases the rate of mass transfer per unit volume, continually disperses the solute throughout the solution, and minimizes liquid phase and gas phase. The thin-walled bubble structure eliminates the diffusion-limited mass transfer problem found when high viscosity solvents are used in conventional structured- or random-packing columns.