MASX-MADS process

In the MASX/MADS process, the use of membrane modules avoids any capacity or scaleup difficulties. Capacity is increased by adding more modules. Scaleup is easy because the well-defined interfacial area allows excellent characterization of the volumetric mass transfer rates. The modules also allow independent variation of the flow rates without flooding, as in conventional solvent extraction. Density differences between the solvent and extraction feed are not required for phase separation because the membrane separates the phases (22). Unlike... 

Figure L Flow diagram for the MASX/MADS process.

Where K a is the mass transfer coefficient, C is the VOC concentration in the solvent in equilibrium with the vapor phase, C is the actual solvent VOC concentration, and J is the flux of the VOC. Raising the temperature will cause C to approach zero. For the dilute VOC in the solvent, small values of C cause the flux to approach zero and separation does not occur. By using membranes with their large area to volume ratio, the mass transfer coefficient can be increased by an order of magnitude or more compare to a conventional packed column (33). This increase in area will enhance flux despite small values of C, thus making the separation more feasible. The VLE data needed to evaluate the MASX/MADS process are currently being collected. It is expected that this process wiU perform well. 

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