Stripping of acetone from isopropanol solutions with membrane and mesh gas-liquid contactors
Special Symposium - EPIC-1: European Process Intensification Conference - 1
EPIC-1: New Concepts (NC)
Keywords: stripping, membrane, gas liquid contactor
There has been significant research on membrane processes for the separation of volatile components from solutions. The membrane acts as a fixed interface and keeps the gas/liquid phases separated, while the transport of volatiles can take place through the membrane. Advantages membrane contactors offer over columns and other conventional mass transfer equipment include relatively large interfacial area between the two phases, no fluid-fluid dispersion, while flooding, foaming, and emulsion formation can be avoided, and scale up can be facilitated. On the other hand, membrane contactors have also disadvantages: the membrane introduces an additional resistance to mass transfer, they are subject to fouling and phase breakthrough between the two phases which can result to reduced performance.
In this work, the issue of mass transfer resistance that the membrane introduces is addressed. More specifically, thin stainless steel plates with small thickness containing openings manufactured by laser machining (L-mesh) or photochemical etching (I-mesh) are studied. For comparison metal (Mott) and Teflon membranes (PTFE) are also employed. For pressure difference between phases of 30mm H2O, the I-mesh gives the best performance for acetone stripping. About 65% of the acetone can be removed with it for a liquid residence time of 2.4 min, while only 23~33% of acetone is removed using the other contactors. The improved mass transfer resistance is due primarily to its small thickness (50 microns). However, due to the large opening size of the I-mesh contactor (75 microns) the pressure difference between phases has to be carefully controlled to avoid breakthrough of one phase into the other.
Presented Thursday 20, 15:20 to 15:40, in session EPIC-1: New Concepts (NC).
