Effect of recycle-barrier location on membrane extraction in a parallel-flow rectangular module with internal reflux

The influence of recycle-barrier location on membrane extraction through a parallel-flow rectangular module with internal reflux has been investigated. The recycle barrier is placed in the raffinate phase to divide the flow channel into an operating subchannel and a reflux subchannel and thus, there are concurrent flow in one subchannel and countercurrent flow in another subchannel. It was found that the larger part of mass-transfer area for countercurrent-flow channel, as well as the smaller part of mass-transfer area for concurrent-flow channel, is beneficial to total mass-transfer rate. It was also noted that with the recycle-barrier location moving gradually from the centerline of the raffinate phase to create larger mass-transfer area for countercurrent-flow channel, and to decrease mass-transfer area for concurrent-flow channel, the same performance can be achieved with reducing the reflux ratio.