Question

1) What are the advantages of hollow asymmetric membrane compared to symmetric membrane ?

2) What are the advantages of hollow fiber membranes compared to other geometries ? when would one use another geometries?

3) In large membrane systems its common to have membranes cascades with membrane arranged boh in parallel and in series. What are the advantaes of this ? The arrangement after the first set of membranes in series usually will have fewer members in parallel, This has been called a christmas tree pattern. Draw this

Answer 1

1: The advantage of hollow asymmetric membrane is the mass transfer through the hollow asymmetric membrane is largely dictated by the entire skin of the poros and many folded layer rather than only of the membrane diameter in case of a symmetric membrane. This increases the mass transfer rate in comparison to the symmetric membrane and has more efficient control over the membrane selectivity.

2: Hollow fiber membranes have advantage over other geometries due to their unique morphology. These hollow fibre membranes increase the surface area due to inner foldings and hence have higher mass transfer rate in comparison to other geometries