Processes and apparatus are disclosed for recovery of purified products
from a fluid mixture by means of integrated perm-selective separations
with purified product recovery operations. More particularly, integrated
processes of the invention comprise separations by means of one or more
devices using polymeric membranes coupled with recovery of purified
products by means of fractional crystallization and/or selective
sorption. Processes of the invention are particularly useful for recovery
of a very pure aromatic isomer when processing aromatic starting
materials, for example, a pure para-xylene product from liquid mixtures
even containing ethylbenzene as well as the three xylene isomers.