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 .