MASS-TRANSFER RESISTANCES IN HOLLOW-FIBER PERVAPORATION

The pervaporation of chloroform-water solutions across polysulfone hol low fibers thinly coated with polydimethylsiloxane (PDMS) is largely c ontrolled by mass transfer in the feed. The mass transfer coefficients in the feed agree closely with literature correlations for cross flow on the shell side of baffled modules. They do not agree with literatu re correlations for lumen flow, probably because the flows here are at Reynolds numbers in the transition region. The mass transfer resistan ce of the coated fiber itself is consistent with the known properties of PDMS. The mass transfer resistances on the permeate side are neglig ible. (C) 1998 Elsevier Science B.V.