(387b) Pervaporation of High Boiling Point Organic Compounds (HBOCs) with Composite PDMS Membrane

High Boiling Point Organic Compounds (HBOCs) are
defined as those organic compounds with boiling point over water (100^oC).
It is a challenging problem to separate HBOCs from their mixtures with water.
Three HBOCs, propargyl alcohol, butanol and pyridine, were selected as the
experimental samples for observing their separation behaviors from water
mixtures by PDMS membrane pervaporation. These HBOCs could preferentially
permeate the PDMS membrane and were selectively extracted from the mixtures through
the membrane. The experimental tests showed that the permeation flux of
propargyl alcohol, butanol and pyridine was 243.24, 976.5 and 904.70 gm^-2h^-1, with the corresponding selectivity of 3.78, 29 and 26, respectively. The effects of feed flow rate, feed concentration and temperature on
the separation behaviors were examined. By comparison with distillation that
separates different components in a mixture on the basis of boiling point, the
membrane pervaporation seems to behave a 'reverse direction' selective
separation for the HBOCs. For those aqueous mixtures with tiny content of
HBOCs, the 'reverse selective separation' by membrane pervaporation should be
considered as a promising and effective technology.