N. Aydogan et al., EFFECT OF OPERATING PARAMETERS ON THE SEPARATION OF SUGARS BY NANOFILTRATION, Separation science and technology, 33(12), 1998, pp. 1767-1785
Due to the complexity of fermentation mixtures, separation of solutes
and secondary substrates has a special importance. Membrane processes
such as nanofiltration may offer good alternatives for the separation
of fermentation products or recovery of substrates. For an efficient s
eparation, the membrane type and operating parameters such as feed flo
w rate, operating pressure, and feed should be optimized. In this stud
y the separation and recovery of sugars were targeted. It was found th
at with an increase of the feed flow rate, permeate flux increased sin
ce the effect of concentration polarization was minimized. As a result
, experiments were carried out at the highest possible flow rate. The
effect of pressure was studied at five pressures (10-50 bar). It was f
ound that there is a linear relationship between the pressure and perm
eate flux up to 30 bars. Beyond 30 bars the effect of pressure became
less significant. Thus, 30 bars was chosen as the operating pressure.
To investigate the effect of concentration, 1 to 10 weight percentage
sucrose and glucose solutions were utilized. It was observed that with
an increase in concentration, permeate flux decreased and rejections
increased, finally reaching a limiting value. Binary solutions of sucr
ose and glucose were also studied. It was seen that the separation fac
tor slightly decreased, probably due to a glucose-sucrose interaction.
Experimental data were used with a mathematical model to predict the
permeate flux and rejection. Good agreement of the predicted results w
as obtained with the experimental data for a 500 MWCO membrane.