Multiple membranes for removing voc's from liquids

EXAMPLE

[0044]The following example is for illustrative purpose only and is not intended to limit the scope of the invention.

Example 1

Extraction Optimization Using a 2-Stage Membrane

[0045]The following example demonstrates extraction optimization using a 2-stage membrane setup as shown in FIG. 1. The outlet latex VOC concentration for a 2-membrane system can be estimated when the inlet VOC concentration is known. If a latex inlet VOC concentration is 500 ppm and a feed rate of latex is 0.02 mL / s, the outlet VOC concentration is estimated to be 175 ppm using two membrane modules and no recycle of latex. The governing equation used for this calculation is as follows:

m(Cin-Cout)=kA(Cin-Cout)ln(CinCout)[0046]=flow rate of latex, mL / s[0047]in>=concentration of VOC in feed latex, ppm[0048]out>=concentration of VOC in exit latex, ppm[0049]=mass transfer coefficient, cm / s[0050]=membrane area, cm2

[0051]To lower the outlet VOC concentration, the recycle flow rate was increased but the net flow rate through each module was kept the same. For this example, enough latex was recycled to achieve a total flow rate to