Date of Award
Master of Science in Chemical Engineering - (M.S.)
Chemical Engineering, Chemistry and Environmental Science
Kamalesh K. Sirkar
Robert G. Luo
An aqueous solution of a volatile organic compound (VOC) e.g. trichloroethylene (TCE) is passed through the bores of hydrophobic microporous polypropylene hollow fibers having a plasma polymerized silicone coating on the fiber outside diameter; a vacuum is maintained on the shell side of the fiber to remove the VOC and recover it by condensation. Process performance has been obtained over a range of feed flow rates, concentrations of VOC and the surfactant (sodium dodecyl sulfate (SDS)). In solutions without surfactant or low surfactant concentrations, the pores are not wetted and remain gas-filled. The VOC is stripped from the solution into the gas-filled pores, diffuse through the gas-filled pore and then permeate through the silicone coating to the shell side where vacuum removes it. This process is termed "stripmeation". The observed VOC permeation and removal behavior in stripmeation has been modeled using resistances-in-series approach; the model-estimated values compare well with the experimental values for surfactant-free feed solutions. For surfactant-containing feed solutions, with an increase in surfactant concentration the VOC flux decreases. Experiments conducted to identify and estimate the resistances show that as the surfactant solution wets the pores, the water-filled pores offer additional resistance. Other resistances may be due to unavailability of VOC in the aqueous phase and an adsorbed surfactant layer on the polypropylene substrate. Comparison between tube-side feed and shell-side feed was made for aqueous and surfactant feed. The tube-side feed-based operation performs much better.
Das, Anirban, "Removal of VOCs from superfactant-flushed wastewater by membrane based modified pervaporation process" (1997). Theses. 923.