Date of Award

Fall 1996

Document Type

Thesis

Degree Name

Master of Science in Chemical Engineering - (M.S.)

Department

Chemical Engineering, Chemistry and Environmental Science

First Advisor

Kamalesh K. Sirkar

Second Advisor

Angelo J. Perna

Third Advisor

Robert G. Luo

Abstract

Removal and recovery of evaporated lighter gasoline fractions can be effectively implemented by selectively permeating the hydrocarbons (HCs) and other volatile organic compounds (VOCs) from the vented air streams through nonporous hydrophobic polymeric membranes subjected to vacuum on the permeate side and then condensing these organics from the permeate. Such a vapor permeation process employing spiral-wound membranes has already been commercialized for VOCs. In this study, attention has been focused on removal of hydrocarbons from nitrogen flowing through the bore of microporous hydrophobic hollow fibers with a specially engineered nonporous silicone coating on the outside surface with a view to reducing the HC concentration in treated gas stream from 17% to the lowest desirable level. Membrane modules containing such hollow fibers possess 7-10 times more surface area per unit volume, have higher selectivities to hydrocarbons and lowered air flux due to the flow configuration, pore condensation and the membrane type. Studies with an inert liquid immobilized in the substrate pores of the membranes (ILM) have shown very high selectivities compared to the composite membrane. A mathematical model has been developed to explain the permeation-separation behavior of the hydrocarbons and the VOCs as well. A novel aspect of the model is the effort made to illustrate and explain the difference between the two modes of introduction of the feed viz. shell-side and tube-side.

Share

COinS