PDMS-based membranes for dehydration of Triethylene glycol using pervaporation technology

This thesis is relying on membrane separation technology and it seeks to find an appropriate membrane to use in pervaporation setup for the subsea regeneration of triethylene glycol (TEG) in natural gas dehydration. Although some effort have been spent on membrane absorption for gas dehydration with glycols, there is still a lack of information about TEG dehydration using pervaporation technology with different membranes, therefore experimental data is needed to assess the feasibility of using membrane pervaporation for regeneration of TEG for subsea condition. In the present work, an experimental study of dehydration of TEG with pervaporation technology has been carried out using a composite membrane with the porous support of polysulfone (PSF) coated with a dense layer of Polydimethylsiloxane (PDMS). The membrane was characterized in terms of compatibility to TEG, chemical analysis identification using Fourier Transform Infrared (FTIR) spectroscopy, morphology and surface properties with scanning electron microscopy (SEM), and contact angle measurements. Furthermore, a method for analyzing low concentrations of TEG in aqueous solutions was used with gas chromatography (GC) as this was vital to the pervaporation study. The criteria for choosing PDMS polymer was the minimum TEG uptake, high flux, and lower price.