Abstracts - peq / coppe / ufrj

Effect of Dense CO 2 on Polymeric Commercial MembranesKatia Rezzadori, Josamaique G. Veneral, Lucas Pires, J. Vladimir Oliveira, José C. C. Petrus,Marco Di Luccio*Departamento de Engenharia Química e de Alimentos, Universidade Federal de SantaCatarina – UFSC – Florianópolis/SC - 88040-900.e-mail: katia.rezzadori@gmail.com; *diluccio@enq.ufsc.brCoupling supercritical CO 2 (SC-CO 2 ) extraction with membrane separation can lead to energy savings.Also, when pressurized fluids are considered for oil extraction, membrane separation could beprofitably used for minimizing the need of solvent recompression [1]. However, high pressureconditions may cause physicochemical and morphological changes in polymeric membranes, whichcan negatively affect membrane performance [2]. Moreover, since most of the information oncommercial membranes is provided by manufacturers, further investigation on their structure wouldbe beneficial for the selection of proper membranes, especially for processes involving non-aqueoussolvents, as SC-CO 2 .In this context, the aim of the present work was to study the behavior of two commercialmembranes, one reverse osmosis (RO) membrane (BW30 – rejections of 99 % to NaCl) and onenanofiltration (NF) membrane (NP030 rejection of 80-97% to Na 2 SO 4 ) upon static exposure toSC-CO 2 . The static process was carried out with dense CO 2 in two subcritical and two supercriticalconditions (80 bar and 100 bar/20°C; 100 bar and 200 bar/ 80°C) for 8 hours. The performance wasinvestigated based on changes in physicochemical and morphological properties. These propertieswere studied using contact angle, ATR-FTIR (Fourier Transform Infrared Spectroscopy) and SEM(Scanning Electronic Microscopy).Dense CO 2 exposure caused an increase in contact angle, which was higher in elevated pressures,indicating changes in membrane hydrophilicity. The FTIR spectra indicated the presence of polyamideand polysulfone, proving the thin film composite formation of the membrane BW30. The membraneNP030 showed consecutive and sharp peaks of sulfone. After dense CO 2 permeation, a decrease inFTIR transmittance was noticed, which suggests the occurrence of swelling. After contact with denseCO 2 , membrane BW30 showed structural changes on the active layer, while the membrane NP030remained unchanged.The results obtained in this work suggest that the commercial RO and NF membranes can be appliedin the permeation of dense CO 2 , with small changes in their properties, which did not causestructural degradation, measurable with the techniques applied in these preliminary tests.[1] C.B. Sprícigo, A. Bolzan, R.A.F. Machado, L.H.C. Carlson, J.C.C. Petrus (2001), J. Membr. Sci., 188, 173-178.[2] O. Akin, F. Temelli (2011), J. Supercrit. Fluids, 60, 81-88.Acknowledgements: CAPES and CNPq