Membranas de fibra oca de carbeto de silício para separação de água-óleo.

Abstract

Silicon carbide (SiC) is a promising material for membrane production due to itsthermal shock resistance, excellent chemical and mechanical stability. Therefore, theaim of this work is to develop and characterize SiC membranes, with greaterselectivity and greater flow, in the form of hollow fiber, aiming to apply in the water-oil emulsion separation. A solution was prepared and by the extrusion technique withimmersion precipitation and after sintering at 1500 °C, membranes were obtainedwith hollow fiber geometry. For the characterization of the SiC, spectroscopyanalyzes were performed in the infrared region with Fourrier transform (FTIR), X-ray diffraction (XRD), particle size distribution and scanning electron microscopy (SEM);and for thecharacterization of the membranes it were performed: thermogravimetryanalyses (TG), FTIR, XRD, contact angle, porosity and SEM were used to evaluatethe morphology and composition of membranes obtained before and after sintering.The membranes were submitted to the water flow measurements and water-oilemulsion separation efficiency. XRD and SEM analyses of SiC powder showed,respectively, characteristic peaks of the silicon carbide, alumina and quartz phases;and plates with irregular shapes and sharp edges. The SiC granulometric distributionrange extends from 0.04 μm to 5 μm, with average particle diameter of 1.38 μm.There were changes in the profile of the infrared spectra of the fiber after burning dueto the high sintering temperature, which caused that the organic materials present inthe solution were eliminated for the formation of the membrane structure. SEMimages of the membrane cross section showed that these are porous asymmetrical with a selective layer on the inside and a porous layer on the outside of themembrane. The membrane with a 5 cm “gap” had a higher permeability value of 476.33 L/h.m2.bar. It is possible to conclude that the membranes presented a highseparation coeficient, above 84%. Therefore, they met the requirements ofResolution 430 of CONAMA, proving the potential for water-oil separation.