Rapid and Efficient Demulsification of W/O Emulsions of Crude Oil by Nanocomposites based on Titanium Dioxide with Carbonaceous Substrates

TiO2 nanocomposites on carbonaceous compounds, such as carboxyl-functionalized, multi-walled carbon nanotubes (MWCNT-COOH), and graphene oxide (GO) were synthesized by the sol-gel method. The samples were coded as TiO2 (T), TiO2-MWCNT-COOH (TM), and TiO2-GO (TG). The effect of the addition of carbonaceous compounds on the enhancement of demulsification efficiency of TiO2 nanocomposites ‎in crude oil (W/O) emulsions was then investigated. FT-IR, Raman, and morphological analyses such as FE-SEM, EDXS, XRD, HR-TEM, DRS, BET surface area, and TGA were used to determine the properties and structures of the nanoparticles prepared. In addition, the demulsification efficiency of three nanoparticles was studied under various concentrations, settling times, and temperature conditions by bottle test. According to the screening results, TG was selected as the best sample. The response surface method with a central composite design (CCD) was used to optimize the demulsification activity of TiO2 nanocomposites with graphene oxide (TG). Thus, the impacts of temperature, demulsifier concentration, and time were studied by the RSM-CCD method. Ultimately, the results indicated ~100% demulsification efficiency under optimal conditions at concentration, temperature, and time of 75 ppm, 65˚C, and 120 min., respectively.