Study of the effect of Eucalyptus globulus lignin and Schinus terebinthifolius tannin extract on water in oil emulsions of heavy oil

Abstract

Water-in-oil emulsions (W/O) are very stable in heavy oils due to the high amount of polar compounds. Natural products are rich sources of substances with polar characteristics, so the present work studied the effect of the addition of lignin and aroeira extract in W/O emulsions in heavy oil (13.7 °API) with 7 wt% of asphaltenes and 32 wt% of resins, respectively. W/O emulsions were prepared using: formation water; formation water with lignin in natura; formation water with modified lignin and formation water with aroeira extract (at concentrations 0.5 and 3.0% w/v). The emulsions were homogenized at 5000 rpm for 3 min. The homogeneity and stability of the emulsions were verified by photomicrography and droplet size distribution (DSD) using an optical microscope. Emulsions spectra were obtained in the mid-region infrared and these data were analysed by principal component analysis (PCA). The results showed that lignin in natura and modified lignin acted as emulsifying agents when added in low concentration (0.5% w/v). PCA showed that the emulsion prepared with 30% w/v aqueous phase containing tannin (aroeira extract) had a different response as compared with the other W/O emulsions. This suggests that W/O emulsions prepared with formation water and lignin (in natura and modified) did not alter the oil chemical profile.