Effect of Salinity, pH, and Temperature on Stability of Gas Condensate in Water Emulsions Using Different Surfactants

Light hydrocarbons in water emulsions are formed in many gas refinery wastewaters, and its stability depends on some parameters such as temperature, pH and salinity. In this study, different surfactants have been used to prepare gas condensates in water emulsion along with four surfactant kinds namely, Span ۸۰, Tween ۸۰, CTAB, SDS and Span ۸۰ and Tween ۸۰ mixture. For this purpose, the effects of temperature (۲۵ and ۶۰° C), pH (۳, ۵, ۷ and ۱۱) and salinity (۲, ۱۰ and ۲۶ wt. % NaCl in water) on the stability of the emulsion have been studied. In order to evaluate the stability of these emulsions, the droplet size distribution was measured by an optical microscope. The results confirm that the increasing of salinity, as well as temperature of non-ionic surfactants (Such as Span ۸۰ and Tween ۸۰), lead to more stability of the emulsion. The increasing temperature didn’t have a dominant effect on the stability of those emulsions which contain the ionic surfactants i.e., CTAB and SDS. Those emulsions formed by the combination of Span ۸۰ and Tween ۸۰ are more stable than the other ones. Results of the investigation the effect of pH on the emulsion stability clear that the emulsions are less stable at high pH than other ones.

کلیدواژه ها:

stability ، Gas condensate in water emulsion ، Droplets size distribution ، surfactant