SYNTHESIS OF SODIUM PETROLEUM SULFONATES AND THEIR INTERFACIAL ACTIVITY AGAINST INDIAN CRUDE-OIL

Aromatic rich hydrocarbon phase is separated from lube base stock by u sing solvent extraction method. Acetonitrile is used as solvent. Sodiu m petroleum sulphonates are prepared by sulphonation with concentrated (98%) sulphuric acid followed by neutralization with alkali solution. The formation of high molecular weight oil soluble petroleum sulphona tes, i.e., benzene soluble and chloroform soluble sulphonates constitu te only 45% of the total sulphonates produced. Low concentration surfa ctant slugs are prepared using isoamyl alcohol as cosurfactant and sod ium chloride as brine, while oil soluble sulphonates are surfactants. Both chloroform and benzene soluble sulphonates could produce low inte rfacial tension (IFT) in the order of 10(-2) mN/m against Naharkatiya (NHK) crude oil. Chloroform soluble sulphonate produce ultra low IFT a gainst heptane, while higher molecular weight benzene soluble sulphona te gives lowest IFT against nonane. The interfacial activity of chloro form soluble sulphonates indicate that heptane is the equivalent alkan e carbon number (EACN) of NKK crude oil.