Novel ethoxylated surfactants from low-value refinery feedstocks

The synthesis, characterization, surface activity and potential application s of ethoxylated surfactants derived from low-value refinery feedstocks, a propane-precipitated asphaltene stream (PDA), catalytic cracked tars and pe troleum tars, are presented. The new tensoactive compounds were synthesized by an alkali-catalyzed ethoxylation reaction (135-150 degreesC, 20-60 psi) and were characterized by molecular weight determinations, elemental analy sis, FT-IR, and H-1 NMR. Several novel surfactants were prepared with diffe rent ethylene oxide/hydrocarbon molar ratios (from 2 up to 50) for each ref inery stream. The interfacial properties were studied using a toluene/water model system and a minimum value of interfacial tension (0.01 dyn/cm) was obtained for a 12-ethoxylated PDA tensoactive compound The results indicate d that the new surfactants have potential applications for enhanced oil rec overy (crude oil/formation water interfacial tension of approximately 0.1 d yn/cm) and as stabilizing agents for crude oil-in-water emulsions (minimum mean droplet size of 36 mum) (C) 2001 Elsevier Science Ltd. All rights rese rved.