Studies On The Interfacial Adsorption Properties With The Molecular Weight And Its Distribution Of Alkyl Aryl Sulfonates

Eighth kinds of alkylaryl sulfonate which had clear structure and high purity were synthesized from benzene and its analogies, acyl chloride and alkyl halide. The content of all the products were all over 95% determined by two-phase titration.Liquid-solid ratio of solid/liquid interface adsorption was 60, and saturation adsorption time was 32 hours. The isotherms and the adsorption amount of five types of molecular weight distribution formed from the mixture of five molecular weight alkyl aryl sulfonates on solid-liquid interface were measured. The impacts of the molecular weight, molecular weight distribution, adsorption temperature, the inorganic salt , alkalis and alcohols on the adsorption of alkyl aryl sulfonates compound on the oil sand / quartz sand surface were discussed, respectively. The results showed that the adsorption amount of five types of molecular weight distribution formed from alkyl aryl sulfonate compounds were in turn decreased reduce in the following order, i.e., the incremental distribution, normal distribution, reverse normal distribution, decreasing distribution, uniform distribution; while the adsorption amount of alkyl aryl sulfonate compound on the oil sands surface increased with their molecular weights, decreased with the adsorption temperature, increased with the NaCl concentration, increases with the increasing NaOH and NaCO₃ concentration , decreases with increasing NaHCO₃ and KHCO₃ concentration, and gradually decreases with the increasing alcohols concentration and alcohols carbon chain.. The effect of NaCl on the adsorption of the alkyl aryl sulfonate compound on the oil sands surface was slightly larger than on the quartz sand surface.Moreover, it was found that the effect of addition of CaCl₂, MgCl₂, Na₂SO₄ etc. on the adsorption amount was more significant than NaCl. The effect of the isobutanol on the adsorption of complex systems was in turn bigger than tertiary butanol and n-butyl alcohol.The interface tension of alkyl aryl sulfonates compound with series of n-alkanes, the simulation oil phase of crude oil and its various components in 1th plant of Daqing oilfield was measured by spin-drop method at 45℃.The nmin of alkyl aryl sulfonates compound system which average molecular weight were 390, 432 and 446, were 9 ,11 and 11, and the nmin corresponding to the minimum interfacial tension value from small to large complex systems were showed as: reverse normal distribution< incremental distribution< uniform distribution< normal distribution< descending distribution. The nmin of 404 molecular weight complex systems were 10 except incremental distribution and descending distribution were 11, and then the nmin corresponding to the minimum interfacial tension value from small to large complex systems were showed as: reverse normal distribution< incremental distribution< uniform distribution< normal distribution< descending distribution. The nmin of 418 molecular weight complex systems were 10 , and the nmin corresponding to the minimum interfacial tension value from small to large complex systems were showed as: reverse normal distribution< incremental distribution< uniform distribution< descending distribution < normal distribution. The minimum dynamic interfacial tension was decreased with the increasing NaOH concentration, and it was lowest When best caustic concentration (0.2mol/L), then it was increased, finally, it tended to be balanced. The interfacial tension was decreased with the increasing alkyl benzene sulfonate compound concentration, When the surfactant concentration reached a value, the interfacial tension was increased with the increasing concentration. The 432 molecular weight complex systems were the best to increase the Oil-water interfacial tension ,and they matched best with the crude oil of 1th plant of Daqing oilfield. The crude oil of 1th plant and its various components matched best with the 404⁴32 molecular weight complex systems, and the Oil-water interfacial tension can reach ultra-low interfacial tension values. Reverse normal distribution complex systems the ability to reduce the interfacial tension was relatively strong, and the interface between the components of crude oil matched best. Descending distribution complex systems the ability to reduce the interfacial tension was relatively poor.