Studies On Alkyl Alkylaryl Sulphonates Molecular Weight And Its Distribution On The Solid-liquid And Liquid-liquid Interface Adsorption

In this paper, twelve kinds of alkyl aryl sulfonates which had definite structure and highpurity were finely synthesized from methylbenzene and its homologues, acyl chloride,-bromoalkane, and alkali, the synthesized process concluded Friedel-Crafts reaction,Grignard reaction, catalyzed hydrogenation, sulfonation and neutralization. The content ofsurfactant in the products were all more than95.0%determined by two-phase titration. Ninesingle structure of alkyl aryl sulfonate were made into five kinds of molecular weight, whichwere390、404、418、432and446, respectively. Five different molecular weight distributionswere increment distribution, descending distribution, uniform distribution, reverse uniformdistribution, normal distribution.Liquid-solid ratio of solid/liquid interface adsorption was50：1, and saturationadsorption time of oil sands and quartz sands was28and12hours, respectively. Theinfluence of adsorptive time, adsorptive temperature, the concentration of sulfonate, salts,alkalis, alcohols on the efficiency of absorption were investigated on oil sands and quartzsands. The dynamical results show that:（1） the absorption capacity changes with time wasdescribed well by Elovich equation. The adsorption activation energy rate constants of alkylsulfonates were similar, but increasing the molecular weight of the sulfonates the absorptioncapacity was increased; the related coefficient, r²was between0.9816and0.9929whichshowed that the adsorption process wasn’t a simple level1reaction, but process was decidedby the reaction rate and diffusion factor;（2） the absorption capacity increased withdecreased the addition of temperature. The adsorption of alkyaryl sulfonates could be welldescribed by the Langmuir type, the adsorption process was exothermic by the negativeadsorption enthalpy;（3） the absorption capacity increased with the addition concentrationand molecular weight of alkyaryl sulfonates. In changed concentration of additives, theabsorption capacity increased with the addition of salt and the influence of Na₂SO₄was biggerthan NaCl; the absorption capacity increased with the addition of alkali and the influence ofNaOH was bigger than Na₂CO₃; the absorption capacity decreased with the addition of withalcohol. The influence by kinds of alcohol was different and the results by large to small wastertiary butanol, isobutyl alcohol and n-butyl alcohol, respectively. In the same condition, theabsorption capacity of alkyl aryl sulfonates in the oil sands was bigger than quartz sands.Using the interfacial tension scanning method, we could research the relation of theinterface between the third plant of Daqing crude oil and its components by putting9series of alkyl aryl sulfonates into5different molecular weights. The study showed that the interfacialtension was changed with the same average molecular weight and different molecular weightdistribution and it was also different by the same molecular weight distribution and differentaverage molecular weight.