Secondary alkane sulphonates

These surfactants are also called alkane sulphonates or secondary alkane sulphonates. They are a versatile class of surfactants with interesting chemistry and are significantly less commercialised than LAS or alkyl sulphates, due to the more complex manufacturing route and the lack of flexibility of a paraffin sulphonate manufacturing unit which can effectively produce only paraffin sulphonates. Compare this to a falling film S03 plant which can be used for the manufacture of a wide range of sulphonated and sulphated surfactants. 

Secondary alkane sulphonates, also called paraffinsulphonates, are generated by sulphochlorination or by sulphoxidation of linear paraffins. Sulphochlorination (Reed reaction) means introduction of the SO2-CI moiety in a paraffin molecule by action of CI2 and SO2 under UV-irradiation followed by hydrolysis and neutralization with NaOH. Reaction of SO2 and O2 with n-paraffins under UV light is called sulphoxidation. 

Secondary Alkane Sulphonates Readily degradable [57] Persistent [32] ... 

Preformed microemulsions containing co-solvents and co-surfactants have been used for laboratory experiments [94] and a field test [55] in Canada. The systems were developed for the extraction of a viscous oil containing up to 16% of chlorinated solvents from a site at Ville Mercier. The contaminant is a DNAPL with a density of 1.05 g/cm3 and thus exhibits only a small density difference compared to chlorinated solvents [94]. It could not be extracted effectively by the usual Winsor I systems containing n-butanol as a co-surfactant. The addition of solvents was necessary for effective solubilisation of the contaminant [94]. A preformed microemulsion containing D-limonene, toluene, n-butanol, Hostapur SAS (secondary alkane sulphonate sodium salt) and water was injected into a field test site at Thouin Sand Pit near Montreal. In previous column experiments, a composition of 13.16% D-limonene, 13.16% toluene, 9.21% n-butanol, 9.21% Hostapur SAS and 0.3% of sodium ortho-silicate in water was used as a preformed microemulsion for the extraction of DNAPL from Ville Mercier. 

Supercritical fluid extraction (SEE) turns out to be very effective in the isolation of all three surfactant classes from solid matrices. While supercritical CO2 alone did not affect significant recovery of surfactants, the addition either of modifiers or of reactants resulted in nearly quantitative recoveries. Thus, LAS and secondary alkane sulphonates (SAS) are extracted from sewage sludges in the form of tetrabufylammonium ion pairs. Lee et al. extracted NP from sewage... 

Lithium triethylborohydride continues to be a useful synthetic reagent. It has been reported that this reagent in THF reduces the toluene-p-sulphonates of primary and secondary alcohols to the corresponding alkanes. The reduction is even applicable to tosylates of cycloalkanols, hindered alcohols, and polyhydroxy derivatives. The reaction of lithium triethylborohydride with elemental sulphur has been reported to form rapidly Li aS or Li aS a (depending upon the stoicheiometry), which can then be used to prepare sulphides, RaS, and disulphides, RaS a, in high yield. Similarly, the publication of a convenient... 

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