Sulph on ation with chlorosulphonic acid

Chlorosulphonic acid, particularly with batch operation, is best suited for production of a range of products on a relatively small scale. Chlorosulphonic acid is still used for the sulphonation of fatty alcohols, fatty alcohol-ethoxylates and relat detergent raw materials with OH-groups available for the attachment of a SO3H group. 

The reaction of Lauryl alcohol with chlorosulphonic acid illustrates for example the chemistry involved  

The hydrogen chloride must be absorbed to give a 30% HCl solution as a by-product. 

Sulphonation with chlorosulphonic acid requires special corrosion-proof equipment either glass-lined steel or all glass. The latter is especially suitable for small batch size sulphonation. The HCl absorber, too, is built either of glass-lined steel or is all glass. 

Bozzetto (Bergamo, Italy) offers a continuous chlorosulphonic acid sulphonation process which comprises two water-jacketed glass vessels for sulphonation and neutralisation, and a HCl absorption column. Organic feedstock and chlorosulphonic acid are mixed on a rotating disc. Under the centrifugal action of the disc, the reaction mixture is sprayed as a thin film on to the wall of the reaction vessel. The acid product falls to the base of ihe reactor and then onto a similar rotating disc system, where it is mixed with alkali and sprayed onto the wall of the neutralisation vessel. The unit is operated under slightly reduced pressure to remove HCl gas 

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