development in the preparation of sulfonic acid and sulfonate

摘要

1358095 Separation of sulphonic acids SOC NATIONALE DES PETROLES D'AQUITAINE 6 Aug 1971 [7 Aug 1970 22 July 1971] 37075/71 Heading C2C A process for the separation of hydrocarbon sulphonic acids from a sulphonic acids solution A containing also sulphuric acid, water and possibly non-sulphonated hydrocarbons comprises adding to the solution at least one slightly polar alcohol having at least 5 carbon atoms and which is substantially unreactive towards sulphuric acid to cause separation of the solution into an organic phase B containing the sulphonic acids and an aqueous phase containing almost all of the sulphuric acid, separating the organic phase from the aqueous phase and treating the former to separate out the sulphonic acids as free acids or salts. The sulphonic acids may be separated from any unreacted hydrocarbons by treating A or B with a light polar solvent which is immiscible with the hydrocarbons and which causes separation of the hydrocarbons. When added to A the light polar solvent may be recovered therefrom by distillation after separation of the hydrocarbons. The organic phase after separation of the hydrocarbons, may be (a) treated with an alkaline or alkaline earth metal hydroxide to neutralize the sulphonic acids therein to sulphonates from which the slightly polar alcohol are separated by evaporation at a temperature and pressure at which the sulphonates are molten or (b) have water added to it to form an azeotropic mixture with the alcohol which is removed from the sulphonic acids by distillation at subatmospheric pressure. The molten sulphonate from (a) may be atomized in a current of cold inert gas to form a powder which is free flowing and anhydrous and may have a grain size between 40 to 600 Á.