Patent GB-741807-A (GB)
Title: Improvements in or relating to a method of neutralizing acidic stock and the resulting product
Filed: 1951-05-25
Abstract: The invention comprises a method of neutralizing an acidic stock consisting of sulphonated and sulphated organic compounds having an aliphatic radical containing 8 to 18 carbon atoms and the alkali metal salts of which have detergent properties, that includes converting the stock to a slurry of a water-dispersible alkali metal salt thereof by introducing a stream of the stock and a separate stream of an alkali metal hydroxide into each of a plurality of small mixing chambers within which the combined streams have short residence time, and discharging the resulting mixture from the chamber in divided and extended surface form openly within and through the atmosphere of a low-pressure zone maintained at a pressure of 9 to 88 mm. of mercury and a temperature of 50 DEG  to 120 DEG  F., and flowing the slurry from the zone.  Illustrative of specified sulphonates or sulphates are n-dodecyl-, undecane-2- and pentadecane-4-hydrogen sulphate, dodecane-1-benzene- and undecane-1-benzyl-hydrogen sulphate, undecane-2- and hexadecane-8-sulphonic acid and n-dodecyl-toluene- and undecane-1-benzyl sulphonic acid.  Mixtures of sulphates and sulphonates may be treated.  Intimate admixture of reactants is effected in apparatus fitted with spray nozzles some slurry preferably being recirculated to the mixing stage to act as an alkali carrier and a dispersing medium for the neutralization.  Preferably at the commencement of the reaction, a quantity of alkali equivalent to the stoichiometricl quantity of acidic stock to be neutralized is present in the mixing chambers. Preferably the final slurry should have a viscosity of 500-1500 centiposes at 100 DEG  F. and may then be spray dried optionally with the addition of builders or fillers, c.f. Group III.  The spray drying is preferably performed at low pressures to effect removal of air and volatiles as in Specification 741,806, [Group III]. Diagrams of suitable apparatus are provided in which the feed stock is made by treating a mixture of benzenoid hydrocarbons having an alkyl substituent containing 8 to 18 carbon atoms with 25 per cent oleum.ALSO:An acidic stock consisting of sulphonated or sulphated organic compounds having an aliphatic radicle of 8-18 carbon atoms, the alkali metal salts of which are detergents, is neutralized by conversion to a slurry of a water-dispersible alkali metal salt thereof by introducing a stream of the stock and a separate stream of an alkali metal hydroxide into each of a plurality of small mixing chambers, and discharging the mixture from the chambers in divided and extended surface form through a low pressure zone maintained at 9-88 m.m.s Hg. and 50-120 DEG F (see Group IV (b)).  To the slurry thus obtained there are added fillers and builders before recovery of the product by spray drying. Specified builders are soda ash, sodium bicarbonate, sodium citrate, carboxy methyl cellulose, alkali metal silicates and phosphates and borax.  Specied fillers are sodium sulphate and chloride, silica and Fullers' earth.  Illustrative of specified sulphonates and sulphates are n-dodecyl-, undecane-2- and pentadecane-4-hydrogen sulphates, dodecane-1-benzene- and undecane-1-benzylhydrogen sulphates, undecane-2- and hexadecane-8-sulphonic acids and n-dodecyltoluene- and undecane -7-benzyl sulphonic acids.  Mixtures of sulphates and sulphonates may be used.  The spray drying is preferably performed at low pressures to effect removal of air and volatiles, as in Specification 741,806. Diagrams of suitable apparatus are provided.  A typical feed stock is made by treating a mixture of benzenoid hydrocarbons having an alkyl substituent of 8-18 carbon atoms with 25 per cent oleum.