GB719776A - Diesel fuel - Google Patents

Abstract

Lead sulphonates and naphthenates are employed as ingredients in fuel oil compositions (see Group III). Specification 674,765, [Group III], is referred to. Lead mahogany sulphonate.-Crude calcium mahogany sulphonate (50 per cent oil) is dissolved in a petroleum distillate (boiling range 185-290 DEG F.) and the solution is repeatedly washed with aqueous lead nitrate in the presence of ethyl alcohol with steam agitation. A small amount of litharge is added to neutralize any acidity and the petroleum distillate is distilled off, leaving a concentrate of lead mahogany sulphonate. Lead alkyl benzene sulphonate.-Benzene is alkylated with polypropylene (a C12-C15 olefin cut) and the alkylated benzene is sulphonated with concentrated sulphuric acid and then neutralized with sodium hydroxide. The sodium sulphonate is reacted with lead nitrate to obtain the lead sulphonate. Basic lead alkyl benzene sulphonate.-The alkyl benzene sulphonic acid prepared as above is reacted with a 100 per cent stoichiometric excess of litharge to obtain the basic lead salt. Lead naphthenate.-Petroleum gas oil is washed with aqueous caustic soda and the aqueous sodium naphthenate solution is treated with strong sulphuric acid to release the naphthenic acid. This is distilled and then treated with litharge. Lead naphthenate is extracted from the reaction mixture with Stoddard solvent.ALSO:A composition which, in spite of its sulphur content, causes little engine wear when employed as a fuel for diesel engines comprises a petroleum distillate boiling in the range of about 350-750 DEG F. and having an A.P.I. gravity above 20 DEG and a sulphur content above about 0.5 per cent. by weight, together with a minor proportion of an oil-soluble lead naphthenate, lead sulphonate and/or lead salt of a fatty acid, sufficient to give the composition a lead content of about 0.005-0.07 per cent. by weight. The sulphonic acids from which suitable lead sulphonates are prepared are preferably those having a molecular weight above about 400, for example sulphonic acids obtained by sulphonating white oils, petroleum lubricating oil fractions, higher boiling fractions of SO2 extracts of petroleum gas oils, and high boiling synthetic alkylated aromatic hydrocarbons, such as those formed by alkylating benzene with propylene polymers, butylene polymers or mixed propylene-butylene polymers. Lead salts of fatty acids mentioned are the oleate, palmitate, and stearate, and the soaps prepared from unrefined fats. In the examples, the normal or basic lead salt of naphthenic acids of molecular weight above about 225, or of sulphonic acids prepared by alkylating benzene with polypropylene (C12-C15 cut) and sulphonating the product, is added to the petroleum distillate. Specification 674,765 is referred to.