GB911491A - Scavenger-free gasoline - Google Patents

Abstract

A gasoline composition contains from 1,5-4,3 grams of lead per U.S. gallon as an alkyl lead anti-knock agent, a gasoline soluble organic phosphorus compound present in amount such that the phosphorus to lead atom ratio is from 0,4:3 to 4:3 and an acidic compound, esters or aldehydes present in an amount ranging from 0,05 to 5% by volume based on the fuel, the base fuel containing from 10 to 60% by volume of aromatic hydrocarbons with the balance being non-aromatic hydrocarbons and having a nominal octane number of at least 90, the motor octane number being not more than 12 octane numbers less than its research octane number. The alkyl lead compound may be tetramethyl lead ethyltrimethyl lead, diethyldimethyl lead, methyltriethyl lead, tetrapropyl lead, tetraisopropyl lead, ethyltributyl lead or tetraamyl lead, the preferred compound being tetraethyl lead. The phosphorus compound may be triethyl phosphate, tributyl phosphate, tributylphosphite, tri-(2-ethylhexyl) phosphate, tris-(2-butoxyethyl) phosphate, tri-(2-chloroethyl) phosphate, tri-(b -chloropropyl) thionophosphate, triisopropylthionophosphate, tricyclohexylphosphite, triphenylphosphite, triphenylphosphate, tricrestylphosphate, cresyldiphenylphosphate, phenyldicresylphosphate, dioctylphenylphosphate, trimethylphosphate, phenyldimethylphosphate, cresyldimethylphosphate, xylyldimethylphosphate, diethylbutylphosphonate, bis-(2-chloroethyl) vinylphosphonate, S,S-di-butyl phenylphosphonodithioate, ditolychloromethyl-phosphonate, tris-(dimethylamido) phosphate, dixylylphorphoramidate, tributyl phosphine oxide or the corresponding phosphinates, phosphonites, thiophosphinates, phosphine oxides or phosphine sulphides. The reaction products of phosphorus sulphide with various organic substances may also be used. Suitable acidic compounds are monocarboxylic acids containing from 1 to 30 carbon atoms per molecule and containing no more than 3 oxygen atoms per molecule. A tertiary aliphatic hydrocarbon carbon ester or an anhyride of such an acid or an aldehyde may be used instead. Examples of suitable compounds are isobutyraldehyde, 2-ethylhexanoic acid, benzoic acid, tertiary butyl acetate, tertiary butyl-2-ethylhexanoate, tertiary-butylbenzoate, cyclohexane carboxylic acid, hexanoic acid, tertiarybutyl propionate, tertiary-amyl acetate, isobutyric anhydride, n-butyric anhydride, propionic anhydride, acetic anhydride, n-butyaldehyde, benzaldehyde, cumic acid, (neopentyl tertiarybutyl)- methylacetic acid, capric acid, lauric acid, ethoxyacetic acid, methoxy-acetic acid, 4-ketostearic acid, levulinic acid, 2-ethyl-hexaldehyde, paraldehyde, propionaldehyde, cinnamic acid, phenylacetic acid, di-(neopentyl)-acetic acid, 4-methylvaleric acid, 2-ethylbutyric acid, behenic acid, oleic acid, stearic acid, palmitic acid, myristic acid, pelargonic acid, heptanoic acid, caproic acid, propionic acid, acetic acid, and formic acid. The composition may also contain an aromatic amine such as methylaniline or a methyl toluidine or methyl xylidine or mixtures thereof; many other examples of suitable amines are given. Organometallic compounds of manganese, nickel, iron or cobalt may also be included. Other optional additives include anti-oxidants, e.g. N,N1-di-sec-butyl-p-phenylediamine, p-N-butyl-aminophenol, 4-methyl-2, 6-di-tert-butyl phenol, 2,6-di-tert-butyl phenol), metal deactivators (e.g. N,N1-disalicylidene-1,2-diaminopropane. The base fuel must contain from 10-60% of aromatics, the balance being saturates, olefines, naphthenes or combinations of these. The aromatic components may be catalytic reformates; the olefins may be formed by thermal cracking, catalytic cracking or polymerization; the saturated components comprise paraffins and naphthenes and may be straight-run gasolines, alkylates or isomerizates. The base fuel must have a nominal octane number of at least 90. Nominal octane number is defined as the octane number of the gasoline when it contains 3cc. of tetraethyl lead per U.S. gallon.