GB479345A - Improvements relating to the production of motor fuel - Google Patents

Abstract

An aviation or motor spirit or constituent thereof is obtained by the alkylation of an isoparaffin. Iso-butane or iso-pentane is condensed with an olefine or olefines, e.g. propylene, iso- or n-butene or the lower polymerides thereof, particularly the dimeride and trimeride, in the presence of sulphuric acid at low temperatures, e.g. -10 to + 30 DEG C. and in substantially equimolecular proportions. On settlement, an upper hydrocarbon layer separates, from which the spirit may be produced by distillation. Normal paraffins or inert hydrocarbons may be present, but preferably aromatic hydrocarbons are absent. An excess of the iso-paraffin may be used, and this is stated to increase the yield of the condensate. The reaction is carried out in the liquid phase and if necessary, pressure sufficient to maintain the liquid phase may be used. The iso-paraffin may be mixed with the acid, and the olefine added gradually with vigorous stirring, which may be maintained after all the reactants are mixed. Examples describe products obtained from iso-butane and diisobutene; iso-pentane and diisobutene; isobutane and a polymer gasoline produced by the catalytic polymerization of olefines; isobutane and iso-butene, alone or mixed with diisobutene or triisobutene; iso-butane and propylene; iso-butane and butene-2; isobutane and the product formed by condensation of butene and iso-butene from a C4 cut, and called butene-isobutene polymer; iso-butane and a crude C4 cut, at temperatures ranging from -10 to + 30 DEG C. The yield, bromine numbers, anti-knock ratings, &c. of the products are given. The anti-knock ratings may be increased by the addition of tetra-ethyl lead. According to the first and second Provisional Specifications, the iso-paraffin may be replaced by a naphthene containing a tertiary carbon atom.ALSO:An aviation or motor spirit or constituent thereof is obtained by the alkylation of an iso-paraffin. Iso-butane or iso-pentane is condensed with an olefine, e.g. propylene, iso- or n-butane or the lower polymerides thereof, in the presence of sulphuric acid at low temperatures, e.g. -10 to +30 DEG C., and in substantially equimolecular proportions. Normal paraffins or inert hydrocarbons may be present, but preferably aromatic hydrocarbons are absent. The anti-knock ratings of the products may be increased by the addition of tetra-ethyl lead.