GB676650A - Improvements in or relating to motor fuels - Google Patents

Abstract

A hydrocarbon motor fuel containing a minor proportion of an alkylene diamine, and which may or may not contain tetraethyl lead and an organic halide scavenging agent, is burnt in an internal combustion engine, in which hydrocarbon motor fuels containing tetraethyl lead and an organic halide scavenging agent have been burnt, prior to a period of idleness of said engine. The internal surfaces of the engine are thereby protected against rust. The preferred diamines are of formula H2N-R-NH2 when R is a straight or branched chain alkylene group of 2-5 carbon atoms. The amine groups may be attached to any carbon atom, but it is preferred that they should be attached to carbon atoms which are adjacent or separated by not more than one carbon atom. The amount added may be between 0.03 and 5 per cent by volume, and preferably 0.1 to 1.0 per cent. Although it is preferred to run the engine for a short time before storage using a fuel containing an alkylene diamine with or without tetraethyl lead and a scavenging agent, if desired it may be run normally on a fuel containing the alkylene diamine, as well as tetraethyl lead and a scavenging agent. In this case, relatively smaller amounts may be employed (minimum 0.01 per cent). In an example a fuel comprising an aviation fuel (octane No. 80), tetraethyl lead, ethylene dibromide and 0.1 per cent by volume of propylene diamine is compared with respect to its rust inhibiting properties with the same aviation fuel containing only tetraethyl lead and ethylene dibromide.