GB792643A - Process for preparing aviation fuels - Google Patents

Abstract

A mixture of liquid hydrocarbons suitable for use as an aviation fuel component is prepared by separating from a naphthenic straightrun gasoline, a fraction having an initial boiling point of 65 DEG C. and a final boiling point between 130 to 140 DEG C., catalytically reforming this fraction and mixing the reformate with all or part of the fraction of the gasoline boiling below 65 DEG C. The gasoline may be such that the fraction boiling between 65 DEG C. and 85 DEG to 95 DEG C. contains 15 per cent by weight of normal hexane. The catalytic reforming treatment may be carried out using as catalyst platinum supported on alumina, silica-alumina or silica-magnesia, molybdenum oxide supported on alumina, or chromium oxide supported on alumina, at a pressure below 50 atmospheres and at a temperature between 450 DEG and 525 DEG C. When the reformate has been mixed with the fraction boiling below 65 DEG C. pentane and lighter hydrocarbons present in the mixture may be removed. A fraction boiling above 105 DEG C. may be separated from the mixture and a portion of it returned to the resulting mixture in an amount not exceeding 10 to 20 per cent by volume of the reformate-containing product. The liquid hydrocarbon mixture may be blended with an alkylate prepared from isobutane and a mixture of butenes and pentenes, and with isopentane and butane, so that the resulting product contains at least 30 per cent by volume of the mixture of reformate and fraction boiling below 65 DEG C., and less than 50 per cent by volume of the alkylate. Tetra-ethyl lead may be added to the compositions. Examples of the process are given.