Abstract: The invention concerns a jet engine fuel having the following characteristics:i) distilling range from 140 to 300.degree. C.;ii) cis-decalin/trans-decalin ratio greater than 0.2;iii) aromatics content less than 22% by volume;iv) sulfur content less than 100 ppm, andv) lower heating value per unit volume greater than 34.65 Mj/liter.Also process for making the same wherein for example a cut from catalytic cracking distilling between 140 and 300.degree.0 C. is subjected to a hydrotreatment step and then to a dearomatization step.

Abstract: The present invention relates to a process for dechlorinating a spent lubricating oil fraction, optionally mixed with another hydrocarbon stock. Upstream of the recycling operation in refining the spent oil, the latter is subjected to a dechlorination operation at least partially by passing it on a bed of particles (6) of a composition which neutralizes by absorption and containing, as active compound capable of fixing the chlorine, at least one metal oxide and/or at least one metal hydroxide.

Abstract: A method of isomerizing n-paraffins into isoparaffins in a cut of hydrocarbons with four carbon atoms or of hydrocarbons with five and/or six carbon atoms. The cut being processed enters at least one reactor containing a stationary catalyst bed. The charge travels over the bed. Either the rate of isomerization in the effluents or a parameter directly dependent thereon (such as the octane number) is preferably continuously measured. Some of the upstream catalyst, specifically between 1/3 and 2/3, is replaced with fresh catalyst once that rate has decreased 10 to 30% below a prescribed point. The charge is redirected through the reactor once the catalyst has been replaced.

Abstract: A process for deasphalting a heavy hydrocarbon feedstock, comprising two stages of precipitation from the feedstock of an asphaltene fraction alone or, alternatively, of a resin fraction along with the asphaltene fraction, by means of a heavy solvent and a light solvent, respectively, is disclosed.In accordance with the process, the heavy solvent and the light solvent both contain, in different proportions, at least one hydrocarbon having 3 carbon atoms and at least one hydrocarbon having at least 5 carbon atoms, the proportion of the hydrocarbon having 3 carbon atoms being higher in the light solvent than in the heavy solvent.

Abstract: Process for deasphalting a hydrocarbon charge by means of a deasphalting solvent.The charge (1) is introduced, at 100.degree.-200.degree. C., in admixture with a deasphalting solvent (3and 4), into a settler (7). The deasphalted oil (24) is separated from the solvent (23). Asphalt (9) is washed in a column and then separated from the washing liquid (21).