Abstract: The present invention provides a method for preparing a hydrocarbon mixture solvent comprising 1 to 15 wt % of alkyl tetralins and 0 to 10 wt % of aromatic hydrocarbons and having a boiling point of 160.degree. to 300.degree. C., the solvent being substantially free from naphthalene and biphenyl; the method being characterized by comprising the steps of subjecting a kerosene fraction having a boiling point of 150.degree. to 300.degree. C. to a nucleus hydrogenation treatment at a temperature of 100.degree. to 300.degree. C. at a pressure of 30 to 100 kg/cm.sup.2 in the presence of a metallic catalyst for nucleus hydrogenation of aromatic nuclei; separating and removing at least a part of n-paraffins in the kerosene therefrom by the use of a molecular sieve made from a synthesized zeolite having pores of 5 .ANG. in diameter in order to obtain a residual oil; and subjecting the latter to a rectification.

Abstract: A fuel composition comprising a hydrogenated material obtained by hydrogenating a reaction mixture ranging from C.sub.11 to C.sub.16 containing mainly compounds which comprise butadiene and cyclopentadiene as basic structural units, produced by reacting an acyclic conjugated diene with cyclopentadiene, dicyclopentadiene, an alkyl-substituted cyclopentadiene, or an alkyl-substituted dicyclopentadiene in accordance with Diels-Alder reaction an isomeric material prepared by isomerizing the hydrogenated material or the mixture of the hydrogenated material and the isomeric material.