758.    DUPAS, M. R.  [Lubricant Synthesis.]  Bull. Assoc. Franc. Techniciens Petrole, No. 69, 1948, pp. 1-16; Jour. Inst. Petrol., vol. 34, 1948, p. 265 A; Chem. Abs., vol. 43, 1949, p. 1952.

     After a brief review of the chief methods for lubricating-oil synthesis, describes (with flow sheet) the process used at the Standard-Kuhlmann plant at Estaque.  Lubricating oil is produced by a Friedel-Crafts condensation of benzene with dichlorethane and a Fischer-Tropsch gas oil (180°-320°) chlorinated to a Cl content of 22-24%.  Production is effected continuously in 3 steel vessels; in the 1st vessel (at 80°) benzene, dichlorethane, and Al powder are mixed.  The chlorinated gas oil is added in the 2d stage (at 100°), and the reaction is concluded in the 3d vessel (at 120°).  Flow through the plant takes 6 hr.  The supernatant oil is separated from the AlCl3 residue, neutralized with Na2CO3 solution, and the excess benzene is removed by distillation.  Following a clay treatment to eliminate traces of AlCl3 the product is vacuum distilled yielding 2 side streams (transformer and light engine oils) and a residual bright stock.  Gas oil is removed overhead and recycled.  A further quantity of secondary oil, together with benzene and gas oil, is recovered by hydrolysis of the AlCl3 residue.  The yields (as % on the hydrocarbon charge) are:  primary oil, 45%; secondary oil, 10%; recycle, 27%; and loss, 18%.  The viscous oils (35-330 cs. at 50°) obtained have high density (0.942-0.950) and good viscosity index.

     DUPONT, G.  See abs. 1260.