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.