2631.     ---------------.  [PETROLEUM (LONDON).]  Synthetic Fuels in Germany.  III (2).  Fischer-Tropsch Process, Lubricating Oils and Acetylene.  Vol. 9, 1946, p. 191.

        2 processes are described briefly:  That of the Kuhlmann Co. at Lestaque, France (capacity 25 tons per day) and a pilot plant at Harnes, France.  To produce 1 ton of lubricant, the 1^st process requires 600 kg Fischer-Tropsch gas oil, 600 of benzol, and 160 of dichlorethane.  The gas oil is chlorinated at 90°-100° and is mixed with a benzol-dichlorethane mixture in the presence of AlCl₃ at 70° and then raised to 110°.  the mixing time is 6 hr.; 10% of AlCl₂ is used.  The liquid product is stripped of the uncombined benzol, allowed to settle, the AlCl₃ sludge is removed by water washing, and the washed oil is blended with gas oil to lower its viscosity and is used as a general machine-lubricating oil where a high-grade oil is unnecessary.  The upper layer, after decantation, is clay-treated and distilled, the overhead product (20%) is sent back for reprocessing, the upper side stream product (30%) being used as a transformer oil.  The bottoms make a high-grade steam-cylinder oil (20%), which can be used at superheat temperatures up to 350°; 30% of turbine oil also is obtained.  The oils formed consist of polybenzenes with long paraffinic chains attached; this structure gives the oils a high viscosity index and a low pour point.  The properties of some of the oils are shown in a table.  In the 2d process the raw material is Fischer-Tropsch gasoline of as high olefin content as possible.  This is mixed with 3% of AlCl₃ and remains in contact with it for 5 hr. at room temperature.  On standing, 2 layers separate, the lower contains a heavy polymer bound chemically with the AlCl₃.  It is treated with NaOH and washed with H₂O, leaving a lubricating oil.  The upper layer contains paraffinic gasoline and free polymer, the former being removed by steam stripping, the remaining oil is clay-treated and filtered and a gas oil, a light lubricating oil for cold service, and a heavy lubricating oil suitable for ordinary lubrication is prepared.  The latter can be hydrogenated at 100 atm. and 200° over the normal Fischer-Tropsch catalyst to produce a substance similar to vaseline.  The above oils suffer from poor oiliness and ready oxidation.  Properties of 4 oils are given in a table.  The article concludes with a description of underground lubricating-oil plants.