Patent GB-305846-A (GB)
Title: Process of making lubricating oils
IPC: C10G71/00
Filed: 1928-03-07
Abstract: 305,846. Jackson, L. Mellersh-, (Sun Oil Co.). March 7, 1928. Hydrocarbons, distilling.- Lubricating oils of low carbon content and organic acidity, good colour and demulsibility, and high flash and fire tests are produced by distilling lubricating stock from crude oil, e.g. an asphalt base oil, in a system closed against oxygen, passing the lubricating stock through a series of vaporizers in which it is distributed over extended surfaces and brought into heat exchange with mercury vapours in such a way as to avoid cracking, progressively higher boiling lubricating fractions being separated in successive vaporizers, and finally removing odour producing gases by subjecting the separate distillates to reflux condensation under vacuum and thereafter causing the oil to flow under very high vacuum in a shallow turbulent stream over extended surfaces. In the apparatus shown crude oil enters settling tanks c, which are used in rotation, through a pipe line a and is warmed by one or more heat exchangers b. The oil thus freed from water passes through a pipe still d heated e.g. by mercury vapour to avoid cracking, and if desired under reduced pressure, and into a tower divided into two or more sections e, f, uncondensed vapours, e.g. gasoline, passing from the top through a condenser g partly to storage and partly back to the tower, a middle fraction, e.g. gas oil, passing partly to storage through a line k and partly back to the tower, and a heavy fraction, containing e.g. heavy gas oil, passing to a tank o, where it is mixed with aqueous caustic soda &c. to neutralize acids, water vapour and volatile oils passing into a fractionating tower t, oil being returned if desired to tank o through a line v, a line w leading to storage. The dehydrated oil containing caustic soda in suspension passes into a still z, where it is distilled under reduced pressure, the application of heat being in some cases unnecessary, lighter products passing into a reflux condenser 11, whence they pass either to a storage tank 16, a second connection passing through the base of the reflux condenser as shown and leading to a storage.tank 19. The residual oil or lubricating stock flows from still through a line 17 to a lubricating oil distillation plant, where a series of vaporizers, e.g. ten in number, are used constructed as ' shown in Fig. 2, mercury vapour being passed into a, compartment 24 while oil distils from a compartment 23 through pipes 25, from each of which the condensate may, if desired, be separately taken. The mercury may be replaced by other volatile metals or alloys or diphenyl oxide, benzophenone, or sulphur. The residue from the last vaporizer passes to a tank 27. The mercury vapour chambers are fed from a mercury boiler 30, mercury condensates returning via cups 34 to the boiler. The condensation of the distillates from the vaporizers takes place in towers 42 containing Raschig rings &c., the desired fraction being led off through pipes 50 through a deodorizer 50 containing staggered plates 51 over which the oil flows in a shallow turbulent stream under high vacuum. The most volatile constituent flows from the top of the tower 42 to a stink oil receiver 49. Specification 230,821 is referred to.