Abstract: A method of separating impurities from impure PO, the method comprising distilling impure PO in a distillation zone to provide distillate PO of enhanced purity, wherein heat is provided to the distillation zone by a bottoms reboiler and by an intermediate reboiler, the intermediate reboiler providing heat at a lower temperature than the bottoms reboiler. A suitable distillation system is also disclosed.

Abstract: A method of separating impurities from impure PO, the method comprising distilling impure PO in a distillation zone to provide distillate PO of enhanced purity, wherein heat is provided to the distillation zone by a bottoms reboiler and by an intermediate reboiler, the intermediate reboiler providing heat at a lower temperature than the bottoms reboiler. A suitable distillation system is also disclosed.

Abstract: A gas-liquid contacting tray suitable for horizontal mounting in a normally vertical column, which tray comprises a tray plate with substantially circular circumference and having top and bottom surfaces, which tray plate is provided with passages for gas between the bottom and the top surface, and on which tray plate two semi-circular tray sections are defined by a virtual diametrical line of the tray plate; and a total of three downcomers for guiding liquid from the top surface of the tray plate to below the tray, each downcomer extending from an inlet opening arranged in the tray plate to a downcomer outlet opening below the tray, wherein two of the downcomers are arranged in the corners of one of the semi-circular tray sections, and wherein the third downcomer is arranged on the other tray section substantially along a radius of the tray that is perpendicular to the diametrical line.

Abstract: Container suitable for preheating, retorting and cooling of shale under pressure comprising a vessel (2) and a primary stiffener system comprising side stiffeners (16, 17), a top stiffener (20) and a stiffener connecting system (21), wherein the primary stiffener system (11) prevents excess bending of the walls (3, 4, 7, 8) of the vessel (2), and wherein, when heated, the stiffener connecting system (21) forces the primary stiffener system (11) to give way so as to allow some expansion of the walls of the vessel (2).

Abstract: Process and apparatus for the combustion of coke present on solid particles from which hydrocarbons have been substantially removed by heating, and for the production of recoverable heat from hydrocarbon-bearing solid particles, in a series of at least two combustion stages.

Abstract: Hydrocarbons are extracted from a hydrocarbon-bearing substrate, e.g. shale oil, bituminous coal, tar sand, in the substantial absence of oxygen at temperatures above 400.degree. C., by passing substrate particles through a plurality of successive stages in which the substrate is mixed with a solid heat-bearing medium, the mixture being maintained in a fluidized-bed condition, and the liberated hydrocarbons being removed by passage of an inert stripping gas in cross-current flow with respect to the passage of the substrate particles. The average cross-sectional area of at least one or more of the stages subsequent to the first one is preferably smaller than the average cross-sectional area of one or more of the preceding stages.An apparatus for carrying out the process is described.

Abstract: Hydrocarbon-bearing substrate particles are pre-heated by heating the same with a solid heat-bearing medium by indirect counter-current flow using a series of heat transfer loops each containing a circulating heat transfer medium chosen such that the whole series permits a staged rise in temperature of the substrate particles and a staged drop in temperature of the solid heat-bearing medium. Preferably the heat transfer fluid in the loops circulates between the substrate and the hot spent substrate by means of the so-called thermosyphon effect.An apparatus for carrying out the method is described.