Patent GB-689214-A (GB)
Title: Method of producing hydrocarbons
IPC: C07C1/04
Filed: 1951-01-12
Abstract: In the synthesis of hydrocarbons and, if desired, oxygenated derivatives, from CO and H2, using gas velocities of above 0.5 m./sec. (at 0 DEG  C. and 760 mm.), and catalyst layer thicknesses of more than 10 mm., a cooling medium of substantially constant boiling temperature is used, and the temperature difference between the catalyst and the cooling medium along the path of the gas through the catalyst is caused to vary continuously or in stages by increasing the cross-section of the catalyst layers in the direction of flow of the gas, by reducing the heat exchange surface in the direction of flow, and/or by reducing the heat transfer through the heat exchange surfaces in the direction of flow by insulating said surfaces.  The cooling medium may be water or, e.g., diphenyl, diphenyl oxide, hydrocarbons, silicones or mercury.  Reaction temperatures rising in the direction of flow are thus obtained with gas downflow using fixed catalysts or gas upflow with suspended catalysts.  Recycle of part or all of the unreacted gases may be used.  Catalyst tubes may contain conical or stepped tubes through which the cooling medium surrounding the catalyst tubes may also circulate.  Several lengths of tubing of different diameters and lengths may be welded to form a catalyst tube.  Welded ribs of decreasing height may be provided on the catalyst or cooling tubes.  In examples: (1) the reactor contains catalyst tubes of 6 m., with diameters of 20 and 40 mm. at top and bottom, respectively, the gas velocity corrected to 0 DEG  C. and 760 mm. being 13.3 m./sec. at the inlet and 3.55 at the outlet, and the corresponding reaction temperatures 243 DEG  and 263 DEG  C.; (2) the catalyst is in annular layers between the p  contact tubes and tapering, coaxial inner tubes to give a layer thickness varying from 15-25 mm.; gas velocities are 0.7-5 m./sec.; and temperatures 250-265 DEG  C.; (3) the catalyst tubes of 10 m. X 31 mm. are covered outside with an insulating layer, increasing from 1 mm. at the top to 4 mm. at the bottom, which may be a coating of enamel or the like or an annular space filled with gas or steam; (4) double tubes of 10 m. are used, the inner tubes being connected to the cooling medium supply and having longitudinal ribs of decreasing height in the downward direction. Specification 683,516 is referred to.  Reference has been directed by the Comptroller to Specification 690,925.ALSO:In the synthesis of hydrocarbons and, if desired, oxygenated derivatives, from CO and H2 using gas velocities of above 0.5 m./sec. (at 0 DEG C. and 760 mm.), and catalyst layer thicknesses of more than 10 mm., a cooling medium of substantially constant boiling temperature is used, and the temperature difference between the catalyst and the cooling medium along the path of the gas through the catalyst is caused to vary continuously or in stages by increasing the cross-section of the catalyst layers in the direction of flow of the gas, by reducing the heat-exchange surface in the direction of flow, and/or by reducing the heat transfer through the heat-exchange surfaces in the direction of flow by insulating said surfaces.  The cooling medium may be water or, e.g. diphenyl, diphenyl oxide, hydrocarbons, silicones or mercury.  Reaction temperatures rising in the direction of flow are thus obtained with gas downflow using fixed catalysts or gas up-flow with suspended catalysts.  Recycle of part or all of the unreacted gases may be used.  Catalyst tubes may contain conical or stepped tubes through which the cooling medium surrounding the catalysts tubes may also circulate.  Several lengths of tubing of different diameters and lengths may be welded to form a catalyst tube.  Welded ribs of decreasing height may be provided on the catalyst or cooling tubes.  In examples: (1) the reactor contains catalyst tubes of 6 m., with diameters of 20 and 40 mm. at top and bottom respectively, the gas velocity corrected to 0 DEG C and 760 mm. being 13.3 m./sec. at the inlet and 3.55 at the outlet, and the corresponding reaction temperatures 243 and 263 DEG C; (2) the catalyst is in annular layers between the contact tubes and tapering coaxial inner tubes to give a layer thickness varying from 15-25 mm.; gas velocities are .7-5 m./sec.; and temperatures 250-265 DEG C; (3) the catalyst tubes of 10 m. x 31 mm. are covered outside with an insulating layer, increasing from 1 mm. at the top to 4 mm. at the bottom, which may be a coating of enamel or the like or an annular space filled with gas or steam; (4) double tubes of 10 m. are used, the inner tubes being connected to the cooling medium supply and having longitudinal ribs of decreasing height in the downward direction. Specification 683,516 is referred to.  Reference has been directed by the Comptroller to Specification 690,925.