GB558984A - Improvements in or relating to the control of the catalyst-oil ratio in the catalytic cracking of hydrocarbon oils - Google Patents

Abstract

558,984. Catalytic conversion of hydrocarbon oils. INTERNATIONAL CATALYTIC OIL PROCESSES CORPORATION. May 8,1942, No. 6252. Convention date, May 9, 1941. [Classes 1 (i) and 32] [Also in Group XXIX] In processes for the catalytic cracking of hydrocarbon oils of the kind in which a suspension of oil vapours and catalyst is passed through a heated reaction zone, the ratio of vapours to catalyst in the suspension is maintained constant by passing the suspension through a Venturi nozzle or like orifice at which a pressure differential is developed and utilizing departures 'from the pre-arranged pressure differential to control the supply of catalyst to the catalyst and oil mixing chamber. The hydrocarbon stock is vaporized in a coil 14 and mixed in an injector chamber 22 with catalyst recycled from a hopper 98 through a line 24 controlled by a valve 36. The suspension passes to a reaction chamber 28 and thence through a line 32 provided with a Venturi nozzle 34 at which point a pressure differential is developed which is utilized to operate the valve 36 through a control circuit as shown in Fig. 2, [see Group XXIX]. The cracked vapours pass through a separator 38 from which catalyst is removed and passed by an injector 52 and line 56 to a collecting chamber 62 where further separation of vapours is effected, the combined vapours passing to fractionating and recovery plant through line 70. The catalyst falls through a stand pipe 72 where it is aerated by steam &c. supplied through lines 74, 76, 78, 82 and is then mixed with oxidizing gases from a line 86 and fed to a regenerator 92 the regenerated catalyst passing through a further separator 96 to a feed hopper 98 provided with a stand pipe 24 supplied with steam through manifold 106 and spaced points 108, 110, 112. Part of the catalyst may be passed through a by-pass 114 and lines 134, 136 with or without heating in coil 132 to mix with the catalyst passing to the regenerator 92 thus controlling the temperature in the regeneration zone and preventing it from rising above 1200‹F.