Patent GB-527307-A (GB)
Title: An improved method of and apparatus for converting hydrocarbon oils
Filed: 1939-04-01
Abstract: 527,307. Cracking oils ; catalysts ; polymerizing hydrocarbons. KELLOGG CO., M. W. April 1, 1939, No. 10275. Convention date, April 2, 1938. [Classes 1 (i) and 32] [Also in Group IV] In the continuous catalytic conversion of hydrocarbons in the vapour phase the vapours heated to reactive temperature are passed continuously through a reaction zone through which a compact bed of catalyst is flowed under gravity, the catalyst being continuously withdrawn, reactivated, and returned to the reaction zone. The catalytic conversion may comprise cracking polymerization, dehydrogenation or synthetic reactions. Oil from tank 1 is fed through preheater 4 and optionally through fractionating tower 6 to a vaporizing coil 15 where it is heated to 750- 950‹F. and passed into a separator 18 from which heavy residues are removed through line 25 with partial recycling through line 28. The vapours are passed through heating coils 34 where they are raised to 900-1,000‹F. and then passed into reaction chamber 39. The coils 34 may be byepassed by the valve 44. The vapours, after passage upwardly through the reactor, are led off through line 45 and heat-exchanger 4 to fractionating tower 6 from which reflux is taken off through line 78 and heat-exchanger 74 and is recycled through line 80 or fed through line 19 as reflux to separator 18. Vapours pass off through line 46 and cooler 47 and the condensate is separated from gases in receiver 50 and recycled in part as reflux to tower 6 the remainder being fed through lines 60, 63, 64 into the combined stabilizer and absorption tower 68, 89. The gases removed from separator 50 are compressed and cooled and the residual condensible components separated in receiver 59 the gases being passed through 67 into the absorber section 68 and the condensate into the stabilizer section through line 66. Rich fractions are stripped from the gases in the absorber section 68 by circulating as absorption medium condensate from the bottom of the stripping zone 72 through line 103 to the top of the tower, the enriched oil being withdrawn through line 71 and returned to the zone 72 where it is stripped by circulation through heat exchanger 74. The released vapours are passed into the stabilizer section 89 where fractionation is controlled to remove light fractions (which are passed through line 96 to section 68) by withdrawing reflux and recycling it through cooler 91 and by withdrawing condensate from lower tray and recycling it through heat exchanger 98 and stabilized gasoline is withdrawn through line 104. The catalyst is fed through the reaction chamber from a conveyer 111 to a hopper 110 provided with cone type valve 114 operated hydraulically, the catalyst passing first through a sealing hopper 117 and after leaving the reaction chamber through a similar sealing hopper 123. The catalyst is maintained under pressure by means of inert gas fed through lines 132, 133, 137, 140, the gas also serving to remove vapours from the used catalyst which is then fed through conveyer 143 to the regeneration chamber. This latter, Fig. 2, comprises a rotary retort 154 to which the used catalyst is fed by conveyer 147 and from which it is withdrawn after revivification through hopper 195. The revivification is carried out by circulating flue gases through a separator 165 a flue gas steam generator 175 and the chamber 154 air for oxidation being supplied through line 149 and part of the flue gas removed through lines 182, 185, 132 as pressure agent for feeding catalyst through the reactor. A modification is described in which the revivification is carried out in a vertical regeneration chamber. The catalytic reaction chamber, Fig. 4, may comprise upper and lower chambers 235, 236 connected bv tubes 240 and a central passage 237 baffles 238, 239 being provided to direct the flow of catalyst and the catalyst being heated by circulating hot combustion gases or mercury vapours around the tubes 237, 240.