GB1073727A - Method of reacting a gas and a liquid - Google Patents

Abstract

<FORM:1073727/C4-C5/1> A gaseous reactant and a slurry comprising a liquid reactant and a finely-divided catalyst are passed upwards through a mass of particulate solids in reactor 9, thereby expanding the mass by at least 10% in volume. A major proportion of the slurry is recycled from above the upper level 12 of the expanded mass, by internal standpipe 30 and pump 32. Effluent from the reaction is separated at 16 into a gaseous phase, containing gaseous reactant and reaction products, and a slurry phase, from which catalyst is recovered at 22, optionally regenerated, and returned to the mixer 2. Surplus reactant may also be recovered from the line 17 and returned to inlet 5. Alternatively the separator 16 may be dispensed with, gaseous and slurry phases being withdrawn from different ports at the top of reactor 9. Screen 13 prevents particulate solids leaving reactor 9, but alternatively the reactor may widen at the top to reduce the upward velocity. The particulate solids may be inert Al2O3, SiC, glass, quartz, slag or fireclay pellets of 1/32 to 1/2 inch diameter. Alternatively, they may be catalysts, identical to or different from the slurry catalyst, or ion exchange resin or zeolite adsorbent, whereby some reaction product is removed from the reactor, e.g. by a regeneration line 26, 27. In hydro-desulphurization of heavy oils the particulate solids may be a cracking catalyst (clay or silica gel) and the slurry comprises a hydrogenation catalyst (95% iron oxide, 5% chromium oxide). In partial hydrogenation of fats and oils a slurry of nickel catalyst is passed through pellets of nickel catalyst.ALSO:<PICT:1073727/C2/1> A gaseous reactant and a slurry comprising a liquid reactant and a finely divided catalyst are passed upwards through a mass of particulate solids in reactor 9, thereby expanding the mass by at least 10% in volume. A major proportion of the slurry is recycled from above the upper level 12 of the expanded mass, by internal standpipe 30 and pump 32. Effluent from the reaction is separated at 16 into a gaseous phase, containing gaseous reactant and reaction products, and a slurry phase, from which catalyst is recovered at 22, optionally regenerated, and returned to the mixer 2. Surplus reactant may also be recovered from the line 17 and returned to inlet 5. Alternatively the separator 16 may be dispensed with, gaseous and slurry phases being withdrawn from different ports at the top of reactor 9. Screen 13 prevents particulate solids leaving reactor 9, but alternatively the reactor may widen at the top to reduce the upward velocity. The particulate solids may be inert Al2O3, SiC, glass, quartz, slag or fireclay pellets of 1/32 to 1/2 inch diameter. Alternatively they may be catalysts, identical to or different from the slurry catalyst, or ion exchange resin or zeolite adsorbent, whereby some reaction produce is removed from the reactor, e.g. by a regeneration line 26, 27. Reactions mentioned are hydrogenation of aldehydes and ketones using a zinc, copper or cadmium chromite catalyst to produce alcohols; production of aniline by reacting gaseous NH3 with a slurry of cuprous oxide in chlorobenzene; chlorination of benzene to produce chlorobenzene using ferric chloride catalyst; oxidation of naphthalene or anthracene to phthalic anhydride or anthraquinone respectively, with air, using a vanadium oxide catalyst; and esterification by contacting ethanol vapour with a slurry of molten maleic anhydride and zirconium oxide catalyst.