GB825675A - Improvements in or relating to the oxidation of hydrocarbons - Google Patents

Abstract

<PICT:0825675/III/1> A process of partially oxidizing hydrocarbons is performed as described in the Specification 772,680 at temperatures of 500-750 DEG C., the temperature being controlled by cool finely divided inert solids rained down through the reaction zone through grids in an apparatus as illustrated. The solid, which may be siliceous or aluminiferous such as Ottawa sand, glass beads, spent clays, quartz, fused alumina, mullite or coke of size 50-2000 microns in diameter, is in fluidized beds 6 and 7 and is allowed to "rain" from the upper bed through the valves 8, grid 12 and reaction chamber 13 to the lower bed. It is lifted back by a lift gas which is preferably injected partly as liquid which is vaporized thereby cooling the solid, such as steam. Cooling coils may also be used to cool the solid. The solid is fed to the reaction zone at a rate of 5-50 pounds per pound of feed. The organic feed is introduced above the lower bed or if desired partially or wholly through the lower bed and oxygen is introduced at a number of points in the reaction zone by coils having a large number of holes on their underside. The local mol. ratio of oxygen to feed may be 0.1-0.5 with an overall ratio of 0.5-5. The product and lift fluid are combined and the product recovered. In a modification, the solid may be passed concurrently with the gaseous flow. Pressures of 0-200 p.s.i.g. can be used with gas flows of 0.5-10 ft/sec. Specification 772,680 is referred to.ALSO:<PICT:0825675/IV (b)/1> Olefines, epoxides and carbonyl compounds are produced by oxidizing C2+ hydrocarbons, at least 30% of the carbon atoms of which are in the form of methylenic groups, by mixing in the vapour phase with an oxygen-containing gas, passing through a reaction zone at 500-750 DEG C. with a residence time of not more than 20 seconds and keeping the temperature below the upper limit by passing cool finely-divided inert solids through the reaction zone which solids are rained down through the reaction zone and are present in amounts of 0.05-10 volume per cent of the reaction space. The solids are preferably rained down partly free and partly restrictively as described in Specification 772,680. The starting material may be a straight-chain or naphthenic hydrocarbon of 2-30 carbon atoms or mixtures ranging in boiling-point from - 20 DEG to 450 DEG C.; higher boiling compounds can be used in the presence of steam. The products are more unsaturated compounds but some oxygen-containing groups such as carbonyl compounds and epoxides are formed, considerable cracking also occurs with large molecules. The process is preferably performed in an apparatus as illustrated. The solid, which may be siliceous or aluminiferous such as Ottawa sand, glass beads, spent clays, quartz, fused alumina, mullite or coke of size 50-2000 microns in diameter, is in fluidized beds 6 and 7 and is allowed to "rain" from the upper bed through the valves 8, grid 12 and reaction chamber 13 to the lower bed. It is lifted back by a lift gas, which is preferably injected partly as liquid which is vaporized, thereby cooling the solid, such as steam. Cooling coils may also be used to cool the solid. The solid is fed to the reaction zone at a rate of 5-50 pounds per pound of feed. The organic feed is introduced above the lower bed or if desired partially or wholly through the lower bed and oxygen is introduced at a number of points in the reaction zone by coils having a large number of holes on their underside. The local mol. ratio of oxygen to feed may be 0.1-0.5 with an overall ratio of 0.5-5. The produce and lift fluid are combined and the product recovered. In a modification, the solid may be passed concurrently with the gaseous flow. Pressures of 0-200 p.s.i.g. can be used with gas flows of 0.5-10 ft./sec. In the examples: (1) hexane is oxidized to give principally C1-C3 olefines, some higher olefines, some liquid oxygenated compounds (C6 epoxides plus carbonyl and hydroxyl compounds), methane and carbon oxides; (2)(a) ethane gave ethylene; (b) propane gave propylene and ethylene; and (c) butane gave mostly butenes and ethylene; in each case some carbon oxides were also produced; (3) cetane gave principally olefines and diolefines with a small amount of oxygenated compounds including C2-C4 carbonyls and epoxides of less than 16 carbon atoms and some carbon oxides; (4) a gas oil gave largely C2-C21 olefines and methane (59.2% based on feed reacted), some carbon oxides (14%) and oxygenated compounds (31.1%) including some acetaldehyde and p methanol, about half being carbonyls and the remaining half epoxides; (5) cyclohexane is converted to cyclic C6 olefines and diolefines and some benzene, C2-C5 straight-chain olefines and diolefines and various oxy-compounds including formaldehyde, acetaldehyde and 1,4-epoxy cyclohexane; octene-2 gave considerable amounts of C4 and higher diolefines together with other olefines including ethylene and octadienes and some oxygenated compounds; (6) an Arabian naphtha and a hydroformed naphtha are converted to naphthas of increased olefine content as well as producing valuable olefinic gas; (7) a normally solid petrolatum is cracked to give mainly liquid products and some gaseous olefines.