Patent GB-793924-A (GB)
Title: Hydroforming with dealkylation of recycle aromatics
IPC: C10G69/08
Filed: 1956-11-27
Abstract: <PICT:0793924/IV (b)/1> A catalytic reformate obtained by hydroforming a naphtha feed is distilled to separate into C8 and lighter hydrocarbons and C9 and heavier hydrocarbons, principally aromatics, which latter is subjected to thermal hydrodealkylating to C7 and C8 hydrocarbons and at least a portion of this is hydrofined and recycled to the hydroforming operation.  In a preferred embodiment the naphtha feed is first hydrofined in the hydrofiner 2 at 550-700 DEG  F., 100-500 p.s.i.g. in the presence of 200-1500 SCF/barrel of feed of a recycle gas containing 50-95 volume per cent hydrogen over a cobalt molybdate catalyst supported on alumina at a space velocity of 2-10 ft./sec.  Thence the feed is hydroformed, after separation of gases, in one or more reactors 7 and 11.  The feed is heated in furnaces 5 and 9 to 875-975 DEG  F. and is hydroformed at 100-700 p.s.i.g. in the presence of 2,000-10,000 SCF/barrel of feed of a recycle gas.  The catalyst employed may be in fixed or fluidized bed and is preferably platinum or palladium but may be molybdenum oxide, chromium oxide or tungsten oxide and is supported on activated alumina or zinc aluminate spinel.  The reformate is fractionated in the column 13 recycle gas being taken off by line 16, C4 and lighter by line 14, C5-C8 product (typically up to 290 DEG  F) by line 15 and C9+ (typically 290-350 DEG  F.) by line 17. Polymeric material may be discarded by line 18 or fed to the thermal dealkylation with the C9+ material in the zone 19. The dealkylation is performed at 1000-1200 DEG  F., 50-1200 p.s.i.g., at a space velocity of 0.2-5 vol./vol./hr., in the presence of 100-2000 SCF/barrel of feed of recycle gas.  The product is fractionated in column 21, recycle gas being taken off and recycled to the hydrofining or hydroforming steps by lines 28, 26 and 25, the main liquid fraction is recycled to the hydrofining zone by line 23 and tars are rejected.  The product has improved volatility over a standard hydroformate as indicated by an example.ALSO:<PICT:0793924/III/1> A catalytic reformate obtained by hydroforming a naphtha feed is distilled to separate into C8 and lighter hydrocarbons and C9 and heavier hydrocarbons, principally aromatics, which latter is subjected to thermal hydrodealkylating to C7 and C8 hydrocarbons and at least a portion of this is hydrofined and recycled to the hydroforming operation.  In a preferred embodiment the naphtha feed is first hydrofined in the hydrofiner 2 at 550-700 DEG  F., 100-500 p.s.i.g. in the presence of 200-1500 SCF/barrel of feed of a recycle gas containing 50-95 volume per cent hydrogen over a cobalt molybdate catalyst supported on alumina at a space velocity of 2-10 ft./sec.  Thence the feed is hydroformed, after separation of gases, in one or more reactors, 7 and 11.  The feed is heated in furnaces 5 and 9 to 875-975 DEG  F. and is hydroformed at 100-700 p.s.i.g. in the presence of 2,000-10,000 SCF/barrel of feed of a recycle gas.  The catalyst employed may be in fixed or fluidized bed and is preferably platinum or palladium but may be molybdenum oxide, chromium oxide or tungsten oxide and is supported on activated alumina or zinc aluminate spinel.  The reformate is fractionated in the column 13 recycle gas being taken off by line 16, C4 and lighter by line 14, C5-C8 product (typically up to 290 DEG  F.) by line 15 and C9 + (typically 290-350 DEG  F.) by line 17. Polymeric material may be discarded by line 18 or fed to the thermal dealkylation with the C9 + material in the zone 19. The dealkylation is performed at 1000-1200 DEG  F., 50-1200 p.s.i.g. at a space velocity of 0.2-5 vol./vol./hr., in the presence of 100-2000 SCF/barrel of feed of recycle gas.  The product is fractionated in column 21, recycle gas being taken off and recycled to the hydrofining or hydroforming steps by lines 28, 26 and 25, the main liquid fraction is recycled to the hydrofining zone by line 23 and tars are rejected.  The product has improved volatility over a standard hydroformate as indicated by an example.