Patent GB-748075-A (GB)
Title: Improvements in or relating to the hydroforming of naphthas
IPC: C10G35/14
Filed: 1952-04-22
Abstract: In a continuous process for hydroforming naphtha in a zone containing a mass of mobile, finely-divided hydroforming catalyst comprising platinum and/or palladium on a carrier, the reaction is effected under such conditions, including a pressure below 500 p.s.i.g., as will result in relatively rapid contamination of the catalyst, i.e. in less than 400 hours, by deposition of carbon, and the activity is maintained by continuously withdrawing contaminated catalyst from the reaction zone, regenerating it by treatment with a free oxygen-containing gas in a regeneration zone, and returning it continuously to the hydroforming zone.  The hydrocarbon feed and hydrogen are separately preheated and fed to a reactor containing fluidized catalyst comprising 0.1-0.5 wt. per cent Pt or Pd on alumina, 0.5-2 wt. per cent HF also being maintained present.  The alumina may be made from aluminium alcoholate and may contain 3-10 per cent of silica.  Pressure is preferably at least 150 p.s.i.g. and temperature 875-950 DEG  F., 1000-5000 c. ft., 80-90 per cent H2 being fed per barrel of oil.  The product is freed from catalyst, hydrogen separated and recycled, and fractionated to recover hydroformate, heavy constituents being recycled.  Catalyst is withdrawn by a standpipe from near the base of the reactor, inert gas such as steam being injected to assist in transfer to a fluidized type regenerator where air or other oxygen-containing gas, preferably containing 2-6 per cent of oxygen, is injected.  Regenerated catalyst is withdrawn and fed to the recycle gas stream to the reactor. Regeneration may be complete or partial, the latter giving a regenerated catalyst containing more than 0.3 but not more than 1 per cent carbon by weight.  With such partial regeneration, high catalyst : oil ratios of 3-5 : 1 may be used and the heat of the regenerated catalyst, which may be increased by feeding extraneous fuel to the regenerator which may operate at up to 1100 DEG  F., allows of a decrease in the inlet temperature of the naphtha and hydrogen feeds. Pressure on the catalyst withdrawn from the reactor may be reduced and air regeneration effected at near atmospheric pressure. Deaeration of the catalyst may be effected by conducting it through a U-bend transfer line to a hopper where gas disengages and returns to the regenerator above the dense phase while solids flow by gravity to the reactor. Specifications 657,565 and 716,505 are referred to.ALSO:In a continuous process for hydroforming naphtha in a zone containing a mass of mobile. finely-divided hydroforming catalysts comprising platinum and/or palladium on a carrier, the reaction is effected under such conditions, including a pressure below 500 ps.i.g., as will result in relatively rapid contamination of the catalyst, i.e. in less than 400 hours, by deposition of carbon, and the activity is maintained by continuously withdrawng contaminated catalyst from the reaction zone, regenerating it by treatment with a free oxygen-containing gas in a regeneration zone, and returning it continuously to the hydroforming zone.  The hydrocarbon feed and hydrogen are separately preheated and fed to a reactor containing fluidized catalyst comprising .1-.5 wt. per cent Pt or Pd on alumina, .5-2 wt. per cent HF also being maintained present.  The alumina may be made from aluminium alcoholate and may contain 3-10 per cent of silica.  Pressure is preferably at least 150 p.s.i.g. and temperature 875-950 DEG F., 1000-5000 c. ft. 80-90 per cent H2 being fed per barrel of oil.  The product is freed from catalyst, hydrogen separated and recycled, and fractionated to recover hydroformate, heavy constituents being recycled.  Catalyst is withdrawn by a standpipe from near the base of the reactor, inert gas such as steam being injected to assist in transfer to a fluidized type regenerator where air or other oxygencontaining gas, preferably containing 2-6 per cent of oxygen, is injected.  Regenerated catalyst is withdrawn and fed to the recycle gas stream to the reactor.  Regeneration may be complete or partial, the latter giving a regenerated catalyst containing more than 0.3 but not more than 1 per cent carbon by weight.  With such partial regeneration, high catalyst: oil ratios of 3-5:1 may be used and the heat of the regenerated catalyst, which may be increased by feeding extraneous fuel to the regenerator which may operate at up to 1100 DEG F., allows of a decrease in the inlet temperature of the naphtha and hydrogen feeds.  Pressure on the catalyst withdrawn from the reactor may be reduced and air regeneration effected at near atmospheric pressure.  Deaeration of the catalyst may be effected by conducting it through a U-bend transfer line to a hopper where gas disengages and returns to the regenerator above the dense phase while solids flow by gravity to he reactor. Specifications 657,565 and 716,505 are referred to.