Patent GB-745283-A (GB)
Title: Improvements in or relating to methods for hydroforming hydrocarbons
IPC: B01J23/96
Filed: 1951-11-07
Abstract: <PICT:0745283/IV(a)/1> In the hydroforming of hydrocarbons at a temperature below 975 DEG  F. and a pressure below 500 lbs. per sq. inch in the presence of a platinum or palladium catalyst supported on an alumina-containing base, the catalyst is used for not more than 12 hours and is then reactivated by treatment with a hydrogen-containing gas in the absence of hydrocarbons in order to remove coke and carbonaceous deposits.  The process may be carried out with a single fixed or fluidized bed of catalyst, or with a plurality of beds, each bed being used for hydroforming and reactivated alternately; in another process powdered catalyst is circulated between hydroforming and reactivation zones.  Hydroforming preferably takes place at a temperature of 800-975 DEG  F. and a pressure of 50-500 lbs. per sq. inch for a period not exceeding 3 hours. Reactivation may be effected at 50-200 DEG  F. higher than hydroforming and for a period 1-10 times as long; longer reactivation periods may be attained by using correspondingly larger amounts of catalyst in the reactivation zone with the same rate of gas flow.  Reactivation is preferably carried out with the gas from the reaction zone after separation of the hydroformed products; this gas may be heated to 1000-1400 DEG  F.  As shown, a naphtha fraction introduced at 32 is mixed with catalyst entrained in hydrogen-containing gas from the reactivation zone 14, and is hydroformed in zone 12, catalyst returning via downcomer 16 to the reactivation zone.  The reaction products pass through condenser 56, liquid being removed through line 62, and the gas returned to the reactivation zone, via heater 74 if desired.  In an alternative process (Fig. 2, not shown), hydroforming and reactivation are carried out in separate vessels, each containing a fluidized bed of catalyst, and the catalyst is removed from the base of each vessel through a standpipe and carried to the other vessel in a gaseous stream.  Reference is also made to gravity flow of the catalyst from the reactor to the reactivator.ALSO:<PICT:0745283/III/1> In the hydroforming of hydrocarbons at a temperature below 975 DEG F. and a pressure below 500 lbs. per sq. in. in the presence of a platinum or palladium catalyst supported on an alumina-containing base, the catalyst is used for not more than 12 hours and is then reactivated by treatment with a hydrogen-containing gas in the absence of hydrocarbons in order to remove coke and carbonaceous deposits.  The process may be carried out with a single fixed or fluidized bed of catalyst, or with a plurality of beds, each bed being used for hydroforming and reactivated alternately; in another process powdered catalyst is circulated between hydroforming and reactivation zones. Hydroforming preferably takes place at a temperature of 800 DEG -975 DEG F. and a pressure of 50-500 lbs. per sq. in. for a period not exceeding three hours. Reactivation may be effected at 50 DEG -200 DEG F. higher than hydroforming and for a period 1-10 times as long; longer reactivation periods may be attained by using correspondingly larger amounts of catalyst in the reactivation zone with the same rate of gas flow.  Reactivation is preferably carried out with the gas from the reaction zone after separation of the hydroformed products this gas may be heated to 1000 DEG -1400 DEG F.  As shown, a naphtha fraction introduced at 32 is mixed with catalyst entrained in hydrogen-containing gas from the reactivation zone 14 and is hydroformed in zone 12, catalyst returning via downcomer 16 to the reactivation zone.  The reaction products pass through condenser 56, liquid being removed through line 62, and the gases returnd to the reactivation zone, via heater 74 if desired.  In an alternative process (Fig. 2, not shown), hydroforming and reactivation are carried out in separate vessels, each containing a fluidized bed of catalyst, and the catalyst is removed from the base of each vessel through a standpipe and carried to the other vessel in a gaseous stream. Reference is also made to gravity flow of the catalyst from the reactor to the reactivator.  The catalyst may be prepared as described in Specification 745,284 by mixing dried activated alumina with an aqueous solution of hydrogen fluoride to form a paste, allowing to stand, drying and mixing with an aqueous solution of chloroplatinic acid to a paste, bubbling hydrogen sulphide through the paste to precipitate platinum, and then drying and calcining; the preferred catalyst contains 0.1-1 per cent platinum and 0.5-1 per cent hydrogen fluoride, and the alumina support may contain a small proportion of silica.