GB803788A - Catalytic reforming of hydrocarbons and apparatus therefor - Google Patents

Abstract

803,788. Gas manufacture. GAS MACHINERY CO. April 11, 1956 [Jan. 23, 1956], No. 11009/56. Class 55 (2). Liquid or gaseous hydrocarbons are catalytically reformed in a pair of shells 31, 32 used alternately by reversal of flow and having a crossover 33 joining their tops, by first heating the catalyst bed 40 in one of the shells, say 31, by passing air upwardly through the bed 40 in the other shell 32 from the intake 53, the heated air being mixed with atomized liquid fuel and primary air from one or both of the burners 52 in its path between the beds 40, the combustion products passing through the passage 35 to the stack 44 ; then by passing a stream of a gaseous vehicle, steam being particularly mentioned, from the inlet 55 along the path of the air and introducing the hydrocarbon, from one or both nozzles 57, into the steam so that the mixture passes downwardly through the previously heated catalyst bed 40 ; and passing the products of the reaction through the conduits 43, 47 to a wash-box and storage reservoir. A heat run in the shell 32 then follows. The steam may, after the heating of the catalyst bed, be admitted, for a short time, without admixture with hydrocarbon, to purge air from both catalyst beds, the exhaust from the purging operation being passed to the stack 44 or to a waste-heat boiler connection 46. Also the flow of steam, without admixed hydrocarbon, is continued for a short time at the end of the make run, to react with carbon in the catalyst bed and restore the activity thereof. The carbon may be more completely removed by a brief passage downwardly, through the catalyst, of regenerative air from the other shell, the resulting C0 2 and N being exhausted to the stack or to the waste heat boiler. As shown, the beds 40 are supported on grills 39 carried by conventional regenerator checkerwork 38. In a modification, an upper checkerwork structure is arranged above each catalyst mass which is built up of closely packed columns of stacked star-sectioned elements 65, Fig. 6, of porous refractory ceramic materials impregnated, in known manner, with nickelous oxide. Reformed gas may be bled off from below the catalyst bed and reintroduced with the process steam to provide a more reducing atmosphere. Also the catalyst in the shell just subjected to a heat run may be reactivated by contact with reformed gas which is admitted at the bottom of the other shell. It is preferred to introduce all, or nearly all, of the fuel downwardly in countercurrent to the regenerative air rising in the shell which is not being subjected to the heat run. In this case the combustion is substantially completed before reaching the catalyst bed in the shell being heated, the bed being thus protected from impingement by hightemperature flames. The make oil, or most of it, is likewise directed downwardly in the regenerative shell, so that the steam and oil are thoroughly mixed in the cross-over, 33 before reaching the catalyst bed.