GB775815A - Regeneration of solid granular contact material - Google Patents

Abstract

In the regeneration of spent solid granular contact material containing a carbonaceous contaminent by burning with air, the contact material gravitates downwardly as a compact bed, air is introduced into the bed at a plurality of points uniformly distributed across the bed at a level intermediate the top and bottom of the bed and at least a portion of the air flows downwardly with the contact material and is removed as flue gas from the lower portion of the bed, and the distance between adjacent points of air introduction is less than 10 inches, preferably between 5 and 10 inches. As a result of the closeness of spacing of the air inlets, the temperature differences at <PICT:0775815/III/1> different points across the bed are levelled out more rapidly as the solid descends, and thus a more even regeneration takes place and the burning capacity of the regenerator is increased. As shown in Fig. 3, solids enter at 53 and pass down pipes 55, while air enters at 51, passing down pipes 56 to outlets 57; part of the air leaves at 59 and the remainder flows upward, leaving at 58. Cooling coils may be arranged just above the bottom of the bed. A distributer for use at the bottom of the air introduction pipes 56 comprises four pipes 67, Fig. 8, and a central pipe 68 provided with an orifice plate 69. An alternative form of distributer comprises a central vertical pipe 70, Fig. 11, an orifice plate 74, and a series of vertical slots in the pipe 70 communicating with triangular ears 71. The regeneration may form part of a continuous process for the cracking or hydroforming of hydrocarbons in which contact material gravitates as a compact bed through reaction and regeneration zones and is then transferred upwardly in a stream of lift gas to the top of the reaction zone. Specification 689,369 is referred to.