CATALYST REGENERATION PROCESS

摘要

1499682 Fluid catalytic cracking STANDARD OIL CO 4 March 1975 [4 March 1974] 8885/75 Heading C5E [Also in Division B1] In a cyclic catalytic hydrocarbon cracking process wherein deactivated catalyst is withdrawn from the reactor, stripped, regenerated and recycled to the reactor, the regeneration comprises (a) fluidizing the deactivated catalyst, in physical association with a carbon monoxide-oxidationpromoting catalyst of a metal of At No. of at least 20, with a molecular oxygen-containing gas so as to burn substantially all coke from the catalyst and convert substantially all of the carbon monoxide produced to carbon dioxide, most of the heat so produced being absorbed by the catalyst particles and the temperature being maintained at from 1000-1500‹ F.; and (b) withdrawing an effluent gas containing not more than 1À0 vol. per cent of carbon monoxide and regenerated cracking catalyst containing absorbed heat and having no more than 0À10 wt. per cent residual coke. The initial coke combustion and the carbon monoxide oxidation may be effected in a single dense phase bed or the former may be effected in a dense phase bed and the latter in a dilute phase bed. The oxidation catalyst may be metallic or oxidic and may contain Zn, Ce, U, Ti, Zr, Bi, Cr, Mo, W, Mn, Fe, platinum metals or heteropoly oxides. It may be present, either supported or unsupported, in physical admixture with the cracking catalyst or may be impregnated thereon. The cracking catalyst may be a crystalline aluminosilicate in a silicaalumina matrix. The cracking process may use a feed boiling above the gasoline boiling range, e.g. at 400-1200‹ F. such as light or heavy gas oils, wide-cut gas oils, vacuum gas oils, kerosenes, decanted oils, residual fractions, reduced crude oils or cycle oils derived from these or fractions from shale oil, tar sands processing, synthetic oils and coal hydrogenation. Suitably, cracking is effected exclusively in a 'riser' reactor at 950-1000‹ F. with a contact time of 3-10 secs., a throughput ratio of 1 to 2, and a catalyst to oil weight ratio of 2 to 10. Spent catalyst may be stripped at 850-1050‹ F. with steam, nitrogen or flue gas at 10-35 p.s.i.g.