METHOD OF PARTIAL DEALUMINATION OF ZEOLITE CATALYST Russian patent published in 1997 - IPC

FIELD: zeolite catalysts. SUBSTANCE: method of partial dealumination of zeolite catalyst by treating it with live steam consists in feeding steam into and passing it through reactor with zeolite catalyst bed to provide steam-catalyst contact for 0.1 to 50 h under temperature distribution conditions which meet the following requirements: (1) 500^°C≅T_o≅T≅T₂≅700^°C where T_o is temperature of fed steam (oC), T₂ maximum temperature of catalyst bed, and t average temperature of catalyst bed determined from equation: T = , in which T_i is time-mean temperature of i-th block of n equivalent blocks composing catalyst bed and arranged along steam stream direction; and (2) cV(T) x 1000 ≅ 10 where cV(T) is coefficient of deviation from time-mean temperature according to equation: cV(T) = S(T)/T in which S(T) is standard deviation of time- mean temperature derived from expression S(T)² which is deviation of time-mean temperature and may be found from formula: in which T and T_i are such as defined above. EFFECT: optimized synthesis parameters. 15 cl, 3 dwg , 4 tbl