| 摘要 |
<p>Zeolitic catalysts contg. a hydrogenating metal are regenerated as follows: after use in hydrocarbon conversions, esp. hydrocracking. (i) the coke is burnt off at a temp. of 300-600 deg.C in an inert gas with an increasing proportion of O2; (ii) after cooling to a temp. of 0-250 deg.C, the catalyst is hydrated by treating with water vapour; (iii) after purging, the catalyst is treated with H2 at increasing temps. in the range 150-600 deg.C. In a heavily deactivated catalyst, (i) and (ii) may be sepd. by (ia) treatment with NH3 vapour to dissolve and disperse the metal. The zeolite is pref. a zeolite Y or mordenite (both with replacement of most of the alkali ions with H(+), alkaline earth or rare earth), erionite, offretite, ZSM 5 or ZSM 11. It pref. contains a Gp. Ib, IIb or VIII metal, esp. Ni, Pd and Pt. Inclusion of (ii) gives a catalyst of improved performance, and esp. stability.</p> |
