A process for regenerating a dehydrogenation catalyst comprises the steps (a)-(f):
(a) flushing with inert gas at a pressure of from 0.5 to 2.0 bar and a gas
hourly velocity of from 1000 to 50 000 h-;1;
(b) passing an oxygen-containing gas mixture comprising an inert gas through
the catalyst at a pressure of from 2 to 20 bar and a gas hourly velocity of from
1000 to 50 000 h-;1 for from 0.25 to 24 hours while increasing the oxygen
concentration stepwise or continuously from an initial value of from 0.01 to 1%
by volume of O2 to a final value of from 10 to 25% by volume of O2;
(c) optionally passing an oxygen-containing gas mixture comprising an inert
gas through the catalyst at a pressure of from 0.5 to 20 bar and a gas hourly velocity
of from 10 to 500 h-;1 for from 0.25 to 100 h, with the oxygen concentration
being from 10 to 25% by volume of O2;
(d) optionally changing the pressure repeatedly, rapidly and in opposite
directions by a factor of from 2 to 20 within the range from 0.5 to 20 bar;
(e) flushing with an inert gas;
(f) activating the catalyst by means of hydrogen;
- where at least one of the steps (c) or (d) is carried out and the entire
regeneration process is carried out at from 300 to 800 C.
