Catalyst regeneration method
A process is disclosed for regenerating a used catalyst comprising two or more noble metals supported on a carrier. The method comprises calcining a used catalyst comprising a noble metal and a transition metal supported on an inorganic carrier in an oxygen-containing gas to produce a calcined catalyst; and contacting the calcined catalyst with a hydrogen-containing gas at a temperature higher than 430° C.
1 . A catalyst-regeneration method comprising (a) calcining a used catalyst comprising palladium and silver supported on an inorganic carrier in an oxygen-containing gas at a temperature of 350 to 1000° C. to produce a calcined catalyst; and (b) contacting the calcined catalyst with a hydrogen-containing gas at a temperature higher than 430° C.
2 . The method of claim 1 wherein the used catalyst comprises 0.001 to 2 wt % palladium.
3 . The method of claim 1 wherein the used catalyst comprises 0.1 to 5 wt % silver.
4 . (canceled)
5 . The method of claim 1 wherein step (b) is performed at a temperature in the range of 450 to 550° C.
6 . The method of claim 1 wherein the oxygen-containing gas comprises 10 to 50 mol % steam.
7 . The method of claim 1 wherein the hydrogen-containing gas comprise from 1.0 to 10 mole percent hydrogen
8 . The method of claim 1 wherein the inorganic carrier is selected from the group consisting of silica, alumina, zeolite, and mixtures thereof.
9 . The method of claim 1 wherein the inorganic carrier is alumina.
10 . (canceled)
11 . The method of claim 1 wherein the used catalyst is recovered from an acetylene hydrogenation process.
12 . The method of claim 1 wherein the used catalyst is recovered from a process for making hydrogen peroxide from hydrogen and oxygen.
13 . The method of claim 1 wherein the inorganic carrier is a transition metal zeolite.
14 . The method of claim 13 wherein the used catalyst is recovered from a process for making an epoxide from an olefin, hydrogen, and oxygen.
15 . The method of claim 14 wherein the olefin is propylene.