| 摘要 |
<p>Processes described include reacting a fresh or spent catalyst, or sorbent, with a solution containing an extracting agent (such as an acid or a base). Preferably, the catalyst contains both alumina and a molecular sieve (or a sorbent), and the reaction is performed under relatively mild conditions. Thus, the catalyst can be re-used and in certain instances the catalyst performance even improves. Additionally, metals contained in the catalyst, such as Na, Mg, Al, P, S, CI, K, Ca, V, Fe, Ni, Cu, Zn, Sr, Zn Sb, Ba, Pb, or their equivalent oxides, can be removed from the catalyst. Some of the metals that are removed are relatively valuable (such as the rare earth elements of La, Ce, Pr and Nd).</p> |
