Abstract: A spent metal contaminated zeolite-containing catalytic cracking catalyst composition is reactivated by a process which comprises contacting with (a) dissolved lactic acid and either (b1) at least one dissolved calcium compound or, alternatively, (b2) at least one dissolved tin compound and at least one dissolved phosphorus compound.

Abstract: A spent metal-contaminated zeolite-containing catalytic cracking catalyst is reactivated by a process which comprises contacting the spent catalyst with at least one dissolved carboxylic acid and at least one antimony compound.

Abstract: A spent metal contaminated zeolite-containing catalytic cracking catalyst composition is reactivated by a process which comprises contacting with an aqueous solution of HC1 and/or HNO.sub.3 and/or H.sub.2 SO.sub.4. The thus reactivated catalyst composition can be employed in a catalytic cracking process.

Abstract: A spent metal contaminated zeolite-containing catalytic cracking catalyst composition is reactivated by a process which comprises contacting with an aqueous solution of at least one carboxylic acid (preferably at least one of formic acid, acetic acid, citric acid and lactic acid). The thus reactivated catalyst composition can be employed in a catalytic cracking process.

Abstract: A zeolite-containing catalytic cracking catalyst having been passivated by treatment with an aqueous solution which has been prepared by mixing an antimony oxide, ammonium bifluoride and water, at an atomic ratio of F:Sb in excess of about 6:1, is used in a process for catalytically cracking a hydrocarbon-containing feed, in particular one which contains metal impurities. In one embodiment, the above-described aqueous solution is injected into the feed. In other embodiments, the solution is injected into the cracking zone or into a catalyst regeneration zone.

Abstract: A process for reactivating a spent, metal-contaminated zeolite-containing catalytic cracking catalyst composition comprises partially demetallizing (preferably by chlorinating and washing) the spent catalytic cracking catalyst composition, and thereafter contacting it with at least one fluorine compound (preferably NH.sub.4 F) and at least one antimony compound. The thus reactivated catalytic cracking catalyst composition is employed in a catalytic cracking process.

Abstract: A process for reactivating a spent, metal-contaminated zeolite-containing cracking catalyst composition comprises the sequential steps of contacting the catalyst composition with dissolved ammonium compound (preferably NH.sub.4 NO.sub.3), contacting with a fluorine compound (preferably NH.sub.4 F), and treatment with a passivating agent (preferably Mg, Ca, B, A, P and/or Sb). The reactivated cracking catalyst obtained by this reactivation process is employed in a catalytic cracking process.

Abstract: A process for reactivating a spent, metal-contaminated zeolite-containing cracking catalyst composition comprises the substantially simultaneous contacting with a fluorine compound (preferably HH.sub.4 F) and a metals passivating agent (preferably a compound of Sb or Ca). The thus reactivated cracking catalyst composition is employed in a catalytic cracking process.

Abstract: Hydrocarbon-containing feed streams (preferably heavy gas oils and hydrotreated residua) having an initial boiling point of at least 400.degree. F. are catalytically cracked in the presence of a cracking catalyst comprising a faujasite-type zeolite having a unit cell size of about 24.28-24.48 A and an an alkali metal content of less than about 0.5 weight percent and being substantially free of iron ions. Preferably, the faujasite-type zeolite has an atomic Si:Al ratio in the crystalline framework of about 8:1 to 21:1 and has been partially dealuminated by a process comprising steam treatment followed by acid leaching.

Abstract: In a cracking process wherein used zeolitic catalyst is withdrawn from the cracking zone and treated with steam and then returned to the cracking zone, the improvement comprising diluting the steam with an organic compound.