Abstract: A process for catalytic two-stage hydrodesulfurization of metal-containing petroleum residua feedstocks to achieve at least about 75% desulfurization of the liquid product while also providing at least about 40% reduction in catalyst consumption. In the process, used catalyst having a catalyst equilibrium age of 0.3-5.0 bbl oil feed/lb catalyst is withdrawn from the second stage reactor, rejuvenated so as to remove 10-50 wt. % of the contaminant metals and at least 80 wt. % of carbon deposited on the catalyst, and then cascaded forward and added to the first stage reactor. Sufficient fresh make-up catalyst is added to the second stage reactor to replace the used catalyst withdrawn there, and only sufficient fresh catalyst is added to the first stage reactor to replace any catalyst transfer losses. Used catalyst having a catalyst equilibrium age of 0.6 to 10.0 bbl. oil per lb. catalyst is withdrawn from the first stage reactor for discard.

Abstract: A process and apparatus for rejuvenating particulate used catalysts in a single rejuvenation vessel and providing a rejuvenated catalyst material having properties that result in activity substantially equal to new catalyst. The pressurizable vertically-oriented vessel has inlet and outlet openings for the catalyst and washing liquids, and is arranged to facilitate successive solvent liquid washing, water washings, and acid treatment steps for the used particulate catalyst provided in a bed in the vessel conical-shaped lower portion which contains catalyst rotary stirring means. After rejuvenation of the used catalyst, it is withdrawn from the vessel conical-shaped lower portion downwardly through a central withdrawal conduit and control valve for further processing. The water-soluble solvent and acid treatment liquids can be usually recovered by distillation for reuse in the catalyst rejuvenation process.

Abstract: Attapulgus clay rendered substantially non-swelling and non-gelling by calcination is treated with a large organophilic quaternary ammonium or phosphonium compound to yield a sorbent material effective for purifying liquids from inorganic and organic contaminants. Treatment of the mineral substrate may be accomplished by mixing in a liquid system or by spraying a solution of the quaternary ammonium surfactant onto the mineral. Surfactant on the mineral is present in quantities approximating the exchange capacity of the mineral.

Abstract: Attapulgus clay rendered substantially non-swelling and non-gelling by calcination is treated with a large organophilic quaternary ammonium or phosphonium compound to yield a sorbent material effective for purifying liquids from inorganic and organic contaminants. Treatment of the mineral substrate may be accomplished by mixing in a liquid system or by spraying a solution of the quaternary ammonium surfactant onto the mineral. Surfactant on the mineral is present in quantities approximating the exchange capacity of the mineral.