Exxon Research and Engineering Company

Raam R Mohan

Gopal H Singhal

Bernard G Silbernagel

Max Leo Robbins

Allen I Laskin

David E Allan

Lars A Naslund

Byron V Molstedt

A tungsten-containing catalyst associated with coke containing vanadium and nickel is recovered by a method which includes steam gasification, low temperature burning to remove at least a portion of the coke and selective extraction of the nickel and vanadium.

Method for the recovery of a tungsten-containing catalyst from coke

Contacting deactivated hydrodesulfurization catalyst, such as Co-Mo supported on alumina, with a heteropoly acid, such as molybdophosphoric acid or tungstosilicic acid, in pH range of about 1 to 3 and temperature range of about 20.degree. to 80.degree. C., results, before any coke is burned off the catalyst, in selective abstraction of vanadium and nickel, removal of sulfur, increase in surface area, and increase in pore volume of the catalyst. Subsequent cobalt doping of demetallized catalyst followed by calcination promotes decoking, additional sulfur removal and additional increase in surface area and pore volume. The process results in substantially complete regeneration of catalytic activity.

Regeneration of spent hydrodesulfurization catalyst with heteropoly acids

The removal of metals, especially vanadium, from spent hydrofining catalyst is accomplished by a two-step process. Treatment with a gaseous sulfur-containing reagent brings the metals to the surface of the catalyst and converts them to sulfides, which are then efficiently removed by contact with a heteropoly acid such as molybdophosphoric acid. Treatment of deactivated hydrodesulfurization catalysts such as Co-Mo supported on alumina by this process results in substantially complete regeneration of catalytic activity.

Regeneration of spent hydrodesulfurization catalysts employing

Contacting deactivated hydrodesulfurization catalyst, such as Co-Mo supported on alumina, with a heteropoly acid, such as molybdophosphoric acid or tungstosilicic acid, to which dilute hydrogen peroxide is added, results in a significant enhancement in the rate and extent of carbon and metals removal. Forms of deposited vanadium intractable by other treatments are also removed. The process results in substantially complete regeneration of catalytic activity.

Regeneration of spent hydrodesulfurization catalysts with heteropoly

A method of preparation and application of a composition comprising specified microorganisms in combination with surfactants for a synergistic dispersal of oil slicks.

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Berkley Heights, NJ, United States of America

Raam R Mohan