ABSTRACT
Dehydrogenation catalysts fall into two general categories: simple dehydrogenation catalysts, which act primarily by a high-temperature thermal effect, and oxidative dehydrogenation catalysts, which are the more sophisticated and complicated of the two. Chrome alumina catalyst is one of those for which reuse is the most feasible of the possible recovery procedures for the deactivated material because of the chromium oxide content and the toxicity of the water-soluble Cr6+ component. The water soluble Cr6+ may be formed as a result of weathering and oxidation of any Cr3+ present in a discarded catalyst. Spent calcium nickel phosphate catalyst has nickel values, and calcium phosphate is an ingredient in most fertilizers. The nickel can be processed by a smelter, and if the first recovery step is an acid extraction of the nickel that leaves a nontoxic calcium phosphate, the phosphate can be used beneficially by a fertilizer manufacturer for superphosphate.
