Spinel based high temperature shift catalysts
AssigneeJohnson Matthey PLC
InventorsAndrew Mark Ward, Sean Alexander Axon, Paul John Murray
Life of this patent
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Abstract
A method is described for producing a high temperature shift catalyst, not requiring a reduction step prior to use, by precipitating a composition containing divalent and trivalent iron compounds and a modifier metal selected from trivalent chromium and/or manganese compounds from an aqueous solution containing iron and modifier metal salts with a base, and forming the resultant precipitate into shaped catalyst units, without exposing said precipitate to an oxidizing atmosphere at temperatures above 200° C.
Claims16
A method for producing shaped catalyst units, in the form of pellets, granules, tablets or extrudates, suitable for the high temperature shift reaction comprising precipitating an oxidic magnetite material containing divalent and trivalent iron and trivalent chromium from an aqueous solution containing iron and chromium salts with a base and forming the resultant precipitate into a pellet, granule, tablet or extrudate without exposing said precipitate to an oxidising atmosphere at temperatures above 200° C. wherein the aqueous solution comprises divalent iron salts and trivalent chromium salts, the divalent iron being partially oxidised by the use of an oxidising agent that converts a portion of the divalent iron into trivalent iron.
A method according to 1 wherein precipitation is effected at temperatures between 60 and 100° C. and a pH between 3.5 and 5.
A shift process comprising passing a mixture of carbon monoxide and steam over a bed of shaped catalyst units, without having subjected the shaped catalyst units to a prior reduction step, said shaped catalyst units having been prepared by precipitating an oxidic magnetite material containing divalent and trivalent iron and trivalent chromium from an aqueous solution containing iron and chromium salts with a base and forming the resultant precipitate into a pellet, granule, tablet or extrudate without exposing said precipitate to an oxidising atmosphere at temperatures above 200° C. wherein the aqueous solution comprises divalent iron salts and trivalent chromium salts, the divalent iron being partially oxidised by the use of an oxidising agent that converts a portion of the divalent iron into trivalent iron.
Dependencies are inferred from the claim text.