Shell impregnated catalyst and process for producing a shell impregnated catalyst body

Abstract

The present application relates to a process for producing a catalyst,said process comprising the steps of: providing a carrier and following modifying said carrier by a first impregnation with at least one alkaline earth metal in a first metal precursor solution. The first metal precursor is decomposed to form at least one metal oxide or metal hydroxide thereby obtaining a modified carrier and a second impregnation is carried out by incipient wetness by a second precursor solution comprising at least one metal Me in a second solution. Finally the second precursor is decomposed thereby obtaining a catalyst body having an enrichment of the at least one metal Me in the outer shell of the catalyst body, said at least one metal being present in a concentration having either as an egg-shell profile or a hammock profile.

Description

[0001]The invention relates to a catalyst and a process for producing a catalyst for syngas generation.[0002]New catalysts are under constant development as the requirements for efficiency, lifetime and also costs of the catalyst are ever increasing.[0003]For various reasons it may be beneficial to reduce the amount of metals in the catalyst, for example it may be relevant to minimize the amount of the metal in the catalyst due to environmental considerations. In catalysts for reactions limited by mass transfer such as steam reforming reactions or catalytic partial oxidation at high temperatures the reactive metal is only needed in the surface zone of a catalyst body, i.e. in such catalyst bodies it may be relevant to have a significant metal concentration in the surface zone only. This surface concentrated metal layer also limits unwanted side reactions such as ammonia production in steam reforming of nitrogen rich feedstocks.[0004]On the other hand, however, the requirements to th...

AI Technical Summary

Benefits of technology

The new method described in the patent allows for the improvement of the structural stability and lifetime of catalysts used for steam reforming without affecting their strength or integrity. By impregnating the carrier with an alkaline-earth metal, the carriers reactivity and basicity are increased without changing their structure. This change in affinity for reaction with a particular metal can be controlled, leading to the distribution of metal in the catalyst body being controlled.

Problems solved by technology

New catalysts are under constant development as the requirements for efficiency, lifetime and also costs of the catalyst are ever increasing.

On the other hand, however, the requirements to the structural stability and lifetime of the catalyst are high as it is critical for loading and running the reactors with the catalyst.

Due to these requirements to strength of the carrier, the carrier for e.g. steam reforming catalysts is most often sintered at high temperatures, which reduces the reactivity of the carrier rendering e.g. shell impregnation difficult by known means.

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