Foam catalysts, method of manufacture and method of using
AssigneeImperial Chemical Industries PLC
InventorsMartyn V. Twigg, William M. Sengelow
Life of this patent
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Abstract
A catalyst, or a precursor thereto, comprises, as the active material or as a support therefor, a ceramic foam having a network of irregular passages extending therethrough, said passages having an average minimum dimension in the range 20 to 300 .mu.m, said foam having a total porosity in the range 40 to 85% and an apparent density of at least 0.7 g.cm.sup.-3. The foam may be made by forming a negative replica of an open cell plastics foam by impregnation of the latter with a dispersion of the ceramic material, followed by drying and calcining the impregnated foam to remove the plastics material and to cause the ceramic material to sinter. For a steam reforming catalyst the ceramic may be alpha alumina and the active material nickel and/or cobalt.
Claims16
A catalyst containing a catalytically active material, or a precursor to such a catalyst containing a material convertible to catalytically active material, wherein said catalytically active material, or said material convertible thereto, comprises, or is supported on, a ceramic foam having a network of irregular passages extending therethrough, said passages having an average minimum dimension in the range of 20 to 300 .mu.m, said foam having a total porosity in the range 40 to 85% and an apparent density of at least 1 g.cm.sup.-3.
A process for the production of a catalyst containing a catalytically active material, or a precursor to such a catalyst containing a material convertible to catalytically active material, wherein said catalytically active material, or said material convertible thereto, comprises, or is supported on, a ceramic foam, said process comprising forming said ceramic foam by forming a negative replica of an open cell organic plastics foam by impregnating said foam with a thixotropic dispersion of a particulate ceramic material in a carrier liquid so that the pores of the foam are filled with said dispersion, drying said impregnated foam without removing ceramic material from the pores thereof, heating said foam in air to remove the organic plastics foam and to cause the ceramic particles to sinter.
A catalyst containing a catalytically active material, or a precursor to such a catalyst containing a material convertible to catalytically active material, wherein said catalytically active material, or said material convertible thereto, comprises a ceramic foam containing a major amount, by weight, of oxides of one or more metals selected from iron, cobalt, nickel, copper, vanadium, molybdenum, tungsten, chromium, manganese, and zinc, said ceramic foam having a network of irregular passages extending therethrough, said passages having an average minimum dimension in the range 20 to 300 .mu.m, said foam having a total porosity in the range 40 to 85% and an apparent density of at least 0.7 g.cm.sup.-3.
A catalyst containing a catalytically active material, or a precursor to such a catalyst containing a material convertible to catalytically active material, wherein said catalytically active material, or said material convertible thereto, comprises, or is supported on, a ceramic foam having a network of irregular passages extending therethrough, said passages having an average minimum dimension in the range 20 to 300 .mu.m, said foam having a total porosity in the range 40 to 85% and an apparent density of at least 0.7 g.cm.sup.-3, and the megaporosity constitutes 60-90% of the total porosity.
A catalyst containing a catalytically active material, or a precursor to such a catalyst containing a material convertible to catalytically active material, wherein said catalytically active material, or said material convertible thereto, is supported on a ceramic foam having a network of irregular passages extending therethrough, said passages having an average minimum dimension in the range 20 to 300 .mu.m, said foam having a total porosity in the range 40 to 85% and an apparent density of at least 0.7 g.cm.sup.-3.
Dependencies are inferred from the claim text.