Process using fluidized bed catalyst
AssigneeThe International Nickel Company, Inc.
InventorsJohn K. Pargeter, Umar M. U. Ahmad
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Abstract
An unsupported particulate catalyst especially useful for methanation reactions is prepared by a method comprising fluid-bed roasting agglomerates of nickel sulfide to form a particulate precursor material which can be reduced to composite particles consisting essentially of a nickel-oxide core with a then coherent adherent layer of nickel thereon, the reduced particles being characterized at the surface by the presence of microcapillary pores interconnecting with each other and the outer surface of the particles.
Claims32
In a catalytic process for converting carbon monoxide and hydrogen contained in a feed gas stream to methane, wherein said feed gas is contacted with a nickel-containing catalyst in a fluidized bed;
- the improvement comprising contacting said stream with an unsupported particulate catalyst composed of up to about 13% oxygen, less than about 1% sulfur and the balance greater than about 75% nickel, said particulate catalyst having a minimum of fines, said catalyst particles being a composite material consisting essentially of a nickel oxide core and a thin adherent, coherent layer of nickel on said core, the nickel oxide core having been formed as unsupported nickel oxide particles having a particle size of about 0.25 to about 1.2 mm. by a method comprising fluid-bed roasting agglomerates comprised of nickel sulfide in an oxidizing atmosphere, and the nickel layer having been developed under reducing conditions from the nickel oxide particles, said nickel layer being characterized by the presence of microcapillary pores interconnecting with each other and with the outer surface of the particles, said reduced catalyst being non-pyrophoric in the reduced state both before and after use, whereby the feed gas stream can be reacted in the fluidized bed with high throughput in the presence of an active, selective catalyst which is resistant to attrition in said fluidized bed, and whereby said reaction can be carried out without the use of stabilizing equipment for the catalyst.
In a methanation process for converting carbon monoxide and hydrogen contained in a feed stream to methane, wherein said feed gas is contacted with a nickel-containing catalyst in a fluidized bed, the improvement comprising contacting said stream with a catalyst developed from an unsupported particulate precursor catalyst material, said precursor catalyst comprising nickel oxide and containing at least about 7% oxygen, less than about 1% sulfur, and the balance predominantly nickel and having a bulk density of less than about 4 g/cc, a particle size of about 0.25 to about 1.2 mm with a minimum of fines, said precursor catalyst material having been formed by fluid-bed roasting nickel sulfide in an oxidizing atmosphere and said precursor catalyst material on being subjected to reducing conditions being converted to a reduced catalyst material having at least a portion of the nickel oxide at least at the surface being reduced to a thin layer of nickel, said nickel being characterized by the presence of microcapillary pores interconnecting with each other and with the outer surface of the particles, and said reduced catalyst material having a nickel content of greater than about 75%, a superficial surface area of at least 0.4 m.sup.2 /g and a pore volume of at least about 0.001 ml/g, and said reduced catalyst being non-pyrophoric in the reduced state before and after use.
In a catalytic methanation process comprising reacting carbon monoxide and hydrogen in a fluidized bed reaction zone containing a nickel-containing catalyst material, the improvement comprising contacting said reactants in said fluidized bed with an unsupported catalyst containing greater than about 75% nickel and prepared by a method comprising fluid-bed roasting agglomerates comprised of nickel sulfide in an oxidizing atmosphere at a temperature of at least about 600.degree. C. up to about 1500.degree. C. to form a particulate precursor catalyst material comprising nickel oxide, said nickel oxide containing at least about 7% oxygen, and subjecting said precursor catalyst material to reducing conditions to convert at least a part of the nickel oxide at the surface of the particles to elemental nickel, said reduced catalyst being non-pyrophoric in the reduced state both before and after use, whereby said process can be carried out without the use of stabilizing equipment for the catalyst.
Dependencies are inferred from the claim text.