Hydrocarbon-decomposing catalyst, process for decomposing hydrocarbons and process for producing hydrogen using the catalyst, and power generation system
The present invention relates to a catalyst for decomposing hydrocarbons including hydrocarbons having 2 or more carbon atoms, comprising magnesium, aluminum, nickel and cobalt as constitutional elements, and further comprising ruthenium and/or palladium, wherein the metallic ruthenium and/or metallic palladium in the form of fine particles have an average particle diameter of 0.5 to 20 nm, and a content of the metallic ruthenium and/or metallic palladium is 0.05 to 5.0% by weight based on the weight of the catalyst. The catalyst of the present invention is capable of efficiently decomposing hydrocarbons including hydrocarbons having 2 or more carbon atoms (C 2 or more hydrocarbons), is less expensive, and exhibits an excellent catalytic activity for decomposition and removal of hydrocarbons, in particular, an excellent capability of decomposing propane, and an excellent anti-coking property.
1. A catalyst for decomposing hydrocarbons including hydrocarbons having 2 or more carbon atoms, comprising magnesium oxide, aluminum oxide, metallic nickel and metallic cobalt as constitutional elements, and further comprising metallic ruthenium and/or metallic palladium and a clay mineral, wherein
the metallic ruthenium and/or metallic palladium in the form of fine particles having an average particle diameter of 0.5 to 20 nm,
a content of the metallic ruthenium and/or metallic palladium being 0.05 to 5.0% by weight based on the weight of the catalyst, and
the clay mineral is present in an amount of 1 to 50% by weight based on the weight of the catalyst.
2. A catalyst for decomposing hydrocarbons including hydrocarbons having 2 or more carbon atoms according to claim 1 , wherein the metallic nickel in the form of fine particles have an average particle diameter of 1 to 20 nm, and a content of the metallic nickel is 0.1 to 20% by weight based on the weight of the hydrocarbon-decomposing catalyst.
3. A catalyst for decomposing hydrocarbons including hydrocarbons having 2 or more carbon atoms according to claim 1 , wherein the metallic cobalt in the form of fine particles have an average particle diameter of 1 to 20 nm, and a content of the metallic cobalt is 0.01 to 20% by weight based on the weight of the hydrocarbon-decomposing catalyst.
4. A catalyst for decomposing hydrocarbons including hydrocarbons having 2 or more carbon atoms according to claim 1 , wherein at least one element selected from the group consisting of ruthenium, rhodium, iridium, platinum, gold, silver, palladium, nickel, cobalt, copper, iron, zinc, vanadium and manganese, which has an average particle diameter of not more than 50 nm, is supported on the clay mineral.
5. A process for producing a mixed reformed gas comprising hydrogen from hydrocarbons, comprising a step of reacting the hydrocarbons including hydrocarbons having 2 or more carbon atoms with steam at a temperature of 250 to 850° C., at a molar ratio of steam to carbon (S/C) of 1.0 to 6.0 and at a space velocity (GHSV) of 100 to 100000 h −1 in the presence of the hydrocarbon-decomposing catalyst as defined in claim 1 .