(EP815605-A1)      Hydrocarbon fuel gas selective oxidiser assembly comprises: (i) a first inlet line which directs a mixture of fuel gas and oxygen into a gas flow section comprising first and second plates which define a number of gas passages between them; (ii) a second inlet line to direct coolant into the coolant section which is adjacent to the gas flow section and is formed from the first plate and, spaced therefrom on the side opposite the second plate, a third plate such as to include a number of coolant passages between them, whereby heat is transferred from the gas to the coolant via the first plate; and (iii) first and second outlets for the oxidised gas and the coolant respectively. Also claimed is the above assembly applied to the selective oxidation of a hydrocarbon fuel gas, and wherein the gas mixture and the coolant flow in opposite directions. Also claimed is the above assembly for a hydrocarbon gas, where the gas and coolant inlets are disposed on adjacent sides such that the flows are in cross directions. Also claimed is a method of converting carbon monoxide in reformed fuel gas to carbon dioxide by passing a mixture of the gas and oxygen over an oxidising platinum catalyst and providing an adjacent coolant stream flowing in the opposite direction.    USE -   The fuel gas is used in a fuel cell power plant.    ADVANTAGE -   The flat plate construction enables the heat exchange per unit volume of catalyst in intimate contact with the heat exchange surface to be increased such that for a 20 kW plant, the volume of the selective oxidiser can be reduced from 4 ft3 to 0.1 ft3.    (US5853674-A)      Hydrocarbon fuel gas selective oxidiser assembly comprises: (i) a first inlet line which directs a mixture of fuel gas and oxygen into a gas flow section comprising first and second plates which define a number of gas passages between them; (ii) a second inlet line to direct coolant into the coolant section which is adjacent to the gas flow section and is formed from the first plate and, spaced therefrom on the side opposite the second plate, a third plate such as to include a number of coolant passages between them, whereby heat is transferred from the gas to the coolant via the first plate; and (iii) first and second outlets for the oxidised gas and the coolant respectively. Also claimed is the above assembly applied to the selective oxidation of a hydrocarbon fuel gas, and wherein the gas mixture and the coolant flow in opposite directions. Also claimed is the above assembly for a hydrocarbon gas, where the gas and coolant inlets are disposed on adjacent sides such that the flows are in cross directions. Also claimed is a method of converting carbon monoxide in reformed fuel gas to carbon dioxide by passing a mixture of the gas and oxygen over an oxidising platinum catalyst and providing an adjacent coolant stream flowing in the opposite direction.    USE -   The fuel gas is used in a fuel cell power plant.    ADVANTAGE -   The flat plate construction enables the heat exchange per unit volume of catalyst in intimate contact with the heat exchange surface to be increased such that for a 20 kW plant, the volume of the selective oxidiser can be reduced from 4 ft3 to 0.1 ft3.    (JP11502366-W)      Hydrocarbon fuel gas selective oxidiser assembly comprises: (i) a first inlet line which directs a mixture of fuel gas and oxygen into a gas flow section comprising first and second plates which define a number of gas passages between them; (ii) a second inlet line to direct coolant into the coolant section which is adjacent to the gas flow section and is formed from the first plate and, spaced therefrom on the side opposite the second plate, a third plate such as to include a number of coolant passages between them, whereby heat is transferred from the gas to the coolant via the first plate; and (iii) first and second outlets for the oxidised gas and the coolant respectively. Also claimed is the above assembly applied to the selective oxidation of a hydrocarbon fuel gas, and wherein the gas mixture and the coolant flow in opposite directions. Also claimed is the above assembly for a hydrocarbon gas, where the gas and coolant inlets are disposed on adjacent sides such that the flows are in cross directions. Also claimed is a method of converting carbon monoxide in reformed fuel gas to carbon dioxide by passing a mixture of the gas and oxygen over an oxidising platinum catalyst and providing an adjacent coolant stream flowing in the opposite direction.    USE -   The fuel gas is used in a fuel cell power plant.    ADVANTAGE -   The flat plate construction enables the heat exchange per unit volume of catalyst in intimate contact with the heat exchange surface to be increased such that for a 20 kW plant, the volume of the selective oxidiser can be reduced from 4 ft3 to 0.1 ft3.