Abstract:
Methane in a feedstock gas having methane as its main component, is partially oxidized with oxygen, which selectively permeates from a first side to a second side of a oxygen selective permeation ceramic membrane. Air is contacted with the first side of the oxygen selective permeation ceramic membrane, and the feedstock gas containing methane is contacted with the second side of the oxygen selective permeation ceramic membrane. A first catalyst for partial oxidation of methane is disposed two-dimensionally on the second side of the oxygen selective permeation ceramic membrane, and a second catalyst for partial oxidation of methane is disposed three-dimensionally in the feedstock gas stream downstream from the first catalyst. Furthermore, steam is mixed into the feedstock gas stream at a ratio of 0.25 to 0.5 moles of steam based on the moles of carbon in the feedstock gas.
Abstract:
A porous catalyst layer containing mixed conducting oxide having substantially a perovskite structure and containing a first element selected from Co and Fe, and a second element selected from In, Sn and Y arranged in the B site in the perovskite structure is contiguous to a second surface (1a) of a selective oxygen-permeable dense continuous layer (1) containing mixed conducting oxide. A porous intermediate catalyst layer (3) containing mixed conducting oxide and at least one of Co, Fe, Mn and Pd is contiguous to a first layer (1b) of the dense continuous layer (1). A porous reactive catalyst layer (4) provided with a metal catalyst selected from at least one of Ni, Co, Ru, Rh, Pt, Pd, Ir and Re and a support is continguous to the porous intermediate catalyst layer (3) in a manner to sandwich between the dense continuous layer (1) and the porous reactive catalyst layer (4).