Patent ID: 7182921
Filing Date: 2007-02-27
Classification: B01J,C01B,Y02P

Abstract:
1. A cylindrical steam reforming unit comprising: (a) a first cylindrical body, a second cylindrical body and a third cylindrical body disposed concentrically in spaced-apart relationship and successively increasing in diameter, said first and third cylindrical bodies both having a bottom plate; (b) a radiation cylinder disposed inside of said first cylindrical body in spaced-apart relationship therewith and having a central axis concentric with said first cylindrical body; (c) a burner disposed at a radial central portion of said radiation cylinder; (d) a reforming catalyst layer provided in a first space between the first cylindrical body and the second cylindrical body and a preheating layer disposed in the first space between the first cylindrical body and the second cylindrical body upstream of the reforming catalyst layer for preheating a starting gas; (e) a heat recovery layer provided in a second space between the second cylindrical body and the third cylindrical body, said second space being in communication with the first space and the heat recovery layer being situated with respect to the reforming catalyst layer such that heat contained in a reformed gas can be transferred to the reforming catalyst layer; (f) a CO shift catalyst layer provided between the second cylindrical body and the first cylindrical body downstream of the heat recovery layer; and (g) a CO removal catalyst layer provided downstream of the CO shift catalyst layer and in communication therewith, wherein a combustion exhaust gas generated in said burner within the radiation cylinder reverses its direction of flow between an end portion of the radiation cylinder and the bottom plate of the first cylindrical body and flows into a third space provided between the radiation cylinder and the first cylindrical body in a direction opposite to the flow of the starting gas through the reforming catalyst layer; the preheating layer is positioned at an outer periphery of the radiation cylinder and the CO shift catalyst layer is positioned at an outer periphery of the preheating layer; a reformed gas generated in the reforming catalyst layer reverses its direction of flow between an end portion of the second cylindrical body and the bottom plate of the third cylindrical body, flows into the heat recovery layer, collects heat from the reforming catalyst layer and subsequently flows into the CO shift catalyst layer; and the reformed gas passes through the CO removal catalyst layer after passing through the CO shift catalyst layer.