(JP7232902-A)      A Shell and tube reactor (A) producing hydrogen and carbon monoxide from the mixture of natural gas and steam, in which gas permeable ceramic (B) is filled and it encloses the ends of multiple tubes (C). Ends of (C) (one third of B-s length are buried in (B), which also fills up inside of (A) at the inlet of combustion gas, (B)'s downstream surface is covered with laminated wire meshes. (B) has continuous pores and (B) is moulded to suit the shape of (C). (B) is made of mullite, alumina, zirconia, or silicon carbide. (C) is catalytic double tube.    USE -   Used for transforming gas for fuel cells.    ADVANTAGE -   Able to raise thermal efficiency and to prevent inhomogeneous heating of catalytic tubes.    (EP661768-B1)      A method of the production of a reformed gas composed mainly of hydrogen and carbon monoxide to be used for a fuel cell by using a multi-tubular reformer provided with a plurality of bayonet type double-wall catalyst tubes in a pressure vessel or shell and feeding a hydrocarbon gas such as natural gas and steam to the reformer, in which porous media (13) composed of ceramic foams having open cells at a ratio in the approximate range of from 4-40 cells per 25 mm. are arranged in such a manner in the shell side flue gas inlet part as to envelope the leading end parts of the catalyst tubes (3,4).    (US5876469-A)       Reformed gas (7) contg. H2plus CO is obtd. by supplying a hydrocarbon gas and steam (2) to a multi-tubular reformer (1) provided with a number of bayonet type double wall catalyst tubes (3 and 4) in a pressure vessel. Porous media comprising ceramic foam (13 and 14) are arranged in a shell side flue gas inlet part (9) to envelope the leading end parts of the tubes. The reformer is also claimed.    USE -   Reformed gas prod. is used in fuel cells which generate electric power.    ADVANTAGE -   Heat transfer from flue gas to the catalyst tubes is enhanced since the porous media accumulate heat and radiate this heat in the direction of the outer tube walls. Uneven heating is avoided because of repression of wall effects and flue gas channelling. Reformer operation is stabilised.