NOVELTY - An integrated combustor comprises combustion chamber, endothermic reaction chamber, and thermally conductive wall. The combustion and reaction chambers comprise combustion catalyst (124) and catalyst, respectively. The reaction chamber has length. The conductive wall is disposed between the combustion chamber and reaction chamber. The combustion catalyst is on a side of the reaction chamber.    USE - For combusting or steam reforming. It is also used in reforming hydrocarbons to produce hydrogen for fuel cell.    ADVANTAGE - The invention has very small size, steady performance, and can be operated at low temperature with low carbon monoxide output while maintaining high efficiency levels.    DETAILED DESCRIPTION - An integrated combustor comprises combustion chamber, endothermic reaction chamber, and thermally conductive wall. The combustion and reaction chambers comprise combustion catalyst and catalyst, respectively. The reaction chamber has length. The conductive wall is disposed between the combustion chamber and reaction chamber. The combustion catalyst is on a side of the reaction chamber so that during operation, heat from combustion reaction on the combustion catalyst is transferred along the length of reforming chamber. The total heat flux (less than 10 %) into the endothermic reaction chamber is perpendicular to length.    INDEPENDENT CLAIMS are included for:    (1) transferring heat to endothermic reaction in integrated combustor comprising combusting fuel on the combustion catalyst and generating heat in combustion chamber; and    (2) reforming alcohol in device with combustion and steam reforming chambers comprising combusting fuel in combustion chamber, transferring heat from the combustion chamber across a chamber wall into steam reforming chamber, and reforming an alcohol at not greater than 300 degrees C to produce product stream comprising hydrogen gas in hydrogen gas: carbon monoxide ratio of at most 70:1. The method has thermal efficiency of at least 10 %.    DESCRIPTION OF DRAWING(S) - The figure shows a cross sectional view of the micro reformer.    Fuel supply layer (102)    Combustion layer (104)    Steam reforming layer (106)    Separation plates (108, 110)    Fuel supply channel (112)    Groove (114)    Cavity (118)    Exhaust channel (120)    Opening (122)    Combustion catalyst (124)    Reforming channel (128)