The compact fuel processor that uses methanol as a feedstock for the production of hydrogen and for temperature control was studied by computational fluid dynamics. The processor integrates in a single package the methanol-water evaporator, the gas flow distributors, the steam reformer and the methanol-air catalytic combustor. The reformer and the combustor were formed as tubular reactors that possessed a single metallic body like a monolith with an array of circular cross-section through-holes. Part of holes was filled with reforming catalyst and the other part was filled with a catalyst for the oxidation of methanol. The design provides efficient heat transfer between the reformer and the combustor and efficient temperature control of the reformer. The temperature distribution in the metallic body of the reformer and the combustor is almost uniform. The value of temperature nonuniformity does not exceed the value Delta T = 2.4% in any cross-section of the reaction zone. Maximum overall effectiveness of the fuel processor is achieved at the value of methanol feed equal 17.24 mmol/min (GHSV = 12,424h(-1)) and 8.75 mmol/min (GHSV = 16,632 h(-1)) in the reformer and in the combustor, respectively. Under these conditions the hydrogen performance is equal to 70.0 1/h (48.7 mmol/min) and the temperature is equal to 286.4 degrees C in the reformer. C) 2015 Elsevier ay. All rights reserved.