Numerical analysis on autothermal steam methane reforming: Effects of catalysts arrangement and metal foam insertion

Abstract

This paper presents a numerical study of hydrogen production from methane. An autothermal reforming (ATR) process which belongs to the wall coated reactors family is adopted. A methane combustion (MC) over Pt/Al2O3 catalyst provides the required heat to steam methane reforming (SMR) over Ni/Al2O3 catalyst. Aiming to attain smooth and low temperature profiles with an improvement of the reactor performances, three configurations were designed to be analyzed and compared with the same amounts of the used catalysts. In the first configuration, the MC and SMR catalysts are coated successively (similar to conventional dual-bed ATR design). In the second configuration the catalysts are parallelly deposed. Finally, in the third configuration a copper foam (CF) is inserted in the reactor to promote the heat conduction. The obtained results show that the simultaneous depletion of methane in the parallel combustor and reformer catalysts causes a smooth temperature profile. In the first arrangement, the temperature can reach a high value of 1300 °C, which can be reduced by 42.63% when using the second configuration and by 45.38% with the use of the CF. However, the hydrogen yield is not affected significantly. In fact, it is improved from 32.19% to 32.96% and 33.48% when using the first, second and third configuration respectively. Furthermore, when using the CF, the catalysts length can be reduced by 10.71% with almost the same results than that of the second configuration.