A possible process for membrane enhanced steam reforming of methane in a downflow-fluidized bed is tested in a novel Riser Simulator. Experiments with a palladium membrane and a nickel catalyst indicate that the rate of methane reforming is first order with respect to the methane partial pressure. The rate constant was found to be 1.632x10(-7) +/-10% mol/g(cat)s with an activation energy of 53,640 J/mol +/-60%. Inclusion of a high temperature hydrogen permeable membrane moderately increases the observed conversion of methane while at the same time producing synthesis gas suitable for direct conversion to methanol.