A pilot-scale fluidized-bed membrane reactor was tested for the production of hydrogen. The prototype reactor operated under steam methane reforming (SMR) and autothermal reforming (ATR) conditions, without membranes and with membranes of different total areas. Heat was added either externally or via direct air addition. Hydrogen permeate purity of up to 99.995+% as well as a pure-H-2-to-natural-gas yield of 2.07 were achieved with only half of the full complement of membrane panels active under SMR conditions. A permeate-H-2-to reactor natural gas feed molar ratio > 3 was achieved when all of the membrane panels were installed under SMR conditions. Experimental tests investigated the influence of such parameters as reactor pressure, hydrogen permeate pressure (vacuum vs atmospheric pressure), air top/bottom split, feed flowrate and membrane area. Reactor performance was strongly dependent on the active membrane surface area. (C) 2008 Elsevier Ltd. All rights reserved.