Sorption-enhanced steam reforming of methane in a fluidized bed reactor with dolomite as CO2-acceptor

An experimental investigation was conducted in which carbon dioxide was captured in order to shift the steam reforming equilibrium for the production of hydrogen. An atmospheric-pressure bubbling fluidized bed reactor (BFBR) of diameter 100mm was operated cyclically and batchwise, alternating between reforming/carbonation conditions and higher-temperature calcination conditions to regenerate the sorbent. Equilibrium H-2-concentration of > 98% on a dry basis was reached at 600 degrees C and 1.013 x 10(5) Pa, with dolomite as the CO2-acceptor. The hydrogen concentration remained at 98-99 vol% (dry basis) after four reforming/calcination cycles. The total production time decreased with an increasing number of cycles due to loss of CO2-uptake capacity of the dolomite, but the reaction rate seemed unaffected. Variation of the superficial gas velocity within the bubbling bed regime showed that the overall reaction rate was sufficiently fast to reach equilibrium, making bubbling bed reactors attractive for this process. (c) 2005 Elsevier Ltd. All rights reserved.