Reaction and hydrogen production phenomena of ethanol steam reforming in a catalytic membrane reactor

Ethanol steam reforming (ESR) can be performed efficiently using catalytic membrane reactors (CMR) to enhance H2 production. To investigate the reaction of ESR and the effect of membrane on H2 production, a numerical model was developed to predict the chemical reaction phenomena. The simulations suggested that lower Reynolds numbers were conducive to ethanol conversion and H2 recovery. The H2 yield could be increased by recovering H2 from the ESR product gas using the Pd membrane, and the membrane had a better performance at low Reynolds numbers. Alternatively, total H2 production increased at higher Reynolds numbers, but H2 recovery decreased due to shorter residence time in the reactor. Increasing the S/E ratio enhanced the ESR performance to produce H2 due to the excessive steam supplied to the reaction, but the H2 recovery declined slightly and more energy would be required. Although a high inlet temperature increased the H2 concentration on the retentate side, it also caused the membrane to experience a higher risk of melting. An increase in pressure facilitated both the ethanol conversion and H2 recovery, scribing to more H2 permeating through the membrane. Overall, the obtained results in this study are beneficial to ESR operation for H2 production.