Sorption-enhanced glycerol steam reforming over lithium cuprate-based bifunctional material for the production of high-purity hydrogen

Abstract

We investigated the production of high-purity H2 through sorption-enhanced glycerol steam reforming (SEGSR) using lab-made bifunctional materials consisting of nickel, Al2O3, and Li2CuO2. Different bifunctional materials were prepared with 10 wt % Ni loading but varying wt % of Al2O3 and Li2CuO2, and their catalytic activity was evaluated in a continuous fixed-bed down-flow reactor. HM-50, which had an equal wt % of Al2O3 and Li2CuO2, showed the highest performance. The conversion of glycerol and the purity of H2 were examined with respect to temperature, feed flow rate, and steam-to-carbon molar ratio (S/C). At the optimum reaction conditions (temperature = 700 °C, feed flow rate = 0.5 ml/min, and S/C = 6), glycerol conversion and H2 purity were 100 % and 94 mol %, respectively. The adsorption capacity of HM-50 was found to be 3.9 mmol CO2 per gram. With a breakthrough time of 15 min, the substance was stable for 13 adsorption-desorption cycles. The material was regenerated by substituting the feed with a N2 and steam mixture heated to 700 °C for 30 min. A most likely reaction mechanism suggested that glycerol was catalytically converted to acetaldehyde, which was then quickly decomposed to CO and CH4. We are the first research team to investigate the use of Li2CuO2 in any steam reforming process.