Sorption-enhanced ethanol steam reforming on Ce-Ni/MCM-41 with simultaneous CO2 adsorption over Na- and Zr- promoted CaO based sorbent

Abstract

In this study, sorption-enhanced ethanol steam reforming (SEESR) is investigated using a Ce-Ni/MCM-41 as a catalyst in the presence of Na or/and Zr promoted CaO-based adsorbents. Ce-Ni/MCM-41 and promoted sorbents were synthesized by wet impregnation method. The catalyst was characterized by XRD, FTIR, TGA, EFSEM, TEM, H2-TPR and N2 adsorption/desorption and promoted sorbents were studied by XRD, EFSEM, BET, TEM and TGA analysis. Sorption experiments were performed to verify sorbent activity for CO2 removing. The results indicated that with doping different promoter on CaO sorbent and also with increasing Na loading, there was an increase in BET surface area, the reduction in particle size and thereupon an enhancement in CO2 sorption capacity. Higher BET surface area, smaller particle size, and superior CO2 sorption capacity were obtained on Na-Zr-CaO sorbent. Sorption-enhanced steam reforming process of ethanol on synthesized catalyst and sorbents were performed at 600 °C and water to ethanol molar ratio of 6. The effect of sorbent to catalyst ratio and the arrangement of sorbent and catalyst (like two separated layers and the mixture of sorbent and catalyst in a single layer) were also studied. The best results were demonstrated on Na-Zr-CaO sorbent and with the separated array. Hydrogen production via a SEESR process with Na-Zr-CaO as sorbent was ∼94% that is 24% more than that of conventional ethanol steam reforming (ESR) reaction.