A mixture of ethanol and acetic acid (0.25:0.75 M ratio) was used as feedstock for hydrogen production in a bench scale sorption enhanced steam reforming (SESR) process. Simulation studies of steam reforming plants (with and without CO₂ capture) were conducted using Aspen Plus software to explore whole plant efficiency. Bifunctional nickel catalysts supported on CaO and alumina (NiCaAl), as well as a similar one doped with ceria (NiCaAlCe), were prepared via citrate method. Several characterisation techniques were employed. In the reduced catalysts, the presence of CaO, Ca(OH)₂, and Ni⁰ peaks was observed, with an additional CeO₂ peak for the NiCaAlCe catalyst. In the thermogravimetric analysis, the NiCaAlCe experienced a smaller decrease in CO₂ capture capacity (24 %) compared to the ceria-free catalyst (31 %) over 20 carbonation-calcination cycles. During SESR, the conversions of ethanol and acetic acid were greater than 99 % and 92 %, respectively. The reaction was carried out at 500 °C and 1 atm for 119 min, using 0.80 g of bifunctional catalyst. The feed was evaporated at 0.033 mL/min, and steam was co-fed at twice the stoichiometric requirement. The hydrogen molar fraction in the dry gas was exceeded 90 % during SESR Regarding the hydrogen molar fraction and the duration of the pre-breakthrough time, no significant contribution was observed to justify the use of ceria. The plant simulations showed that SESR achieved a hydrogen yield of 0.70 mol H₂/mol bio-oil, surpassing CSR's 0.43 mol H₂/mol bio-oil. Moreover, SESR presented a thermal efficiency of 0.32, lower than the efficiency of 0.49 of the CSR. Lastly, SESR exhibited lower CO₂ emissions, both in the reformer (10.34 kgCO₂/kgH₂ produced) and at plant's scale, including the biomass burner (25.12 kgCO₂/kgH₂ produced), compared to CSR's 27.14 kgCO₂/kgH₂ and 25.73 kgCO₂/kgH₂, respectively.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)