title: Multifunctional Pd/Ni-Co catalyst for hydrogen production by chemical looping coupled with steam reforming of acetic acid.
abstract: High yield of high-purity H2 from acetic acid, a model compound of bio-oil obtained from the fast pyrolysis of biomass, was produced by sorption-enhanced steam reforming (SESR). An oxygen carrier was introduced into a chemical loop (CL) coupled to the cyclical SESR process to supply heat in situ for the endothermic sorbent regeneration to increase the energy efficiency of the process. A new multifunctional 1 %Pd/20 %Ni-20 %Co catalyst was developed for use both as oxygen carrier in the CL and as reforming catalyst in the SESR whereas a CaO-based material was used as CO2 sorbent. In the sorbent-air regeneration step, the Ni-Co atoms in the catalyst undergo strong exothermic oxidation reactions that provide heat for the CaO decarbonation. The addition of Pd to the Ni-Co catalyst makes the catalyst active throughout the whole SESR-CL cycle. Pd significantly promotes the reduction of Ni-Co oxides to metallic Ni-Co during the reforming stage, which avoids the need for a reduction step after regeneration. H2 yield above 90 % and H2 purity above 99.2 vol % were obtained.
authors.affiliation: Thermochemical Processes Unit, IMDEA Energy Institute, Avenida Ramón de la Sagra 3, 28935 Móstoles (Spain).
authors.forename: Javier
authors.initials: J
authors.lastname: Fermoso
authors.forename: María V
authors.initials: MV
authors.lastname: Gil
authors.forename: Fernando
authors.initials: F
authors.lastname: Rubiera
authors.forename: De
authors.initials: D
authors.lastname: Chen
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry; D002245:Carbon Dioxide / Q000737:chemistry; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D006859:Hydrogen / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D010087:Oxides / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D013227:Steam
chemical_list: D017610:Calcium Compounds; D010087:Oxides; D013227:Steam; D002245:Carbon Dioxide; D003035:Cobalt; D010165:Palladium; D009532:Nickel; D006859:Hydrogen; C016538:lime; D019342:Acetic Acid
keywords: biomass; hydrogen; hydrotalcite; oxygen carrier; steam reforming