Реферат: Producing syngas and hydrogen from biofuels using catalytic membrane reactors for reagent (oxygen) and/or products (hydrogen) separation is a promising technology in the renewable/hydrogen energy. Asymmetric supported membranes with thin mixed ionic-electronic conducting layers provide a high oxygen/hydrogen flux and required thermochemical stability. Ni-Al alloy foam substrates are attractive due to their high mechanical strength, corrosion stability and compatibility with reactors materials [1]. In this work results of authors’ studies in design and testing asymmetric supported oxygen and hydrogen membranes in catalytic processes of biofuels transformation and modeling their performance (in part summarized in published book and chapters [1-3]) are reviewed. Unique Ni-Al foam substrates with graded porosity were used for design of such membranes [1], which allowed to minimize gas diffusion resistance. Nanocomposites with mixed ionic-electronic conductivity were applied as permselective layers for oxygen separation (perovskite+fluorite, spinel+fluorite combinations) or hydrogen separation (Ni-Cu nanoalloys + Ln tungstates, niobates etc. protonic conductors). A complex of sophisticated physical methods applied to elucidate relations between their nanostructure and transport properties allowed to optimize their composition and preparation/supporting route, thus providing a high oxygen/hydrogen permeation as well as compatibility with substrate. Nanocomposite active components comprised of complex perovskites, fluorites or spinel oxides with a high lattice oxygen mobility and NiCo nanoparticles possessing a high activity and coking stability in biofuels transformation into syngas were designed and supported on the permselective membrane layers or heat-conducting honeycomb substrates placed in catalytic membrane reactors. For catalytic oxygen-permeable membrane reactors a high oxygen flux (up to 15 cm3 O2/cm2min) was achieved under air/CH4 (+CO2 + biofuel) feeds gradients at ~ 900 oC, providing a high yield of syngas. For reactors with hydrogen-permeable membranes a better performance was achieved with honeycomb catalyst put upstream, so at ~ 800 oC complete EtOH conversion in steam reforming and a high hydrogen permeation (up to 3 cm3 H2 /cm2 min) were demonstrated. Membranes remained stable without any deterioration of performance or coke deposition. Mathematic modeling using modern software (COMSOL Multiphysics, CFD), step-wise reaction scheme of fuels reforming and mass transport equations

Библиографическая ссылка: Sadykov V.A. , Eremeev N.F. , Bespalko Y.N. , Bobrova L.N.
Asymmetric Supported Membranes for Oxygen and Hydrogen Separation: Design and Performance in Catalytic Reactors for Syngas and Hydrogen Generation from Biofuels
71st Canadian Chemical Engineering Conference 24-27 Oct 2021