Biodiesel and hydrodeoxygenated biodiesel autothermal reforming over Rh-containing structured catalyst

• Published in: Catalysis today 2021-11, Vol.379, p.42-49
• Main Authors: Shilov, V.A., Rogozhnikov, V.N., Ruban, N.V., Potemkin, D.I., Simonov, P.A., Shashkov, M.V., Sobyanin, V.A., Snytnikov, P.V.
• Format: Article
• Language: English
• Subjects: Autothermal reforming; Biodiesel; Ceria-zirconium oxide; Rhodium; Structured catalyst; Synthesis gas
• ISSN: 0920-5861; 1873-4308
• DOI: 10.1016/j.cattod.2020.06.080

[Display omitted] •Composite Rh/Zr0.25Ce0.75O2/FeCrAl wire mesh catalyst with high Rh dispersion.•High performance in autothermal reforming (ATR) of hydrodeoxygenated biodiesel and 9-aged biodiesel.•Syngas productivity in biodiesel and ATR: 2.5 m3Lcat−1 h−1.•Long-term storage of biodiesel led to incomplete conversion due to a large content of polymeric compounds. In this study, new results of comparative research on autothermal reforming(ATR) of biofuels (hydrodeoxygenated biodiesel and long- stored biodiesel) over composite RhSC catalysts (0.24 wt.% Rh supported on structured Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl carrier) were obtained. The impact of fuel chemical composition on the catalyst performance was discussed. Hydrodeoxygenated biodiesel mainly consisted of heptadecane, other normal alkanes and small amounts of alkenes together with a portion of unreacted fatty acid ethers. RhSC exhibited syngas productivity of about 2.5 m3Lcat−1 h−1 (STP) at complete conversion of hydrodeoxygenated biodiesel without considerable by-products formation, at molar ratios O2/C = 0.54, H2O/C = 3, T =750 °C and GHSV =5000 h−1. The catalyst exhibited stable operation and no coke formation for at least 90 h on stream. Biodiesel after nine years storage, which was used in this study, contained methyl esters of saturated and unsaturated fatty acids and a large proportion of polymeric compounds. It was successfully demonstrated that even this aged biodiesel can be converted to synthesis gas over the developed Rh/Ce0.75Zr0.25O2-δ-ƞ-Al2O3/FeCrAl structured catalyst. Further optimization of the catalyst and reaction conditions (higher temperature, lower GHSV, catalyst doping by promoters) is required for reaching efficient reforming of the aged biodiesel. Nevertheless, it was demonstrated that biodiesel and hydrodeoxygenated biodiesel, which combine high energy density and renewability, were very attractive biofuels for fuel cell-based power unit applications.