Exploring the potential of red mud and beechwood co-processing for the upgrading of fast pyrolysis vapours

• Published in: Journal of analytical and applied pyrolysis 2017-11, Vol.128, p.35-43
• Main Authors: Gupta, Jyoti, Papadikis, Konstantinos, Kozhevnikov, Ivan V., Konysheva, Elena Yu
• Format: Article
• Language: English
• Subjects: Beechwood; Biomass conversion; Constituent oxides: α-Al2O3; Fast pyrolysis; Fe2O3; Py-GC/MS; Red Mud (Bauxite mining waste); SiO2; TiO2
• ISSN: 0165-2370; 1873-250X
• DOI: 10.1016/j.jaap.2017.11.002

[Display omitted] •Thermal treatment of red mud impacts fast pyrolysis product distribution.•Total yield of phenols reduced during catalytic vapour upgrading.•Moderate selectivity of red mud to furfurals was revealed.•Red mud shows higher catalytic activity than individual oxides. Red mud, a by-product of the Bayer process in the aluminium industry, is co-processed with beechwood for the in-situ upgrading of fast pyrolysis vapour products. It is revealed that the co-processing of beechwood with thermally pre-treated red mud enhanced the vapour upgrading effect. Individual oxides (α-Al2O3, Fe2O3, SiO2, and TiO2), which are the main constituents of red mud were also tested for the identification of their individual impact on the upgrading process. A biomass/catalyst weight ratio of 1:4 showed the strongest effect on the product distribution. Red mud was found to reduce the yield of phenolic compounds and promote the formation of cellulose- and hemicellulose-derived furfurals and hemicellulose-derived acetic acid, which can be used for the production of a broad range of chemicals and liquid transportation fuels. α-Al2O3 and Fe2O3 reduced the relative yield of phenols as well, whereas the formation of furfurals was promoted by Fe2O3 and TiO2. SiO2 showed negligible effect on fast pyrolysis vapours. The impact of catalysts on the product distribution is discussed for phenols, furfurals, and acids, for which the strongest effects were observed.