Synergistic Catalytic Effect of Sulphated Zirconia—HCl System for Levulinic Acid and Solid Residue Production Using Microwave Irradiation

The synergistic conversion of <i>Miscanthus x</i><i>Giganteous</i> with sulphated zirconia and dilute hydrochloric acid was investigated. The sulphated zirconia was prepared using H<sub>2</sub>SO<sub>4</sub> impregnation and characterised using X-ray D...

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Bibliographic Details
Published in:Energies
Main Authors: George Hurst, Juan Maria González-Carballo, Lubomira Tosheva, Silvia Tedesco
Format: Article
Language:English
Published: MDPI AG 2021-03-01
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Online Access:https://www.mdpi.com/1996-1073/14/6/1582
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Summary:The synergistic conversion of <i>Miscanthus x</i><i>Giganteous</i> with sulphated zirconia and dilute hydrochloric acid was investigated. The sulphated zirconia was prepared using H<sub>2</sub>SO<sub>4</sub> impregnation and characterised using X-ray Diffraction (XRD), Energy-dispersive X-ray (EDX), Scanning Electron Miscroscope (SEM) spectroscopy and nitrogen adsorption–desorption measurements. The microwave-assisted reaction was evaluated at various temperatures, reaction times and catalyst-to-biomass ratios, with and without the presence of trace HCl in the solution medium for the conversion of <i>Miscanthus x</i><i>Giganteous</i> to levulinic acid. The highest levulinic acid yield of 63.8% was achieved at 160 °C, 80 min and a 2:1 catalyst-to-biomass ratio, with 10 mM HCl. The catalyst recyclability was investigated with and without calcination, finding that significant humin deposition on the catalyst surface likely caused catalyst deactivation. The post-reaction solid residue was also characterised using SEM, EDX, XRD, elemental composition and nitrogen adsorption–desorption measurements. Findings indicate that this residue could potentially be used as a soil amendment or as a fuel source. The synergistic conversion of real lignocellulosic biomass with sulphated zirconia and trace hydrochloric acid showed remarkable promise and should be investigated further.
ISSN:1996-1073