Faculty Publications

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Author: search.filters.author.Dutta, S.Subject: search.filters.subject.catalysis

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    Energy Densification of Biomass-Derived Furfurals to Furanic Biofuels by Catalytic Hydrogenation and Hydrodeoxygenation Reactions
    (Multidisciplinary Digital Publishing Institute (MDPI), 2021) Vinod, N.; Dutta, S.
    The concomitant hydrolysis and dehydration of biomass-derived cellulose and hemicellulose to furfural (FUR) and 5-(hydroxymethyl)furfural (HMF) under acid catalysis allows a dramatic reduction in the oxygen content of the parent sugar molecules with a 100% carbon economy. However, most applications of FUR or HMF necessitate synthetic modifications. Catalytic hydrogenation and hydrogenolysis have been recognized as efficient strategies for the selective deoxygenation and energy densification of biomass-derived furfurals generating water as the sole byproduct. Efficient and eco-friendly catalysts have been developed for the selective hydrogenation of furfurals affording renewable furanic compounds such as 2-methylfuran, 2,5-dimethylfuran and 2-methyltetrahydrofuran with potential applications as biofuel, solvent and chemical feedstock. Hydrogen gas or hydrogen donor molecules, required for the above processes, can also be renewably obtained from biomass using catalytic processes, enabling a circular economy. In this review, the recent developments in the energy densification of furfurals to furanic compounds of commercial significance are elaborated, emphasizing the role of catalyst and the reaction parameters employed. Critical discussion on sourcing hydrogen gas required for the processes, using hydrogen donor solvents, catalyst design and the potential markets of furanic intermediates have been made. Critical evaluations of the accomplishments and challenges in this field are also provided. © 2021 by the authors.
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    Efficient and Scalable Production of Alkyl Levulinates from Cellulose-Derived Levulinic Acid Using Heteropolyacid Catalysts
    (Wiley-Blackwell info@wiley.com, 2019) Onkarappa, S.B.; Javoor, M.; Mal, S.S.; Dutta, S.
    This work reports a straightforward and scalable synthesis of a series of alkyl levulinates from cellulose-derived levulinic acid and alkyl alcohols using commercially available heteropolyacid catalysts under homegenous conditions. The reaction was optimized on parameters such as temperature, molar ratio of reagents, type and loading of catalyst. The solvent-free reactions afforded alkyl levulinates in high isolated yields (>85%) using only slight excess of alcohols and 10 wt% of catalyst at 120 °C in 6 h. Further, the catalysts were successfully recycled for three consecutive cycles without significant loss in activity. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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    Efficient Preparation of Alkyl Benzoates by Heteropolyacid-Catalysed Esterification of Benzoic Acid under Solvent-Free Condition
    (Wiley-Blackwell, 2019) Tiwari, R.; Rahman, A.; Bhat, N.S.; Onkarappa, S.B.; Mal, S.S.; Dutta, S.
    This study reports a high-yielding, solvent-free, and scalable synthesis of alkyl benzoates from benzoic acid and its derivatives using heteropolyacids (HPA) as efficient and recyclable acid catalysts. The alkyl benzoates were obtained in excellent isolated yields (>85%) within 4 h at 120 °C using 1.5 equivalent of the alcohol reagent and only 0.4 mol% of the phosphotungstic acid (PTA) catalyst. The PTA catalyst was conveniently recovered and reused for three consecutive cycles without significant loss in mass or activity. © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
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    Production of 5-(formyloxymethyl)furfural from biomass-derived sugars using mixed acid catalysts and upgrading into value-added chemicals
    (Elsevier Ltd, 2020) Dutta, S.
    In this work, 5-(formyloxymethyl)furfural (FMF) has been produced from biomass-derived hexose sugars within a biphasic reaction mixture consisting of aqueous formic acid (85%), a strong Brønsted acid catalyst, and 1,2-dichloroethane as an organic extractant. Using a combination of aqueous hydrobromic acid and formic acid, under optimized condition (80 °C, 8 h, 10 wt% substrate loading), 68% isolated yield of FMF was obtained from fructose. FMF has been demonstrated as a renewable chemical building block for the synthesis of renewable chemicals of commercial significance such as 5-methylfurfural, 2,5-diformylfuran, and 2,5-furandicarboxylic acid in good to excellent isolated yields. © 2020 Elsevier Ltd