1. Enhanced 5-hydroxymethylfurfural production from cellulose in monophasic molten salt hydrate: Insights into the effect of catalyst acidity on conversion.
- Author
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Ma, Qiaozhi, Liang, Haotong, Lin, Jianying, and Liu, Qiyu
- Subjects
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CROSSLINKED polymers , *ACIDITY , *BRONSTED acids , *LEWIS acids , *FUSED salts , *CATALYSTS , *CELLULOSE - Abstract
[Display omitted] • Cellulose can be selectively converted into 5-HMF in monophasic MSH solvent. • 44.5 % yield of 5-HMF together with 75.0 % of carbon balance were obtained. • The total B/L acid sites of AlSiO-20 is the key issue in affecting 5-HMF yield. • AlSiO-20 can be recycled for more than 5 times with stable performance. • 5-HMF can be separated from MSH via HCP adsorption. Production of 5-HMF from cellulose is a promising approach for advanced bio-fuels preparation, but the degradation of active 5-hydroxymethylfurfural (5-HMF) is a critical challenge affecting 5-HMF selectivity. To address this issue, biphasic reaction system consisting of water and organic solvent is generally used to in-situ extract 5-HMF into organic phase to inhibit product degradation. Despite the high 5-HMF selectivity achieved in biphasic system, low product concentration and difficulty in separation restrict its industrial applications. Molten salt hydrate (MSH) is unique in cellulose conversion and 5-HMF preservation. In this work, MSH of LiBr was used as monophasic solvent for cellulose conversion and an acidity tunable solid acid AlSiO-x was used as the catalyst. It was found that a relatively high 5-HMF yield of 44.5% together with carbon balance of 75.0% were obtained at 170 °C for 20 min, which is higher than the results ever reported. Importantly, this work proved that the ratio of total Brønsted to Lewis acid sites on solid acid is the key issue affected 5-HMF yield. After reaction, solid acid can be recycled for more than 5 times without catalytic performance decline, and the dissolved 5-HMF can be sufficiently separated from MSH via hyper cross-linked polymer (HCP) adsorption. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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