Comparison of corncob-derived solid acids and evaluation of catalytic cellulose hydrolysis performance in LiBr

• Published in: Biomass conversion and biorefinery Vol. 14; no. 2; pp. 2019 - 2031
• Main Authors: Liang, Chen, Du, Chunhua, Wu, Xianli, Wang, Ju, Xu, Jie, Hu, Pengyu, Qu, Wangda
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 2024; Springer Nature B.V
• Subjects: Acids; Biotechnology; Catalysts; Catalytic activity; Cellulose; Chemical analysis; Energy; Fourier transforms; Furfural; Hydrolysis; Infrared analysis; Lignin; Lithium; Original Article; Renewable and Green Energy; Residues; Thermogravimetric analysis; Titration; Waste utilization; LiBr molten salt; Corncob; Catalysis; Cellulose hydrolysis; Carbon-based solid acid
• ISSN: 2190-6815; 2190-6823
• DOI: 10.1007/s13399-022-02322-6

In order to enhance the valorization of corncob, corncob-based solid acid catalysts were prepared via the method of partial carbonization followed by sulfonation. The prepared acid catalysts were either derived from raw corncob (hemicellulose, cellulose, and lignin), or its residues after different pretreatments, i.e., furfural residue (cellulose and lignin) and hydrolysis residue (humins and lignin), to investigate the components’ effect on the performance of solid acid. These catalysts were characterized by thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), nitrogen adsorption/desorption analysis, scanning electron microscope (SEM), elemental analysis, and acid–base titration. The analysis results suggested that the solid acid (Catalyst-3) derived from the hydrolysis residue had the best performance, with a BET surface area of 338.23 m
2
 g
−1
and total acid densities of 6.43 mmol g
−1
. This results indicated –SO
3
H groups were loaded onto the catalyst successfully. The catalytic activity was tested by cellulose hydrolysis in lithium bromide trihydrate solution (LBTH) system. The yield of glucose was as high as 80.1% at the temperature of 110 °C for 10 h. Moreover, the prepared solid acid had the advantages of easy separation, mild reaction, and producing less by-products compared with traditional liquid acids. This work provides a promising strategy for corncob waste utilization and cellulose efficient hydrolysis, which is of great significance for biomass valorization and conversion.