High Acid Biochar-Based Solid Acid Catalyst from Corn Stalk for Lignin Hydrothermal Degradation

• Published in: Polymers Vol. 12; no. 7; p. 1623
• Main Authors: Jiang, Qimeng, Yang, Guihua, Kong, Fangong, Fatehi, Pedram, Wang, Xiaoying
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 21.07.2020; MDPI
• Subjects: Aromatic compounds; Biomass; Carbon; Carbonation; Catalysts; Chemical industry; Chemical synthesis; Chromatography; corn stalk; Degradation; Experiments; Functional groups; high acid amount; large specific surface area; Lignin; lignin degradation; Morphology; Nitrogen; Phenols; solid acid catalyst; Specific surface; Spectrum analysis; Surface area; Beijing China; Switzerland; China; Japan; Germany
• ISSN: 2073-4360; 2073-4360
• DOI: 10.3390/polym12071623

Solid acid catalysts generally show the disadvantage of low acid amount and low recycling rate. To solve these problems, corn stalk-based solid acid catalysts were synthesized through carbonization and sulfonation processes in this work. The results showed that besides the rod-like structure inherited from raw corn stalk, the catalysts contained some small broken pieces on the surface, and the specific surface area varied from 1120 to 1640 m2/g. The functional groups (-SO3H) were successfully introduced onto the surface of the obtained solid acid catalysts. The acid amount varied between 1.2 and 2.4 mmol/g, which was higher than most of solid acid catalysts. The catalyst produced at 800 °C for 6 h in carbonation and then at 150 °C for 8 h in sulfonation had larger specific surface area and more sulfonate groups. In the degradation of lignin, the use of catalyst led to the generation of more aromatic compounds (65.6 wt. %) compared to that without using the catalyst (40.5 wt. %). In addition, a stable yield of reaction (85%) was obtained after four reuses. Therefore, corn stalk is suitable for high-value utilization to prepare high-acid amount biochar-based catalyst.