Lignin-derived carbon-based solid acid catalyst for the conversion of Pueraria cellulose to lactic acid

Preparation of lactic acid (LaA) from waste biomass Pueraria cellulose by chemically catalyzed conversion is important for the realization of biomass waste resource utilization. In this study, lignin was used as raw material to prepare lignin-based carbonaceous support (LCSA) by one-step sulfonation and carbonization with chlorosulfonic acid. LCSA-AlxZny, a lignin-based carbon solid acid catalyst, was obtained by modifying the carbonaceous support with inexpensive and readily available Al and Zn chlorides. Through the use of SEM, BET, XRD, FT-IR and NH3-TPD, the catalyst's physical as well as chemical characteristics were identified. In an aqueous solution, these catalysts were evaluated for the generation of LaA from Pueraria cellulose. LCSA-Al was identified as the optimal catalyst, subsequently, experimental conditions such as reaction time, reaction temperature, and catalyst dosage were studied and optimized. The results showed that at 160 degrees C, with 50 mg Pueraria cellulose, 50 mg catalyst, and 10 mL deionized water, the conversion rate of Pueraria cellulose was 53.7% and the highest LaA yield was 24.7% after 120 min of reaction. This research provides a new pathway for the preparation of chemicals from cellulose via multi-step tandem catalytic reactions.

Automated summary

In this study, lactic acid was prepared from waste biomass Pueraria cellulose through chemically catalyzed conversion. A lignin-based carbon solid acid catalyst was obtained by modifying the carbonaceous support with Al and Zn chlorides. The optimal catalyst was identified, and the reaction conditions were optimized to achieve high conversion rate and yield of lactic acid. This research provides a new pathway for the preparation of chemicals from cellulose.