Enhanced Biogas Production from Rice Husk via Mesophilic Anaerobic Digestion Using Water Chestnut Shell-Derived Activated Biochar
نویسندگان
1 Graduate Institute of Environmental Engineering, Faculty of Engineering, National Taiwan University, P. O. Box: 106319, Taipei, Taiwan, R.O.C.
2 Department of Environmental Engineering and Management, Faculty of Engineering, Chaoyang University of Technology, P. O. Box: 413310, Taichung, , Taiwan, R.O.C.
3 Department of Environmental Engineering and Management, Faculty of Engineering, Chaoyang University of Technology, P. O. Box: 413310, Taichung, , Taiwan, R.O.C.
4 Department of Environmental Engineering, Faculty of Engineering, University of Southampton, P. O. Box: SO17 1BJ, Southampton, United Kingdom.
5 Department of Environmental Engineering and Management, Faculty of Engineering, Chaoyang University of Technology, P. O. Box: 413310, Taichung, , Taiwan, R.O.C.
6 Graduate Institute of Environmental Education and Management, Faculty of Science, National Taichung University of Education, P. O. Box: 40306, Taichung, Taiwan, R.O.C.
7 Department of Environmental Engineering, Faculty of Engineering, National Ilan University, P. O. Box: 260007, Yilan County, Taiwan, R.O.C.
8 Department of Environmental Engineering and Management, Faculty of Engineering, Chaoyang University of Technology, P. O. Box: 413310, Taichung, , Taiwan, R.O.C.
doi
10.30501/jree.2025.514973.2342چکیده
This study examines the impact of adding chestnut shell biochar (WCSB) to rice husk (RH) in mesophilic anaerobic digestion systems to enhance biogas production. Biochar produced at 250°C, 450°C, and 750°C was added at 0, 0.7, 1.4, and 2.8 g per reactor, equivalent to 0, 0.035, 0.07, and 0.14 g biochar/g volatile solids (VS). Among the tested conditions, 2.8 g of WCSB yielded the highest biogas production. For WCSB produced at 250°C, the biogas outputs were 39.76, 28.99, 29.33, and 26.13 mL/g VS; at 450°C, 40.86, 29.69, 28.33, and 26.13 mL/g VS; and at 750°C, 41.63, 29.38, 27.18, and 26.13 mL/g VS for the same respective doses. The results suggest that higher biochar dosage and pyrolysis temperature improve gas yield due to increased surface area and buffering capacity. Modified Gompertz modeling confirmed the highest production potential (A = 41.02 mL/g VS) and rate (μₘ = 2.912 mL/g·d) at 2.8 g, particularly with WCSB produced at 750°C. The addition of biochar also stabilized pH (5.83–6.70), maintained a favorable oxidation–reduction potential (ORP: –200 to –348 mV), and slightly increased electrical conductivity (1.94–2.61 µS/cm), all of which supported the anaerobic digestion process. These findings demonstrate that WCSB can serve as a practical additive for improving the efficiency of biogas production from agricultural residues.
