Si Hongyu, Zhao Changkai, Wang Bing, Liang Xiaohui, Gao Mingjie, Jiang Zhaoxia, Yu Hewei, Yang Yuanyuan, Gu Zhijie, Ogino Kenji, Chen Xiuxiu
Shandong Provincial Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China.
Shandong Provincial Key Laboratory of Biomass Gasification Technology, Energy Research Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, 250014, China; Graduate School of Bio-Applications and Systems Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Nakacho, Koganei-shi, Tokyo, 184-8588, Japan.
J Environ Manage. 2023 Jun 1;335:117567. doi: 10.1016/j.jenvman.2023.117567. Epub 2023 Feb 27.
Returning straw-like agricultural waste to the field by converting it into hydrochar through hydrothermal carbonization (HTC) is an important way to realize resource utilization of waste, soil improvement, and carbon sequestration. However, the large-scale HTC is highly limited by the large water consumption and waste liquid pollution. Here, we propose strategies to optimize the liquid-solid ratio (LSR) of HTC, and comprehensively evaluate the stability, soil application potential, and economic benefits of corn stover-based hydrochar under different LSRs. The results showed that the total amount of dissolved organic carbon of hydrochars increased by 55.0% as LSR reducing from 10:1 to 2:1, while the element content, thermal stability, carbon fixation potential, specific surface area, pore volume, and functional group type were not obviously affected. The specific surface area and pore volume of hydrochar decreased by 61.8% and 70.9% as LSR reduced to 1:1, due to incomplete carbonization. According to the gray relation, hydrochar derived at LSR of 10:1 and followed by 2:1 showed greatest relation degree of 0.80 and 0.70, respectively, indicating better soil application potential. However, reducing LSR from 10:1 to 2:1 made the income of single process production increased from -388 to 968 ¥, and the wastewater generation decreased by 80%. Considering the large-scale application of HTC in fields for farmland improvement and environmental remediation, the comprehensive advantages of optimized LSR will be further highlighted.
通过水热碳化（HTC）将稻草状农业废弃物转化为水炭并返还田间，是实现废弃物资源利用、土壤改良和碳固存的重要途径。然而，大规模的HTC受到大量水消耗和废液污染的严重限制。在此，我们提出优化HTC液固比（LSR）的策略，并全面评估不同LSR下基于玉米秸秆的水炭的稳定性、土壤应用潜力和经济效益。结果表明，随着LSR从10:1降至2:1，水炭中溶解有机碳总量增加了55.0%，而元素含量、热稳定性、固碳潜力、比表面积、孔隙体积和官能团类型均未受到明显影响。当LSR降至1:1时，由于碳化不完全，水炭的比表面积和孔隙体积分别下降了61.8%和70.9%。根据灰色关联度，LSR为10:1和2:1时制备的水炭与土壤的关联度分别为0.80和0.70，表明其土壤应用潜力较好。然而，将LSR从10:1降至2:1，单流程生产收入从-388元增加到968元，废水产生量减少了80%。考虑到HTC在农田改良和环境修复领域的大规模应用，优化LSR的综合优势将进一步凸显。
