Faisal Shah, Ebaid Reham, Xiong Min, Huang Jin, Wang Qingyuan, El-Hefnawy Mohamed, Abomohra Abdelfatah
Department of Environmental Engineering, School of Architecture and Civil Engineering, Chengdu University, Chengdu 610106, PR China; Institute of New Energy and Low-carbon Technology, Sichuan University, Chengdu 610065, PR China.
Institute of New Energy and Low-carbon Technology, Sichuan University, Chengdu 610065, PR China.
Sci Total Environ. 2023 Feb 1;858(Pt 3):159984. doi: 10.1016/j.scitotenv.2022.159984. Epub 2022 Nov 8.
Anaerobic digestion of lignocelluloses for biogas production is greatly restricted by the poor biomass degradability. Herein, a novel approach is suggested to enhance the energy recovery from rice straw through a two-step conversion using eggshell-based catalytic pyrolysis followed by biochar-based anaerobic co-digestion. Pyrolysis with eggshell significantly enhanced the crude bio-oil yield by 4.6 %. Anaerobic digestion of rice straw using 4 g L of rice straw biochar (RB) showed the highest recorded biogas yield of 503.7 L kg VS, with 268.6 L kg VS biomethane yield. However, 4 g L of calcium-enriched eggshell rice straw biochar (ERB) enhanced the biomethane yield to 281.8 L kg VS, which represented 95.6 % higher than the control. It was attributed to enhancement of biomethanation, which resulted in 74.5 % maximum recorded biomethane content at the 7th day of anaerobic digestion. Microbial analysis confirmed that Methanosarciniales was the most dominant Archael group in the control (14.84 %), which increased sharply to 73.91 % and 91.66 % after addition of 4 g L RB and ERB, respectively. The suggested route enhanced the energy recovery in the form of bio-oil and biomethane by 41.6 %.
木质纤维素的厌氧消化用于生产沼气，因生物质降解性差而受到极大限制。在此，提出了一种新方法，通过两步转化提高稻草的能量回收率，即先进行基于蛋壳的催化热解，然后进行基于生物炭的厌氧共消化。用蛋壳进行热解显著提高了粗生物油产量4.6%。使用4 g/L稻草生物炭（RB）对稻草进行厌氧消化，记录到的最高沼气产量为503.7 L/kg挥发性固体（VS），生物甲烷产量为268.6 L/kg VS。然而，4 g/L富含钙的蛋壳稻草生物炭（ERB）将生物甲烷产量提高到281.8 L/kg VS，比对照高出95.6%。这归因于生物甲烷化的增强，在厌氧消化第7天，生物甲烷含量最高达到74.5%。微生物分析证实，甲烷八叠球菌目是对照中最主要的古菌组（14.84%），添加4 g/L RB和ERB后分别急剧增加到73.91%和91.66%。所建议的途径使生物油和生物甲烷形式的能量回收率提高了41.6%。
