Bian Ai-Qin, Yuan Ye, Zhang Lu-Lu, Fu Qiang, Chen Tian-Ming, He Lei, Dind Cheng, Wang Ai-Jie
School of Environmental Science and Engineering, Yancheng Institute of Technology, Yancheng 224051, China.
Key Laboratory of Environmental Biotechnology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
Huan Jing Ke Xue. 2019 Feb 8;40(2):1003-1010. doi: 10.13227/j.hjkx.201807092.
To obtain a high methane yield during the anaerobic digestion of a straw and animal manure mixture, an integrated process of thermo-alkali-bi-enzyme hydrolysis-anaerobic digestion was proposed. A mixture of corn straw and cattle manure was selected as the experimental object. A higher dissolution efficiency of cellulose, hemicellulose, and protein in the thermo-alkali pretreatment, dosages and hydrolysis times of cellulase and protease in the bi-enzyme hydrolysis, and the methane yield and biogas production cycle in the anaerobic digestion with mixed slurry and hydrolysates were investigated respectively. The results showed that the dissolution efficiency (%TS) of cellulose (24.84%), hemicellulose (12.24%), and protein (8.92%) reached their highest levels at 0.5% NaOH and 80℃ (compared with the control group). The bi-enzyme hydrolysis process and conditions were as follows:cellulase hydrolysis was 80 U·g and 18 h, and protease hydrolysis was 20 U·g and 4 h. The hydrolysis efficiency of cellulose and protein reached 74.08% and 74.01%, respectively. The sugars in the hydrolysate were increased by 12-32 times. During anaerobic digestion, the maximum yield of methane from hydrolysate after thermo-alkali-bi-enzyme hydrolysis was 750 mL·h, and the gas production cycle was 50 h. Compared with the mixture after the thermo-alkali pretreatment, the methane production efficiency of the mixed hydrolysate after thermo-alkali-bi-enzyme hydrolysis was increased by 14 times, and the gas production cycle was noticeably shortened by 17 d. The results indicated that the thermo-alkali and enzyme hydrolysis pretreatment could effectively accelerate the hydrolysis rate in the anaerobic digestion with the mixture. The results of this study provide a new reference for developing efficient technology of high-value energy utilization of agricultural waste.
为了在秸秆与畜禽粪便混合物的厌氧消化过程中获得高甲烷产量，提出了一种热碱 - 双酶水解 - 厌氧消化集成工艺。选取玉米秸秆与牛粪的混合物作为实验对象，分别考察了热碱预处理中纤维素、半纤维素和蛋白质的较高溶解效率，双酶水解中纤维素酶和蛋白酶的用量及水解时间，以及混合浆液和水解产物厌氧消化过程中的甲烷产量和产气周期。结果表明，在0.5%NaOH和80℃条件下，纤维素（24.84%）、半纤维素（12.24%）和蛋白质（8.92%）的溶解效率（%TS）达到最高水平（与对照组相比）。双酶水解工艺及条件如下：纤维素酶水解为80 U·g和18 h，蛋白酶水解为20 U·g和4 h。纤维素和蛋白质的水解效率分别达到74.08%和74.01%。水解产物中的糖类增加了12 - 32倍。在厌氧消化过程中，热碱 - 双酶水解后水解产物的甲烷最大产量为750 mL·h，产气周期为50 h。与热碱预处理后的混合物相比，热碱 - 双酶水解后混合水解产物的甲烷产率提高了14倍，产气周期明显缩短了17 d。结果表明，热碱和酶水解预处理能有效加速混合物厌氧消化中的水解速率。本研究结果为开发农业废弃物高值能源利用的高效技术提供了新的参考。
