Shi Fuxi, Wang Yajun, Davaritouchaee Maryam, Yao Yiqing, Kang Kang
College of Mechanical and Electronic Engineering, Northwest A&F University, Yangling 712100, China.
Agro-Environmental Protection Institute, Ministry of Agriculture and Rural Affairs, Tianjin 300191, China.
ACS Omega. 2020 Sep 21;5(38):24780-24789. doi: 10.1021/acsomega.0c03419. eCollection 2020 Sep 29.
A major challenge in converting lignocellulose to biofuel is overcoming the resistance of the biomass structure. Herein, sequential dilute acid-alkali/aqueous ammonia treatment was evaluated to enhance enzymatic hydrolysis of poplar biomass by removing hemicellulose first and then removing lignin with acid and base, respectively. The results show that glucose release in sequential dilute acid-alkali treatments (61.4-71.4 mg/g) was 7.3-24.8% higher than sequential dilute acid-aqueous ammonia treatments (57.2-61.8 mg/g) and 283.8-346.3% higher than control (16.0 mg/g), respectively. Dilute acid treatment removed most hemicellulose (84.9%) of the biomass, followed by alkaline treatment with 27.5% removal of lignin. Roughness, surface area, and micropore volume of the biomass were crucial for the enzymatic hydrolysis. Furthermore, the ultrastructure changes observed using crystallinity, Fourier transform infrared spectroscopy, thermogravimetric analysis, and pyrolysis gas chromatography/mass spectrometry support the effects of sequential dilute acid-alkali treatment. The results provide an efficient approach to facilitate a better enzymatic hydrolysis of the poplar samples.
将木质纤维素转化为生物燃料的一个主要挑战是克服生物质结构的抗性。在此，对连续稀酸-碱/氨水预处理进行了评估，通过先去除半纤维素，然后分别用酸和碱去除木质素，来增强杨树生物质的酶促水解。结果表明，连续稀酸-碱处理中的葡萄糖释放量（61.4-71.4毫克/克）分别比连续稀酸-氨水预处理（57.2-61.8毫克/克）高7.3-24.8%，比对照（16.0毫克/克）高283.8-346.3%。稀酸处理去除了生物质中大部分（84.9%）的半纤维素，随后进行碱处理，去除了27.5%的木质素。生物质的粗糙度、表面积和微孔体积对酶促水解至关重要。此外，使用结晶度、傅里叶变换红外光谱、热重分析和热解气相色谱/质谱观察到的超微结构变化支持了连续稀酸-碱处理的效果。这些结果提供了一种有效的方法，以促进杨树样品更好的酶促水解。
