Nanchang University, State Key Laboratory of Food Science and Technology, Nanchang 330047, China; Nanchang University, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang 330047, China.
Nanchang University, State Key Laboratory of Food Science and Technology, Nanchang 330047, China; Nanchang University, Engineering Research Center for Biomass Conversion, Ministry of Education, Nanchang 330047, China; Center for Biorefining and Department of Bioproducts and Biosystems Engineering University of Minnesota, 1390 Eckles Ave., St. Paul, MN 55108, USA.
Bioresour Technol. 2018 Mar;251:57-62. doi: 10.1016/j.biortech.2017.12.022. Epub 2017 Dec 9.
This study performed microwave-assisted acid pretreatment on pure lignin. The effects of microwave temperature, microwave time, and hydrochloric acid concentration on characteristics and pyrolysis behavior of lignin were examined. Results of ultimate analysis revealed better properties of all pretreated samples than those of raw lignin. Fourier transform infrared spectroscopy analysis showed breakage of βO4 bond and aliphatic side chain, decrease in OH groups, and formation of CO groups in pretreatment. Microwave temperature exerted more significant influence on lignin structure. Thermal stability of treated lignin was improved and insensitive to short microwave time and acid concentration under mild conditions. Resulting from improved alkyl-phenols and decreased alkoxy-phenols, microwave-assisted acid pretreatment of lignin yielded bio-oil with excellent quality. Total yield of phenols in pyrolysis vapors (200 °C) improved to 14.15%, whereas that of guaiacols decreased to 22.36%. This study shows that microwave-assisted acid pretreatment is a promising technology for lignin conversion.
本研究对纯木质素进行了微波辅助酸预处理。考察了微波温度、微波时间和盐酸浓度对木质素特性和热解行为的影响。元素分析结果表明，所有预处理样品的性能均优于原木质素。傅里叶变换红外光谱分析表明，预处理过程中βO4 键和脂肪侧链断裂，OH 基团减少，CO 基团形成。微波温度对木质素结构的影响更为显著。在温和条件下，处理后的木质素热稳定性提高，对短微波时间和酸浓度不敏感。由于烷基酚的增加和烷氧基酚的减少，微波辅助酸预处理木质素得到了具有优异品质的生物油。热解蒸汽中酚类（200°C）的总收率提高到 14.15%，而愈创木酚的收率降低到 22.36%。本研究表明，微波辅助酸预处理是一种很有前途的木质素转化技术。
