摘要
以农业废弃物玉米芯为研究对象,采用乙醇/乙二醇/1,4-丁二醇辅助的酸性低共熔溶剂(氯化胆碱/对甲基苯磺酸)进行预处理,实现了玉米芯主要组分的高效拆解并促进了其纤维素的酶水解转化。采用扫描电子显微镜(SEM)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、比表面积检测(BET)考察了不同反应体系的温度对玉米芯木聚糖/木质素脱除及纤维素酶水解的影响。实验结果表明:3种低共熔体系均可实现半纤维素的高效脱除,最高脱除效率达98.24%(乙二醇三元体系);与添加二元醇的体系相比,乙醇辅助的三元体系中木质素的脱除效率最高(94.53%),而丁二醇辅助的三元体系中纤维素的回收率最高(81.69%)。SEM和BET结果显示,与未处理的原料相比,预处理后底物纤维呈现明显卷曲、折叠和多孔结构,随着温度的升高,碎片化程度及比表面积明显增加。XRD分析表明,纤维素的结晶度均上升,而晶型结构仍为天然Ⅰ型。FT-IR结果显示,随着半纤维素及木质素的大量脱除,相关特征峰的信号明显减弱。酶水解结果显示,乙二醇辅助的三元体系预处理底物的纤维素酶水解效率最高,达到99.40%。因此,醇辅助的酸性低共熔溶剂体系可在温和条件下高效脱除玉米芯半纤维素及木质素组分,并大幅度提升其纤维素的酶水解效率,有望应用于开发农业废弃物的增值转化工艺中。
Lignocellulosic biomass is one of the most abundant and renewable resources in nature,being considered as an ideal source for the preparation of petroleum-based chemicals and materials.The main components of lignocellulosic biomass are cellulose,hemicellulose and lignin,in which hemicellulose and lignin are covalently cross-linked with each other and interact with cellulose by hydrogen bonds and van der Waals forces.Recently,deep eutectic solvent(DES) has been considered as an ideal solvent for biomass pretreatment,due to its advantages of simple preparation,good biocompatibility and recyclability.The acidic DES system(ADES) can efficiently remove lignin and hemicellulose while retaining most of cellulose and has gradually become a hot spot in the research field of biomass fractionation.In this study,compared with untreated corn cobs and binary DES treated residues(choline chloride/p-toluene sulfonic acid and ChCl/p-TsOH),the agricultural waste corn cob was fractionated and saccharified efficiently using ethanol/ethylene glycol(EG)/1,4-butanediol(BDO) assisted acidic deep eutectic solvents(ChCl/p-TsOH).The effect of different temperatures of alcohols-assisted ADES pretreatment on the xylan/lignin removal and cellulose enzymatic hydrolysis was investigated by the X-ray diffraction(XRD),scanning electron microscope(SEM),Fourier transform infrared(FT-IR),and Brunauer-Emmett-Teller surface area(BET).The results demonstrated that the high removal of hemicellulose(>90%) could be attained in all systems,up to 98.24%(EG).The lignin removal reached up to 94.53% in the ethanol-ADES system,as well as the maximum cellulose recovery in ethylene glycol(BDO) assisted ADES system(81.69%).The SEM images revealed that the quantities of curled,folded and porous structures emerged in pretreated residues,with a significant increase in fragmentation and specific surface area as the temperature rose.The relative crystallinity of pretreated residues was promoted,with natural Type-I cellulose crystalline structure using XRD.The FT-IR spe
作者
任静
刘旭泽
詹云妮
黄晨
房桂干
周雪莲
REN Jing;LIU Xuze;ZHAN Yunni;HUANG Chen;FANG Guigan;ZHOU Xuelian(Jiangsu Key Lab of Biomass Energy and Material,Institute of Chemical Industry of Forest Products,Chinese Academy of Forestry,Nanjing 210042,China;Jiangsu Co-Innovation Center of Efficient Processing and Utilization of Forest Resources,Nanjing Forestry University,Nanjing 210037,China)
出处
《林业工程学报》
CSCD
北大核心
2024年第6期86-92,共7页
Journal of Forestry Engineering
基金
国家自然科学基金(32301546,32371821)
江苏省自然科学基金(BK20230405)
泰山产业领军人才工程专项经费(tacy20200213)。
关键词
玉米芯
低共熔溶剂
预处理
酶水解
酶解效率
corn cobs
deep eutectic solvent
pretreatment
enzymatic hydrolysis
enzymatic efficiency
