摘要
为研究温度-压力解耦条件下汽爆玉米秸秆物化作用及其酶解效果,分别采用不同蒸煮温度(453、471和485 K)和不同爆破压力(1.0、1.5和2.0MPa)对玉米秸秆进行汽爆处理,测定并分析对其物理结构(微观形貌和多孔特性)、化学组成(组分含量、官能团结构和结晶程度)和热力学性质的影响。结果显示:随蒸煮温度增加,汽爆秸秆中半纤维素和乙酰基含量最高降低50.69%和67.11%,木质素含量最高增加17.66%,整体热稳定性增加;水洗液中糖类产物含量最高降低45.37%,而有机酸和糠醛类含量最高增加37.66%和73.21%。随爆破压力增加,汽爆秸秆多孔特性得到改善,具体表现为累积孔体积、累积孔面积、平均孔径、孔隙率、渗透率和迂曲度均有不同程度增加。汽爆水热改性作用对提升秸秆酶解效果的贡献大于其物理爆破作用,但在较高温度条件下对结构性成分的过度降解可能导致回收率降低,从而影响葡萄糖得率。在471 K低温维持和2.0 MPa高压爆破条件下,汽爆秸秆纤维素水解率最高达到87.99%,表明温压分控汽爆预处理策略有效促进秸秆纤维素酶解转化。研究可为揭示木质纤维素类物料汽爆过程物化作用机理、提高预处理和后续转化利用效果提供理论依据。
This study aims to clarify the physicochemical properties and enzymatic digestibility of Steam Exploded(SE)maize stalk under the conditions of steaming temperature-explosion pressure decoupling during bioethanol production.A SE pretreatment was conducted at low-temperature maintenance,followed by pressure lifting and decompression,in order to realize the decoupling of steaming temperature and explosion pressure.Three treatments were performed to determine the hydrothermal effects of SE on the chemical properties of maize stalk at the cooking temperatures(453,471,and 485 K),and the explosion pressure of 2.0 MPa.Another three treatments were also performed to explore the physical explosion effects of SE on the physical properties of maize stalk at the explosion pressures(1.0,1.5,and 2.0 MPa),and the cooking temperature 485 K.The retention time was fixed at 10 min in all six treatments.A systematic characterization was then conducted to analyze the physical structure(including microscopic morphology and porous properties),chemical composition(including components content,functional groups,and degree of crystallinity),and thermodynamic properties of SE maize stalk.The results showed that the contents of hemicellulose and acetyl decreased by 50.69%and 67.11%,respectively,whereas,the content of lignin increased by 17.66%,in the solid fraction of SE maize stalk with the increment of steaming temperature.In the liquid fraction,the content of carbohydrates decreased by 45.37%,while the contents of organic acids and furfurals increased by 37.66%and 73.21%,respectively.The thermogravimetric analysis showed that the higher the steaming temperature was,the greater the peak height and area of pyrolysis III stage were.It infers that the degradation rate and weight loss rate of SE maize stalk were greater than the original,indicating better thermal stability.The porous properties of SE maize stalk were also improved to different extents,with the increment of explosion pressure.Specifically,the cumulative pore volume and pore are
作者
李祥
陆子琦
浦译文
李冉冉
贾永秀
Amirsalar Khandan
隋文杰
Li Xiang;Lu Ziqi;Pu Yiwen;Li Ranran;Jia Yongxiu;Amirsalar Khandan;Sui Wenjie(Jiangsu Key Laboratory for Bioresources of Saline Soils,Yancheng Teachers University,Yancheng 224007,China;School of Marine and Biological Engineering,Yancheng Teachers University,Yancheng 224007,China;State Key Laboratory of Food Nutrition and Safety,College of Food Science and Engineering,Tianjin University of Science&Technology,Tianjin 300457,China;AS.Khandan Mechnical Engineering Department,Islamic Azad University,Khomeyinishahr Branch,Isfahan 84175119,Iran)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2022年第3期239-246,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
江苏省盐土生物资源研究重点实验室开放课题项目(JKLBS 2020014)
国家自然科学基金青年科学基金项目(21808171)。
关键词
生物质
温度
木质素
玉米秸秆
蒸汽爆破
酶解
物化性质
biomass
temperature
lignin
maize stalk
steam explosion
enzymatic hydrolysis
physicochemical properties
