纤维素超低酸水解产物的分析

Analysis of cellulose hydrolysis products in extremely low acids

基于木质纤维素类生物质水解为人类提供乙醇等能源、化工产品的重要性,该文以定量滤纸模拟生物质的主要组分-纤维素,以其超低酸水解试验得到的最佳工况下液体产物和固体残渣为研究对象,通过高效液相色谱(HPLC)结合KS-802糖柱对产物质中糖的种类进行了划分,以GC-MS对副产物进行定性,并通过扫描电镜(SEM)及热重和工业分析元素分析对固体残渣作了从表观到内部的研究,发现纤维素超低酸水解主要生成纤维四糖、三糖和二糖等低聚糖和葡萄糖及果糖,反应副产物有糠醛、羟甲基糠醛、乙酰丙酸及一些小分子酮、醛类和酸类极性化合物,水解残渣已完全改变了原始形貌,热裂解活性增强,残留物中碳和灰分含量有较大增加,最后根据分析结果探讨了纤维素超低酸水解的反应途径,为木质纤维素类生物质水解技术的规模化利用打下基础。

For the great significance of renewable energy and chemicals providing from lignocellulosic biomass hydrolysis, the quantitative paper was chosen as the model of cellulose which was the main component of lignocellulosic biomass, and its liquid products and solid residues of the optimum experimental conditions of cellulose hydrolysis in extremely low acids were chosen as the material, sugar types of the liquid products were classified by the HPLC combined with KS-802 column, and the by-products were analyzed by GC-MS qualitatively. Simultaneously the residues were observed by SEM, combined with thermogravimetric analysis, etc. from appearance to element distribution. It is observed that the main products of cellulose hydrolysis in extremely low acids are cellotetraose, cellotriose, cellobiose, glucose and fructose. The by-products are fufural, HMF, levulinic acid and some polarity compounds including ketone, aldehyde and acids. The original shape of the residues changed thoroughly and its pyrolysis reactivity, carbon and ash content increased. Finally the reaction pathways were discussed according to the analysis results so as to provide the basis for the large-scale utilization of biomass hydrolysis.