酸性水溶助剂对竹屑组分分离的研究

Fractionation of Bamboo Residues by Acid Hydrotrope

研究酸性水溶助剂对甲苯磺酸(p-TsOH)对竹屑组分分离及制备单糖、木质素纳米颗粒和糠醛的影响。通过扫描电镜(SEM)、X射线衍射(XRD)、红外光谱(FT-IR)对竹屑分离前后物理化学结构进行分析,采用透射电镜(TEM)对木质素纳米颗粒进行分析。研究结果表明:在p-TsOH质量分数为55%、温度90℃和120 min条件下,木聚糖和木质素去除率分别为82.72%和82.16%,而纤维素保留率高达87.3%,预处理物料酶解72 h的葡萄糖得率达96.4%;预处理后分离得到的滤液采用缓慢加水稀释沉淀法得到木质素纳米颗粒(平均粒径为69.33 nm)后,再采用真空蒸发浓缩后于170℃、5 min下反应制备糠醛,糠醛得率为78.5%。物料衡算结果表明:1000 g绝干竹屑可以得到426.6 g可发酵性单糖(其中葡萄糖390.9 g,木糖35.7 g),217.1 g木质素纳米颗粒和85.4 g糠醛。

The effects of acid hydrotrope(p⁃toluenesulfonic acid(p⁃TsOH))on the fractionation of bamboo residues,and the preparation of monosaccharides,lignin nanoparticles and furfural were investigated.The physicochemical structure variations of bamboo residues before and after the pretreatment were analyzed using scanning electron microscopy(SEM),X⁃ray diffraction(XRD)and infrared spectroscopy(FT⁃IR),and the lignin nanoparticles were analyzed by transmission electron microscopy(TEM).Under the conditions of p⁃TsOH mass fraction of 55%,temperature of 90°C and pretreatment time of 120 min,the results showed that the removal rates of xylan and lignin were 82.72%and 82.16%respectively,while the retention rate of cellulose was as high as 87.3%.The glucose yield was 96.4%after 72 h enzymatic hydrolysis.After pretreatment,the spent liquor was diluted by slowly adding water to precipitate the lignin nanoparticles(with an average particle size of 69.33 nm).The liquid after lignin precipitation was concentrated by vacuum evaporation.Furfural was then prepared by subjecting the concentrated liquid to a reactor at 170°C for 5 min,and the yield of furfural was 78.5%.The results of mass balance demonstrated that 1000 g dried bamboo residues could produce 426.6 g of fermentable sugars(including 390.9 g glucose and 35.7 g xylose),217.1 g lignin nanoparticles and 85.4 g furfural.