聚合氯化铝对木质纤维素MgCl_(2)预处理液的纯化  

Purification characteristics of polyaluminum chloride for MgCl_(2) prehydrolysate of lignocellulose

作　　者：韩潇[1] 霍丹[1,2,3] 谷丞 孙悦凯 司传领 裴继诚[1] 刘莹[3] HAN Xiao;HUO Dan;GU Cheng;SUN Yuekai;SI Chuanling;PEI Jicheng;LIU Ying(Tianjin Key Laboratory of Pulp and Paper,Tianjin University of Science&Technology,Tianjin 300457,China;Guangxi Key Laboratory of Clean Pulp and Paper and Pollution Control,Light Industry and Food Engineering,Guangxi University,Nanning 530004,China;Tianjin Jianfeng Natural Product R&D Co.Ltd.,Tianjin 300457,China)

机构地区：[1]天津科技大学天津市制浆造纸重点实验室,天津300457 [2]广西清洁化制浆造纸与污染控制重点实验室,广西大学轻工与食品工程学院,南宁530004 [3]天津市尖峰天然产物研究开发有限公司,天津300457

出　　处：《林业工程学报》2022年第1期94-99,共6页Journal of Forestry Engineering

基　　金：国家自然科学基金(21908167);天津市自然科学基金(18JCQNJC7570.0);广西清洁化制浆造纸与污染控制重点实验室开放基金(2021KF31)。

摘　　要：预处理是生物质资源转化的关键步骤,其过程会使植物细胞壁的结构发生变化,从而降低生物质的顽固性并增强其中糖的有效溶解,以促进其高值化利用。预处理液成分复杂,所含木质素和多种降解产物不利于糖类的高效利用,需要对其进行分离纯化。以桉木经MgCl_(2)预处理的废液为对象,通过聚合氯化铝(PAC)絮凝的方法去除其中的大分子木质素,利用Zeta电位和粒径检测、高效液相色谱法、紫外光谱法等技术分析絮凝处理前后预处理液的成分变化,并对其去除机理进行深入研究。结果表明:当PAC用量为4.00%质量分数时,反应体系Zeta电位为0,此时胶体稳定性最差,可获得较大的木质素沉淀量;当预处理液的pH接近3.00时,刚好达到等电点,体系中正负电荷中和不稳定,胶体颗粒粒径最大,出现明显絮凝沉淀;随着pH的升高,PAC对木质素的去除效果仍有明显增强,综合所有因素可知,在pH为10.00、PAC用量为2.00%质量分数时,处理体系对木质素的絮凝表现出良好的选择性,木质素的选择性去除率可达86.05%。由此可知,PAC主要是通过静电和桥联双重作用改善预处理液的胶体稳定性,使预处理液中的木质素大分子优先沉淀,体现出良好的选择性,是一种非常有潜力的预处理液纯化方法,值得进一步探究和优化。In recent years,with the concept of biomass refining proposed,the efficient utilization of biomass has been highly valued.In order to realize the efficient separation of biomass resources and promote their high-value utilization,raw materials need to be pretreated.Pretreatment is a key step in the transformation of biomass resources.The process can alter the chemical composition structure and distribution in plant cell walls,thereby reducing the recalcitrance of biomass and enhancing the effective dissolution of sugar to promote its high-value utilization.However,the composition of the pretreatment liquid is relatively complicated,and the lignin,formic acid,acetic acid,furfural and hydroxymethyl furfural contained therein are not conducive to the efficient utilization of sugars,so the pretreatment liquid needs to be further separated and purified.With advantages of high annual yield,abundant,and easy-to-harvest,eucalyptus is one of the fast-growing tree species planted artificially in China.In this research,the waste liquid of eucalyptus wood pretreated with MgCl_(2) was used as the object,and the macromolecular lignin was separated and removed by the method of polyaluminum chloride(PAC)flocculation.Zeta potential and particle size detection,high performance liquid chromatography(HPLC)and ultraviolet spectroscopy were used to analyze the composition changes of the pretreatment liquid before and after flocculation,and the removal mechanism was further discussed.The results showed that the reaction system had a Zeta potential of 0 when the amount of PAC was 4.00%(wt%).At this time,the colloidal stability was the worst,and a larger lignin precipitation can be obtained.When the pH value of the pretreatment liquid was close to 3.00,it just reached the isoelectric at this point,the positive and negative charge neutralization in the system was unstable,the colloidal particle size was the largest,and there was obvious flocculation and precipitation.With the increase of pH value,the removal effect of PAC on the lignin was

关 键 词：预处理液 半纤维素 纯化 低聚糖 木质素 

分 类 号：TQ352[化学工程]