絮凝法分离稻草秸秆预处理碱液中的木质素  

Flocculation separation of lignin in the rice straw pretreatment lye

作　　者：方强[1] 王淮[2] 朱慧霞[2] 邓胜松[2] 何洪波[2] 姚日生[2] 

机构地区：[1]合肥工业大学化学与化工学院,安徽合肥230009 [2]合肥工业大学医学工程学院,安徽合肥230009

出　　处：《化工进展》2015年第11期4096-4102,4107,共8页Chemical Industry and Engineering Progress

基　　金：国家863计划(2014AA021902);安徽省教育厅自然科学研究项目(2013AJZR0044);安徽省科技攻关计划(1301032144)项目

摘　　要：农作物秸秆作为最具有代表性的木质纤维素资源,预处理是影响其组分分离与应用的关键因素。本文提出了基于SO3原位微热爆结合碱洗的秸秆预处理新方法,可高效实现秸秆三大主要组分的分离。为实现预处理碱液中的木质素回收,并将分离后的碱液回收套用,借鉴离子交换树脂中金属离子交换的思路,探讨了采用离子交换形成絮凝沉淀的方式对碱液中木质素加以分离。通过金属离子筛选,采用CaCl2对碱液中木质素进行分离,分别探讨了CaCl2添加量、絮凝时间、絮凝温度、絮凝转速及碱液p H值对絮凝物中木质素含量的影响。研究表明,原碱液透析后可大大提高CaCl2对碱液中木质素的絮凝能力,同时对絮凝分离产物中木质素得率进行考察,得出1%的CaCl2添加量、絮凝6h、50℃以及p H值11分别为各自的最适条件,在该条件下絮凝分离产物中木质素得率达到61.08%。通过絮凝物的组分质量检测以及红外谱图、XPS的分析,能够确定絮凝物中木质素的存在。在此基础上,初步分析了Ca2+絮凝分离碱液中木质素的机理。Straw is a representative lignocellulose resource,and its pretreatment is a key factor in its separation and the application of its constituents. Based on SO3micro-thermal explosion and alkali treatment,an efficient separation of three major constituents of rice straw was achieved. In this paper, in order to recover the lignin and recycle the lye,the flocculation-separation through ion exchange of lignin was explored by learning from ion exchange separation. With the screening of metal ion,CaCl2 was chosen to separate lignin in the lye. Also,the effects of different factors,such as adding amount of CaCl2,flocculation time,temperature,rotating speed and pH,on lignin isolated yield were explored. The result shows CaCl2flocculation of lignin can be greatly improved by dialysis treatment. Meanwhile,the yield of lignin in the flocculation was investigated. The optimal condition is as follows：1% of CaCl2 adding amount,6h,50℃,150r/min and pH 11. Under above condition,lignin isolated yield could reach 61.08%. With the detection of flocculate,the analysis of IR and XPS,the existence of lignin in the flocculate was determined. Further,the mechanism of flocculation-separation of lignin by Ca2＋ in the lye was analyzed preliminarily.

关 键 词：秸秆 絮凝分离 预处理碱液 木质素 

分 类 号：O636.2[理学—高分子化学]