Examination of degree of cross-linking for cellulose precursors pretreated with acid/hot water at low temperature
Examination of degree of cross-linking for cellulose precursors pretreated with acid/hot water at low temperature
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DOI：
10.1021/ie800080u
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发表时间：
2008-08-20
影响因子：
4.2
通讯作者：
Mae, Kazuhiro
中科院分区：
文献类型：
--
作者：
Chaiwat, Weerawut;Hasegawa, Isao;Mae, Kazuhiro
在低温（200-260 ℃）下用酸和热水对纤维素进行预处理，以通过改变前体结构来控制热解产物。酸预处理使纤维素形成部分交联的疏松结构，经快速热解产生大量的焦油，焦油中含有左旋葡聚糖和高分子量组分。相反，热水处理通过赋予纤维素前体无规和高度交联的结构而引起焦油形成的抑制。提出了一个新的参数指标，即预处理前体的交联度，X-0，它是基于从预处理样品的酸水解产生的葡萄糖和寡糖的产率，来分析前体结构。由于交联度随着预处理条件的严重性而增加，预处理样品中的OH基团的数量减少。通过对固体前驱物的分析，提出了一个简单的结构模型，以正确估计热解产物的分布。估算值与闪速热解实验得到的产物产率一致。
Pretreatment of cellulose with acid and hot water at low temperature (200-260 degrees C) was performed to control the pyrolysis products by changing the precursor structure. Acid pretreatment changed cellulose into a partly cross-linked and loose structure, which resulted in a large amount of tar consisting of levoglucosan and high-molecular weight components by flash pyrolysis. On the contrary, hot water treatment caused the suppression of tar formation by imparting a random and highly cross-linked structure to the cellulose precursor. A new parameter index, referred to as the degree of cross-linking for pretreated precursors, X-0, which is based on glucose and oligosaccharide yields produced from acid hydrolysis of pretreated samples, was proposed to analyze the precursor structure. As the degree of cross-linking increased with the severity of the pretreatment conditions, the number of OH groups in the pretreated samples decreased. Through analysis of the solid precursors using this index, a simple structural model was proposed to properly estimate the distribution of the pyrolysis products. The estimated values were in agreement with the product yields experimentally obtained by flash pyrolysis.