Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603, Kuala Lumpur, Malaysia.
Biotechnol Biofuels. 2012 Sep 7;5(1):67. doi: 10.1186/1754-6834-5-67.
In the present study, three ionic liquids, namely 1-butyl-3-methylimidazolium chloride ([BMIM]Cl), 1-ethyl-3-methylimidazolium acetate ([EMIM]OAc), and 1-ethyl-3-methylimidazolium diethyl phosphate ([EMIM]DEP), were used to partially dissolve rice husk, after which the cellulose were regenerated by the addition of water. The aim of the investigation is to examine the implications of the ionic liquid pretreatments on rice husk composition and structure.
From the attenuated total reflectance Fourier transform-infrared (ATR FT-IR) spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM) results, the regenerated cellulose were more amorphous, less crystalline, and possessed higher structural disruption compared with untreated rice husk. The major component of regenerated cellulose from [BMIM]Cl and [EMIM]DEP pretreatments was cellulose-rich material, while cellulose regenerated from [EMIM]OAc was a matrix of cellulose and lignin. Cellulose regenerated from ionic pretreatments could be saccharified via enzymatic hydrolysis, and resulted in relatively high reducing sugars yields, whereas enzymatic hydrolysis of untreated rice husk did not yield reducing sugars. Rice husk residues generated from the ionic liquid pretreatments had similar chemical composition and amorphousity to that of untreated rice husk, but with varying extent of surface disruption and swelling.
The structural architecture of the regenerated cellulose and rice husk residues showed that they could be used for subsequent fermentation or derivation of cellulosic compounds. Therefore, ionic liquid pretreatment is an alternative in the pretreatment of lignocellulosic biomass in addition to the conventional chemical pretreatments.
在本研究中，使用了三种离子液体，即 1-丁基-3-甲基咪唑氯化物([BMIM]Cl)、1-乙基-3-甲基咪唑乙酸盐([EMIM]OAc)和 1-乙基-3-甲基咪唑二乙基磷酸盐([EMIM]DEP)，部分溶解稻壳，然后通过加水再生纤维素。研究的目的是研究离子液体预处理对稻壳组成和结构的影响。
从衰减全反射傅里叶变换红外光谱(ATR FT-IR)、X 射线衍射(XRD)和扫描电子显微镜(SEM)结果来看，与未经处理的稻壳相比，再生纤维素的结晶度更低，结构破坏程度更高。[BMIM]Cl 和[EMIM]DEP 预处理再生纤维素的主要成分是富含纤维素的物质，而[EMIM]OAc 再生的纤维素是纤维素和木质素的基质。离子预处理再生的纤维素可通过酶水解转化为还原糖，产率较高，而未经处理的稻壳的酶水解则不产生还原糖。离子液体预处理产生的稻壳残渣的化学组成和无定形度与未经处理的稻壳相似，但表面破坏和溶胀程度不同。
再生纤维素和稻壳残渣的结构结构表明，它们可用于后续发酵或纤维素化合物的衍生。因此，离子液体预处理是除传统化学预处理外，木质纤维素生物质预处理的另一种选择。
