葡萄糖与离子液体怎样进行分离?
来源：http://www.jnjdbc.com 日期：2019-06-26 发布人：admin
纤维素类生物质转化为水溶性糖的研讨已惹起国内外研讨者的普遍专注。但由于纤维素大分子间存在大量的氢键，使得纤维素的性质很稳定。它不溶于水，无复原性，在常温下不发作水解，在高温下水解也很慢。传统的纤维素转化是在生物酶或无机酸水溶液中停止，存在许多不利的要素，如酸水解法腐蚀性强，污染环境，而且在酸性条件下产物容易二次水解，反响不易控制。
The conversion of cellulosic biomass into water-soluble sugars has attracted the attention of researchers at home and abroad. However, due to the existence of a large number of hydrogen bonds between cellulose macromolecules, the properties of cellulose are very stable. It is insoluble in water, has no recovery, does not occur hydrolysis at room temperature, hydrolysis is slow at high temperature. Traditional cellulose conversion stops in the aqueous solution of biological enzymes or inorganic acids. There are many unfavorable factors, such as strong corrosiveness of acid hydrolysis, environmental pollution, and easy secondary hydrolysis of products under acidic conditions, and the reaction is not easy to control.
酶催化作用存在纤维素酶催化活性低、反复应用率差， 从而招致消费本钱过高的问题。因而，寻觅一种过程绿色化、且能转化纤维素的环境友好工艺已成为当前合理应用生物质能的主要途径。与传统的有机溶剂相比，离子液体具有许多不可比较的优点 如蒸气压低、不挥发、不可燃、热稳定性好、液态温度范围宽、溶解才能强等特性，并且可经过构造的改动调理其本身性质。
Enzyme catalysis has the problems of low catalytic activity and poor repetitive application rate of cellulase, which leads to high consumption cost. Therefore, searching for an environmentally friendly process which is green and efficient for cellulose conversion has become the main way for rational application of biomass energy. Compared with traditional organic solvents, ionic liquids have many incomparable advantages, such as low vapor pressure, non-volatile, non-flammable, good thermal stability, wide liquid temperature range, strong dissolution ability, and can adjust their own properties through structural changes.
这些特性使离子液体展示出共同的物理化学性质和功用， 成为目前纤维素转化的一类新型绿色溶剂。目前，曾经有很多研讨证明纤维素在离子液体中能率的转化为葡萄糖等水溶性糖。但是，由于葡萄糖与离子液体的别离艰难，使得纤维素在离子液体中的转化不断停滞在实验室阶段，严重限制其工业化进程。葡萄糖和离子液体都是难挥发性物质，所以普通的蒸馏办法无法将其别离。
These characteristics make ionic liquids exhibit common physical and chemical properties and functions, and become a new type of green solvent for cellulose conversion. At present, many studies have proved that cellulose can be efficiently converted into water-soluble sugars such as glucose in ionic liquids. However, due to the difficulty of separating glucose from ionic liquids, the conversion of cellulose in ionic liquids has been stagnating in the laboratory stage, which severely restricts its industrialization process. Glucose and ionic liquids are non-volatile substances, so ordinary distillation methods can not separate them.
另外， 离子液体的溶解才能较强，要找到一种能从离子液体中萃取出葡萄糖的萃取剂也很艰难。 所以，要到达别离葡萄糖和离子液体的目的，必需采用一些新型的别离方式。
In addition, ionic liquids can dissolve strongly, and it is difficult to find an extractant that can extract glucose from ionic liquids. Therefore, in order to achieve the purpose of separating glucose from ionic liquids, some new separation methods must be adopted.
抗溶剂法应用的是溶质与溶剂及抗溶剂之间作用力的差别。
The application of antisolvent method is the difference of interaction force between solute and solvent and antisolvent.
所选的抗溶剂与溶剂完整互溶，而与溶质不互溶或微溶。当抗溶剂参加到溶质与溶剂的混合体系中时，由于抗溶剂与溶剂的作用力比溶质与溶剂的作用力强，使溶质在溶剂中的溶解度疾速降低，构成溶质的过饱和溶液，从而使溶质结晶析出。到目前为止，抗溶剂法在葡萄糖与离子液体别离方面的应用还未见报道。 我们将抗溶剂技术应用在从离子液体中回收糖，完成了糖与离子液体的有效别离的办法。
The selected anti-solvent is completely soluble with the solvent, but not with the solute or slightly soluble. When the anti-solvent is added to the mixture of solute and solvent, the solubility of the solute in the solvent decreases rapidly due to the stronger action of the anti-solvent and the solvent than that of the solute and the solvent, thus forming the supersaturated solution of the solute, which leads to the crystallization of the solute. So far, the application of antisolvent method in the separation of glucose from ionic liquids has not been reported. We have applied antisolvent technology to recover sugar from ionic liquids, and completed the effective separation of sugar from ionic liquids.