葡萄糖與離子液體怎樣進行分離?
來源：http://www.nttdr.com 日期：2019-06-26 發布人：admin
纖維素類生物質轉化為水溶性糖的研討已惹起國內外研討者的普遍專注。但由于纖維素大分子間存在大量的氫鍵，使得纖維素的性質很穩定。它不溶于水，無復原性，在常溫下不發作水解，在高溫下水解也很慢。傳統的纖維素轉化是在生物酶或無機酸水溶液中停止，存在許多不利的要素，如酸水解法腐蝕性強，污染環境，而且在酸性條件下產物容易二次水解，反響不易控制。
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.
酶催化作用存在纖維素酶催化活性低、反復應用率差， 從而招致消費本錢過高的問題。因而，尋覓一種過程綠色化、且能高效轉化纖維素的環境友好工藝已成為當前合理應用生物質能的主要途徑。與傳統的有機溶劑相比，離子液體具有許多不可比較的優點 如蒸氣壓低、不揮發、不可燃、熱穩定性好、液態溫度范圍寬、溶解才能強等特性，并且可經過構造的改動調理其本身性質。
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.
這些特性使離子液體展示出共同的物理化學性質和功用， 成為目前纖維素轉化的一類新型綠色溶劑。目前，曾經有很多研討證明纖維素在離子液體中能高效率的轉化為葡萄糖等水溶性糖。但是，由于葡萄糖與離子液體的別離艱難，使得纖維素在離子液體中的轉化不斷停滯在實驗室階段，嚴重限制其工業化進程。葡萄糖和離子液體都是難揮發性物質，所以普通的蒸餾辦法無法將其別離。
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， 離子液體的溶解才能較強，要找到一種能從離子液體中萃取出葡萄糖的萃取劑也很艱難。 所以，要到達別離葡萄糖和離子液體的目的，必需采用一些新型的別離方式。
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.
抗溶劑法應用的是溶質與溶劑及抗溶劑之間作用力的差別。
The application of antisolvent method is the difference of interaction force between solute and solvent and antisolvent.
所選的抗溶劑與溶劑完整互溶，而與溶質不互溶或微溶。當抗溶劑參加到溶質與溶劑的混合體系中時，由于抗溶劑與溶劑的作用力比溶質與溶劑的作用力強，使溶質在溶劑中的溶解度疾速降低，構成溶質的過飽和溶液，從而使溶質結晶析出。到目前為止，抗溶劑法在葡萄糖與離子液體別離方面的應用還未見報道。 我們將抗溶劑技術應用在從離子液體中回收糖，完成了糖與離子液體的有效別離的辦法。
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.