催化中国, 中国催化分享 http://blog.sciencenet.cn/u/catachina 化学家(www.chemj.cn)

博文

离子液体——Ionic liquids

已有 8911 次阅读 2007-12-17 19:48 |个人分类:科研点滴启发

Instant insight: Ionic liquids - instantly on site

Chemistry World
17 December 2007


Natalia Plechkova and Kenneth Seddon at the Queen's University Ionic Liquids (QUILL) Research Centre, Belfast, examine how ionic liquids are being applied in the real world


Ionic liquids are liquids composed solely of ions, in contrast to conventional solvents comprised of covalent molecules. Their properties mean they are intrinsically excellent candidates for industrial applications compared to volatile organic solvents. Organic solvents have been known for several centuries, and therefore occupy most of the solvent market in industry. If the properties of ionic liquids and organic solvents are to be compared, however, it could be anticipated that industry may be a natural environment for ionic liquids. At the current level of development, ionic liquids can nicely complement, and even sometimes work better than, organic solvents in a number of industrial processes. This statement should not diminish the fact that ionic liquids have plenty of academic applications.

A chemical plant and the BASIL jet stream reactor

The field of ionic liquids is growing at a rate that was unpredictable even five years ago - there were over 2000 papers published in 2006 - and the range of commercial applications is quite staggering; not just in the number, but in their wide diversity, arising from close cooperation between academia and industry. Of all the industrial giants, BASF have done the most publicly to implement ionic liquid technology. They possess the largest patent portfolio, have the broadest range of applications, and work openly with leading academics. Currently, the most successful example of an industrial process using ionic liquid technology is the BASILTM (biphasic acid scavenging utilising ionic liquids) process. This first commercial publicly-announced process was introduced to the BASF site in Ludwigshafen, Germany, in 2002. The BASILTM process is used for the production of the generic photoinitiator precursor alkoxyphenylphosphines.


"Ionic liquids are intrinsically excellent candidates for industrial applications"
In the original process, triethylamine was used to scavenge the acid that was formed in the course of the reaction, but this made the reaction mixture difficult to handle as the waste by-product, trimethylammonium chloride, formed a dense insoluble paste. Replacing triethylamine with 1-methylimidazole results in the formation of 1-methylimidazolium chloride, an ionic liquid that separates out of the reaction mixture as a discrete phase. The new process uses a much smaller reactor than the initial process; the space-time yield increased from 8 g m-3 h-1 to 690 000 kg m-3 h-1, and the yield from 50% to 98%. 1-Methylimidazole is recycled, via base decomposition of 1-H-3-methylimidazolium chloride, in a proprietary process. The reaction is now carried out at a multi-ton scale, proving that handling large quantities of ionic liquids is practical. BASF have also developed process for breaking azeotropes, dissolving and processing cellulose, replacing phosgene as a chlorinating agent with hydrochloric acid, and aluminium plating. And there are at least fifteen other companies with processes either operating or at pilot. Degussa, for example, have a hydrosilylation process, have developed ionic liquids as paint additives and have a programme for lithium ion batteries.

"The most successful example of an industrial process using ionic liquid technology is the BASIL process"
The concepts and paradigms of ionic liquids are new and still not fully accepted in the wider community: it is hard for conservative scientists to throw away thousands of years of concepts grown from the fertile ground (ocean?) of molecular solvents, and if chemists are conservative, then chemical engineers are even more so. But there is always a flipside or mirror image, and there are now many laboratories all over the world (and the growth in China is spectacular) that work with ionic liquids.

Read more in Natalia Plechkova and Ken Seddon's critical review 'Applications of ionic liquids in the chemical industry' in January's  Chemical Society Reviews.

Link to journal article

Applications of ionic liquids in the chemical industry
Natalia V. Plechkova and Kenneth R. Seddon, Chem. Soc. Rev., 2008
DOI: 10.1039/b006677j


Related Links

Link icon Queen's University Ionic Liquid Laboratories
Read more about Seddon's work here

External links will open in a new browser window


Also of interest

Inorganic materials from ionic liquids
Andreas Taubert and Zhonghao Li, Dalton Trans., 2007, 723
DOI: 10.1039/b616593a

The E Factor: fifteen years on
Roger A. Sheldon, Green Chem., 2007, 9, 1273
DOI: 10.1039/b713736m


Mild green ionic liquids

Washing with eutectic solvents cleans up biodiesel - and produces glycerol.

The third age of ionic liquids?

Scientists in the US and Poland have shown that ionic liquids could have significant biological applications in drug delivery.

Testing the toxicity of ionic liquids

Ionic liquids have often been touted as the ultimate green solvent, but just how green is green?





https://blog.sciencenet.cn/blog-3913-12819.html

上一篇:【名家论坛】生物柴油的价格
下一篇:ACB文章接受,谈谈过程、经验、想法
收藏 IP: .*| 热度|

1 李丽

发表评论 评论 (1 个评论)

数据加载中...
扫一扫,分享此博文

Archiver|手机版|科学网 ( 京ICP备07017567号-12 )

GMT+8, 2024-3-29 16:41

Powered by ScienceNet.cn

Copyright © 2007- 中国科学报社

返回顶部