(669a) Applications of Ionic Liquids in Green Process Engineering

A significant amount of researches on ionic liquids (ILs) have been prompted from fundamentals to applications due to their unique characteristics, such as nonvolatility, excellent catalytic and dissolvability properties. For process engineering, the applications of ILs may improve reaction rate and selectivity, and reduce the cost of product separation, and therefore lead to great innovations in process technologies. We would like to use this opportunity to bring to the forefront the many exciting challenges and opportunities in this field.

However, there are still a number of challenges to be tackled for application of ILs in large scale. In order to design task-specific ILs and develop innovative green processes, it is indispensable to understand the nature of ILs from the multiscale viewpoints. Quantum mechanics (QM), molecular dynamics (MD) and computational fluid dynamics (CFD) have been performed to depict the multiscale structures and properties of ILs.

Based on the fundamental understanding in the structures, properties and process scale-up of ILs, several innovative green processes using ILs as catalysts or solvents, such as cleaner process of Methyl methacrylate (MMA), cleaner process of ethylene glycol and de-acid process from oils, were developed.

Here we firstly show green process for producing methyl methacrylate (MMA), in which ionic liquids as the solvents or catalysts lead to great innovations in the absorption and reaction processes. A reaction-separation coupled one-step technique using ILs as medium is developed for MAL to MMA without methacrylic acid (MAA) step of the existing processes. Comparing the traditional hydrocyanic acid process, the new process achieved both the economic and environmental benefits. Another example is using ILs as catalyst for producing ethylene glycol instead of the traditional direct hydration of ethylene oxide, the new process could save large quantity of energy and significantly reduce wastewater discharge amount. A new naphthenic acid extraction process based on the principle of ?switchable ionic liquid? is also developed. Because of the difference of the polarity between ionic liquid and lube base oil, naphthenic acid could be removed and recovered from lube base oil. This technique will be a new high atomic economy process, no pollution and ?zero? emission.

Acknowledgments

The authors sincerely appreciate financial supports from National Scientific Funding of China for Distinguished Young Scholar (20625618 and 20806083), National Basic Research Program of China (973 Program, 2009CB219902).