(501f) Conversion of Residual Ethylene Oxide in the Ionic Liquid Catalyzed CO2 Cycloaddition Process

Conversion of residual ethylene
oxide in the ionic liquid catalyzed CO₂ cycloaddition process

Jian Sun, Weiguo Cheng, Jinquan Wang, Junping Zhang
and Suojiang Zhang

Institute of Process Engineering, Chinese
Academy of Sciences,100190, Beijing, PR China

*Contact information: jsun@home.ipe.ac.cn

Recently, the synthesis of
cyclic carbonates via cycloaddition of CO₂ to epoxides is much attractive
not only because of its efficiency in CO₂ conversion, but also becuase
of its widely derivative high-value chemicals.^[1] Although a number
of efficient catalysts including ionic liquids (ILs) have been developed, ^[2]
attention on the trace residual epoxide in the reaction system, especially in gas
phase, is rarely covered, which could cause a potential explosion of epoxide
when unreacted CO₂ is compressed for recyle. As a continous work for
CO₂ conversion,^[3] herein, studies on the conversion of
residual trace epoxide (0.2 wt%) in an IL catalyzed CO₂ cycloaddition
process to produce ethylene carbonate (EC) were carried out. The effect parameters
including pressure, temperature, time and solvents (e.g. H₂O, EC+ethylene
glycol+H₂O, BmimCl, BmimPF₆, BmimBF₄, etc) were
systematically screened, and a >99.9% conversion of EO could be realized by
reduding the partial pressure of EO in the system. The results indicated that a
vapor-liquid equilibriuma of EO in the reaction system has a more important effect
on EO elimination rather than reaction time and temperature.

Refferences

[1]  B.
Schaffner, F. Schaffner, S.P. Verevkin and A. Borner, Chem. Rev., 2010, 110,
4554.

[2]  a)
J. M. Zhang, J. Sun, X. C. Zhang, Y. S. Zhao, S. J. Zhang. Greenhouse Gas Sci Technol.,
2011, 2:142-159; b) M. North, R. Pasquale, C. Young, Green Chem., 2010, 12,
1514.

[3]  a)
J.Q. Wang, J. Sun, W.G Cheng, S.J. Zhang. Phys. Chem. Chem. Phys., 2012, 14,
11021; b) J. Sun, L. J. Han, W. G. Cheng , J. Q. Wang, X. P. Zhang, S. J.
Zhang. ChemSusChem, 2011, 4: 502; c) J. Sun, J.Q. Wang, W. G. Cheng,
J. X. Zhang, X. H. Li, S. J. Zhang, Y. B. She. Green Chem., 2012, 14:
654; d) J. Sun, W. G. Cheng, W. Fan, Y. H. Wang, Z. Y. Meng, S. J. Zhang. Catal.
Today, 2009, 148: 361.

Acknowledgments

This
work was supported by National
Basic Research
Program of China (2009CB219901), and National Science Fund of China (21006117).