(43c) Novel Pyridinium-Based Ionic Liquids for Efficient and Reversible Capture of SO2 | AIChE

(43c) Novel Pyridinium-Based Ionic Liquids for Efficient and Reversible Capture of SO2

Authors 

Zeng, S. - Presenter, Chinese Academy of Sciences
Gao, H. - Presenter, Institute of Process Engineering, Chinese Academy of Sciences
Zhang, X. - Presenter, Institute of Process Engineering, Chinese Academy of Sciences
Zhang, S. - Presenter, Institute of Process Engineering, Chinese Academy of Sciences

Novel
Pyridinium-based Ionic Liquids
for Efficient
and Reversible Capture of SO2

Shaojuan
Zeng a, b, Hongshuai Gao
a,Xiangping
Zhang a,*,
Suojiang Zhang a,*

aBeijing
Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of
Multiphase Complex System, Institute
of Process Engineering, Chinese Academy of Sciences,
100190, Beijing,
China

bCollege
of Chemical and Engineering, University of Chinese Academy of Sciences,
100049,  Beijing
, China

*Corresponding author: sjzhang@ipe.ac.cn; xpzhang@ipe.ac.cn

 The reduction of SO2 emission from flue gases has become one of the
most urgent environmental issues for a sustainable society. Although some
traditional methods for flue gas desulfurization (FGD) have been commercialized, there are still some inherent drawbacks. For example, limestone
scrubbing produces
a large amount of solid wastes and waste water, which may result in secondary
pollution to the environment1. Therefore, the development of a proper absorbent
for efficient and reversible capture of SO2 is of critical
importance.

 Recently,
ionic liquids (ILs) have drawn much attention as potential absorbents for SO2 capture due to their unique
properties2. To our knowledge, very few studies on pyridinium-based ILs
for SO2 removal
were reported, although they
have higher thermal stability, lower cost and higher biodegradability than imidazolium-based ILs3. In this work, the
interaction between various cations, e.g. different alkyl chain length and functionalized substituent
groups on the pyridinium ring, and anions of ILs and SO2
was firstly studied by Quantum
Chemical calculation and Molecular Dynamic simulation. Based on the calculation results,
a series of pyridinium-based
ILs were
designed and synthesized for
SO2 capture. The results indicated that the gravimetric capacity of SO2
decreases with increase of the length of alkyl chain. Comparing with cation of
IL, anion plays a dominant role in SO2 absorption, which is consistent with the calculation resluts.
Among the investigted anions, the conventional IL with [SCN] shows the highest SO2 capacity, and good selectivity for SO2
to other gases and excellent reversibility4. Meanwhile, the incorporation of functionalized substituent
groups on the
cation, such as tertiary amino group, ether group and
nitrile group plays
a key role in improving SO2
capture, which exhibited much
better absorption performances of SO2 than the conventional IL with [SCN]. This work will provide some useful information to design more competitive absorbents for SO2
capture.

REFERENCES

1.         X.
X. Ma, T. Kaneko, T. Tashimo, T. Yoshida and K. Kato, Chem Eng Sci,
2000, 55, 4643-4652.

2.         S.
Y. Hong, J. Im, J. Palgunadi, S. D. Lee, J. S. Lee, H. S. Kim, M. Cheong and
K.-D. Jung, Energy Environ Sci, 2011, 4, 1802-1806.

3.         K.
M. Docherty, J. K. Dixon and C. F. Kulpa Jr, Biodegradation, 2006, 18,
481-493.

4.         S.
Zeng, H. Gao, X. Zhang, H. Dong, X. Zhang and S. Zhang, Chem Eng J,
2014, 251, 248-256.