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Absorption of SO2 in hollow fiber membrane contactors using various aqueous absorbents
Desalination 200 (2006) 604–605
Absorption of SO2 in hollow fiber membrane contactors using various aqueous absorbents Hyung-Keun Leea*, Hang-Dae Joa, Won-Kil Choia, Hyun-Hee Parka, Chun-Won Lima, Yong-Taek Leeb a
Clean Energy Research Department, Korea Institute of Energy Research, Daejeon, S. Korea email: [email protected] b Department of Chemical Engineering, Chung-Nam National University, Daejeon, S. Korea Received 25 October 2005; accepted 6 March 2006
1. Introduction
2. Results and discussion
Sulfur oxides (SOx) are the major air pollutant which is emitted from the stationary sources such as power plants, incinerators and combustors [1]. The most effective technology for the SO2 removal is flue gas desulphurization (FGD) process. Commercial processes for the removal of SO2 use limestone slurry as a scrubbing solution. These wet FGD processes have been widely accepted because of lower cost, simple operation and higher SOx removal efficiency compared to other processes [2]. Compared to this conventional FGD process, separation technology using membrane contactors is attracting much attention because of its high mass transfer coefficient and compact size [3]. In this study, SO2 removal efficiencies and mass transfer coefficients in the hollow fiber (HF) membrane contactors were obtained at various gas and liquid flows. The separation efficiency of NaOH was compared with other aqueous absorbent such as Na2CO3, Na2SO3 and NaHCO3 .
The experimental apparatus for the measurements of the SO2 removal efficiencies and mass transfer coefficients through HF membrane contactors is shown in Fig. 1. The membranes used in this study were supplied from the PHILOS
*Corresponding author.
Fig. 1. Schematic diagram of experimental apparatus.
Presented at EUROMEMBRANE 2006, 24–28 September 2006, Giardini Naxos, Italy. 0011-9164/06/$– See front matter © 2006 Published by Elsevier B.V. doi:10.1016/j.desal.2006.03.435
H.-K. Lee et al. / Desalination 200 (2006) 604–605 100
100
SO2 removal efficiency (%)
SO2 removal efficiency (%)
120
80 60 40 Water 0.02M NaOH 0.2M NaOH
20 0
0
10
20 30 40 50 Liquid flow rate (cc/min)
60
80
60
40 0.02 M NaOH 0.02 M Na2CO3 0.02 M Na2SO3 0.02 M NaHCO3
20
70
0
Fig. 2. Effect of absorbent concentrations on SO2 removal efficiency of KM2 module.
Co. (Korea) and Liqui-cel. To compare the performances of HFs, standardized modules of 0.01 m diameter, 0.015 m length with different number of HFs were manufactured. Fig. 2 shows the effect of absorbent concentrations on SO2 removal efficiency of polysulfone KM2 module, with an outside diameter of 0.06 m, a length of 0.294 m. The outside and inside diameter of HF of KM2 was 400 mm, 200 mm, respectively. The gas flow rate was controlled at 2 L/min and inlet SO2 concentration was 400 ppm. 100
SO2 removal efficiency (%)
605
80
0
2
4
6 8 10 12 Liquid flow rate (cc/min)
14
16
Fig. 4. Effect of absorbents on SO2 removal efficiency.
SO2 removal efficiency was increased with the liquid flow rate and concentration of absorbents. Effect of modules on SO2 removal efficiency in 2 M NaOH was shown in Fig. 3. Polypropylene HF of KM1 module was supplied from Liqui-cel and others are supplied from PHILOS Co. The pore sizes of KM1, KM3 and KM4 were 0.003 mm, 0.05 mm, 0.1 mm, respectively. SO2 removal efficiency decreases with increasing the gas flow rate but increases with the pore size. Fig. 4 shows the effects of various absorbents on SO2 removal efficiency of KM4 module whose number of HFs was 40. The gas flow rate was held constant at 2 L/min and input SO2 concentration was 2000 ppm. The performance of 0.02 M Na2CO3 was shown the highest SO2 removal efficiency among the absorbents.
60
References 40
[1]
20
0
KM1-200 KM3-200 KM4-200 0
4
8 12 Gas flow rate (L/min)
16
[2] 20
Fig. 3. Comparison of hollow fiber membrane modules on SO2 removal efficiency in 2 M NaOH.
[3]
Z. Qi and E.L. Cussler, Microporous hollow fibers for gas absorption: I. Mass transfer in the liquid, J. Membr. Sci., 23(3) (1985) 321–332. S. Karoor and K.K. Sirkar, Gas absorption studies in Microporous hollow fiber membrane modules, Ind. Eng. Chem. Res., 32(4) (1993) 674–684. S. Nii and H. Takeuchi, Removal of CO2 and/or SO2 from gas streams by a membrane absorption method, Gas Separ. Purif., 8(2) (1994) 107–114.
Absorption of SO2 in hollow fiber membrane contactors using various aqueous absorbents Hyung-Keun Leea*, Hang-Dae Joa, Won-Kil Choia, Hyun-Hee Parka, Chun-Won Lima, Yong-Taek Leeb a
Clean Energy Research Department, Korea Institute of Energy Research, Daejeon, S. Korea email: [email protected] b Department of Chemical Engineering, Chung-Nam National University, Daejeon, S. Korea Received 25 October 2005; accepted 6 March 2006
1. Introduction
2. Results and discussion
Sulfur oxides (SOx) are the major air pollutant which is emitted from the stationary sources such as power plants, incinerators and combustors [1]. The most effective technology for the SO2 removal is flue gas desulphurization (FGD) process. Commercial processes for the removal of SO2 use limestone slurry as a scrubbing solution. These wet FGD processes have been widely accepted because of lower cost, simple operation and higher SOx removal efficiency compared to other processes [2]. Compared to this conventional FGD process, separation technology using membrane contactors is attracting much attention because of its high mass transfer coefficient and compact size [3]. In this study, SO2 removal efficiencies and mass transfer coefficients in the hollow fiber (HF) membrane contactors were obtained at various gas and liquid flows. The separation efficiency of NaOH was compared with other aqueous absorbent such as Na2CO3, Na2SO3 and NaHCO3 .
The experimental apparatus for the measurements of the SO2 removal efficiencies and mass transfer coefficients through HF membrane contactors is shown in Fig. 1. The membranes used in this study were supplied from the PHILOS
*Corresponding author.
Fig. 1. Schematic diagram of experimental apparatus.
Presented at EUROMEMBRANE 2006, 24–28 September 2006, Giardini Naxos, Italy. 0011-9164/06/$– See front matter © 2006 Published by Elsevier B.V. doi:10.1016/j.desal.2006.03.435
H.-K. Lee et al. / Desalination 200 (2006) 604–605 100
100
SO2 removal efficiency (%)
SO2 removal efficiency (%)
120
80 60 40 Water 0.02M NaOH 0.2M NaOH
20 0
0
10
20 30 40 50 Liquid flow rate (cc/min)
60
80
60
40 0.02 M NaOH 0.02 M Na2CO3 0.02 M Na2SO3 0.02 M NaHCO3
20
70
0
Fig. 2. Effect of absorbent concentrations on SO2 removal efficiency of KM2 module.
Co. (Korea) and Liqui-cel. To compare the performances of HFs, standardized modules of 0.01 m diameter, 0.015 m length with different number of HFs were manufactured. Fig. 2 shows the effect of absorbent concentrations on SO2 removal efficiency of polysulfone KM2 module, with an outside diameter of 0.06 m, a length of 0.294 m. The outside and inside diameter of HF of KM2 was 400 mm, 200 mm, respectively. The gas flow rate was controlled at 2 L/min and inlet SO2 concentration was 400 ppm. 100
SO2 removal efficiency (%)
605
80
0
2
4
6 8 10 12 Liquid flow rate (cc/min)
14
16
Fig. 4. Effect of absorbents on SO2 removal efficiency.
SO2 removal efficiency was increased with the liquid flow rate and concentration of absorbents. Effect of modules on SO2 removal efficiency in 2 M NaOH was shown in Fig. 3. Polypropylene HF of KM1 module was supplied from Liqui-cel and others are supplied from PHILOS Co. The pore sizes of KM1, KM3 and KM4 were 0.003 mm, 0.05 mm, 0.1 mm, respectively. SO2 removal efficiency decreases with increasing the gas flow rate but increases with the pore size. Fig. 4 shows the effects of various absorbents on SO2 removal efficiency of KM4 module whose number of HFs was 40. The gas flow rate was held constant at 2 L/min and input SO2 concentration was 2000 ppm. The performance of 0.02 M Na2CO3 was shown the highest SO2 removal efficiency among the absorbents.
60
References 40
[1]
20
0
KM1-200 KM3-200 KM4-200 0
4
8 12 Gas flow rate (L/min)
16
[2] 20
Fig. 3. Comparison of hollow fiber membrane modules on SO2 removal efficiency in 2 M NaOH.
[3]
Z. Qi and E.L. Cussler, Microporous hollow fibers for gas absorption: I. Mass transfer in the liquid, J. Membr. Sci., 23(3) (1985) 321–332. S. Karoor and K.K. Sirkar, Gas absorption studies in Microporous hollow fiber membrane modules, Ind. Eng. Chem. Res., 32(4) (1993) 674–684. S. Nii and H. Takeuchi, Removal of CO2 and/or SO2 from gas streams by a membrane absorption method, Gas Separ. Purif., 8(2) (1994) 107–114.