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Phase Separation Solvent for CO2 Capture
Available online at www.sciencedirect.com
ScienceDirect Energy Procedia 114 (2017) 823 – 826
13th International Conference on Greenhouse Gas Control Technologies, GHGT-13, 14-18 November 2016, Lausanne, Switzerland
Phase Separation Solvent for CO2 Capture Hiroshi Machidaa*, Takehiro Esakia, Kazuki Obaa, Takashi Tomikawaa, Tsuyoshi Yamaguchia, Hirotoshi Horizoea a
Department of Chemical Engineering, Nagoya University
Abstract We developed the new type of CO2 absorption solvent which transforms into two liquids phase with CO2 absorption. CO2 solubility of three types of phase separation solvent were measured and discussed about the hydrophobicity. © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license © 2017 The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of GHGT-13. Peer-review under responsibility of the organizing committee of GHGT-13. Keywords: CO2 capture; phase separation;
1. Introduction Carbon dioxide capture technology has been focused on applicable system for global worming problem. Amine scrubbing system was practically used in recent decades. In this system, most part of CO 2 separation energy is amine regeneration energy. To develop the energy saving system, there have reported several amine structures. Recently, phase separation type CO2 capture solvent has received an attention in recent years [1-8]. We developed the new type of CO2 absorption solvent which transforms into two liquids phase with CO2 absorption. Figure 1 shows CO2 separation process with our developed solvent. Flue gas contacts with solvent in absorption column. After absorption, CO2 dissolved solvent was separated to CO2 rich-phase and CO2 lean-phase. Only CO2 rich-phase was moved to desorption column and solvent was regenerated. Regenerated solvent and CO2 lean-phase was mixed and reused for CO2 absorption. Since CO 2 rich-phase shows high CO2 solubility and low water content, latent heat and sensible heat energy is expected to decrease. In this work, CO2 solubility of three types of phase separation solvent were measured and discussed about the hydrophobicity.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of GHGT-13. doi:10.1016/j.egypro.2017.03.1224
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CO2
Treated gas
Bent
Flow meter
Absorber
Mixer
T
Condenser
Regenerator
CO2
Flue gas N2
Fig. 1 Process flow of phase separation type CO2 capture
Water bath
Stirrer
Fig.2 CO2 solubility measurement apparatus
2. Measurement Fig.2 shows an apparatus of CO2 solubility measurement. Solvent was loaded in the cell and temperature was controlled by a circulation thermostatic bath. CO2 and N2 mixed gas was flowed in the cell at ambient pressure. When the equilibrium reached, composition of liquid phase was analyzed with TOC, GC. If there shows two liquid phases, each phase were analyzed separately. We selected three types of phase separation solvent, EAE+DEGDEE, EAE+DEGDME, MAE+DEGDME. Temperature set to 313 K and pressure set to 1-100 kPa. CO2 solubility = mol-CO2 in lean or rich phase / mol-amine in both phase Table 1 Chemical formula and suppliers of materials Materials 2-(Ethylamino) ethanol
Supplier EAE
Chemical formula
TCI
2-(Methylamino) MAE WAKO ethanol Diethylene DEGDEE TCI Glycol Diethyl Ether Diethylene DEGDME TCI Glycol Dimethyl Ether TCI: Tokyo Chemical Industry CO.,Ltd., WAKO: Wako Pure Chemical Industries, Ltd.
3. Results and discussion Figure 3 shows the picture before and after CO2 absorption for solvent (EAE:DEGDEE:water = 3:6:1 weight base). Before CO2 absorption, solvent showed single liquid phase but after CO 2 absorption, it showed two liquid phases. Figure 4 shows the mechanism of phase separation with CO2 absorption. Carbamate salt which is produced by amine-CO2 reaction cannot dissolve in the ether phase and forms the second liquid phase.
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Before absorption
After absorption CO2
Ether solvent + water
CO2 CO2 R-NH
R-NH
CO2
CO2 lean
R-NH R-NH
Single liquid phase Fig. 3 Picture of phase separation solvent
CO2 rich
R-NH2+ R-NCO2䠉
Two liquid phase
Fig. 4 Mechanism of phase separation solvent
Figure 5 shows the CO2 solubility in phase separation solvent. There showed CO2 rich phase and CO2 lean phase. When EAE was selected for amine (Fig.5a), phase separation pressure of DEGDME is higher than DEGDEE. It caused by carbamate affinity for ether solvent. Since hydrophobicity of DEGDEE may be larger than that of DEGDME because of alkyl chain length, carbamate is smaller affinity for DEGDEE. When DEDME was selected for ether (Fig.5b), phase separation pressure of MAE is lower than that of EAE. Since hydrophilicity of EAE might be higher than MAE because of their alkyl chain length, EAE has higher affinity for DEGDME than MAE and phase separation pressure become higher.
a)
b) 100
P_CO2 [kPa]
P_CO2 [kPa]
100
10
1
10
1
0.1
0.1 0
0.1
0.2
0.3
0.4
0.5
CO2 concentration [mol-CO2/mol-amine]
0.6
0
0.1
0.2
0.3
0.4
0.5
0.6
CO2 concentration [mol-CO2/mol-amine]
Fig. 5 CO2 solubility in a) EAE+DEGDEE, EAE+DEGDEM, b) MAE+DEGDME, EAE+DEGDEM at 313 K ▲: rich phase of EAE+DEGDME, ᇞ: lean phase of EAE+DEGDME, ♦: rich phase of EAE+DEGDEE, ◊: lean phase of EAE+DEGDEE, ●: rich phase of MAE+DEGDME, ○: lean phase of MAE+DEGDME Figure 6 shows the trend of phase separation. According to above results, higher hydrophobic amine and lower hydrophobic ether show the lower phase separation pressure.
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Ether hydrophobicity
Amine hydrophobicity
EAE DEGDEE
EAE DEGDME
Phase separation at lower pressure
MAE DEGDME
Fig. 6 Trend of phase separation about amine and ether hydrophobicity
4. Conclusion CO2 solubility of three type of phase separation solvent was measured. Phase separation pressure shows lower when higher hydrophobic amine and lower hydrophobic ether was selected. Now we plan to test the bench plant for phase separation type CO2 capture solvent. Acknowledgments This work was supported by ALCA, JST and KOBE STEEL, LTD. (KOBELCO).
REFERENCES
[1] A. Gomez, P. Briot, L. Raynal, P. Broutin, M. Gimenez, M. Soazic, P. Cessat, S. Saysset, Oil & Gas Science and Technology-Revue D Ifp Energies Nouvelles, 69 (2014) 1121-1129. [2] Y.E. Kim, J.H. Park, S.H. Yun, S.C. Nam, S.K. Jeong, Y.I. Yoon, J. Ind. Eng. Chem., 20 (2014) 1486-1492. [3] D.D.D. Pinto, H. Knuutila, G. Fytianos, G. Haugen, T. Mejdell, H.F. Svendsen, Int. J. Greenh. Gas Con., 31 (2014) 153-164. [4] D.D.D. Pinto, S.A.H. Zaidy, A. Hartono, H.F. Svendsen, Int. J. Greenh. Gas Con., 28 (2014) 318-327. [5] L. Raynal, P. Alix, P.A. Bouillon, A. Gomez, M.L. de Nailly, M. Jacquin, J. Kittel, A. di Lella, P. Mougin, J. Trapy, The DMX (TM) Process : An Original Solution for Lowering the Cost of Post-combustion Carbon Capture, in: J. Gale, C. Hendriks, W. Turkenberg (Eds.) 10th International Conference on Greenhouse Gas Control Technologies, 2011, pp. 779-786. [6] L. Raynal, P.A. Bouillon, A. Gomez, P. Broutin, Chem. Eng. J., 171 (2011) 742-752. [7] L. Raynal, P. Briot, M. Dreillard, P. Broutin, A. Mangiaracina, B.S. Drioli, M. Politi, C. La Marca, J. Mertens, M.L. Thielens, G. Laborie, L. Normand, Evaluation of the DMX Process for Industrial Pilot Demonstration Methodology and Results, in: T. Dixon, H. Herzog, S. Twinning (Eds.) 12th International Conference on Greenhouse Gas Control Technologies, Ghgt-12, 2014, pp. 6298-6309. [8] X.F. Wang, N.G. Akhmedov, D. Hopkinson, J. Hoffman, Y.H. Duan, A. Egbebi, K. Resnik, B.Y. Li, Appl. Energ., 161 (2016) 41-47.
ScienceDirect Energy Procedia 114 (2017) 823 – 826
13th International Conference on Greenhouse Gas Control Technologies, GHGT-13, 14-18 November 2016, Lausanne, Switzerland
Phase Separation Solvent for CO2 Capture Hiroshi Machidaa*, Takehiro Esakia, Kazuki Obaa, Takashi Tomikawaa, Tsuyoshi Yamaguchia, Hirotoshi Horizoea a
Department of Chemical Engineering, Nagoya University
Abstract We developed the new type of CO2 absorption solvent which transforms into two liquids phase with CO2 absorption. CO2 solubility of three types of phase separation solvent were measured and discussed about the hydrophobicity. © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license © 2017 The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of GHGT-13. Peer-review under responsibility of the organizing committee of GHGT-13. Keywords: CO2 capture; phase separation;
1. Introduction Carbon dioxide capture technology has been focused on applicable system for global worming problem. Amine scrubbing system was practically used in recent decades. In this system, most part of CO 2 separation energy is amine regeneration energy. To develop the energy saving system, there have reported several amine structures. Recently, phase separation type CO2 capture solvent has received an attention in recent years [1-8]. We developed the new type of CO2 absorption solvent which transforms into two liquids phase with CO2 absorption. Figure 1 shows CO2 separation process with our developed solvent. Flue gas contacts with solvent in absorption column. After absorption, CO2 dissolved solvent was separated to CO2 rich-phase and CO2 lean-phase. Only CO2 rich-phase was moved to desorption column and solvent was regenerated. Regenerated solvent and CO2 lean-phase was mixed and reused for CO2 absorption. Since CO 2 rich-phase shows high CO2 solubility and low water content, latent heat and sensible heat energy is expected to decrease. In this work, CO2 solubility of three types of phase separation solvent were measured and discussed about the hydrophobicity.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer-review under responsibility of the organizing committee of GHGT-13. doi:10.1016/j.egypro.2017.03.1224
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Hiroshi Machida et al. / Energy Procedia 114 (2017) 823 – 826
CO2
Treated gas
Bent
Flow meter
Absorber
Mixer
T
Condenser
Regenerator
CO2
Flue gas N2
Fig. 1 Process flow of phase separation type CO2 capture
Water bath
Stirrer
Fig.2 CO2 solubility measurement apparatus
2. Measurement Fig.2 shows an apparatus of CO2 solubility measurement. Solvent was loaded in the cell and temperature was controlled by a circulation thermostatic bath. CO2 and N2 mixed gas was flowed in the cell at ambient pressure. When the equilibrium reached, composition of liquid phase was analyzed with TOC, GC. If there shows two liquid phases, each phase were analyzed separately. We selected three types of phase separation solvent, EAE+DEGDEE, EAE+DEGDME, MAE+DEGDME. Temperature set to 313 K and pressure set to 1-100 kPa. CO2 solubility = mol-CO2 in lean or rich phase / mol-amine in both phase Table 1 Chemical formula and suppliers of materials Materials 2-(Ethylamino) ethanol
Supplier EAE
Chemical formula
TCI
2-(Methylamino) MAE WAKO ethanol Diethylene DEGDEE TCI Glycol Diethyl Ether Diethylene DEGDME TCI Glycol Dimethyl Ether TCI: Tokyo Chemical Industry CO.,Ltd., WAKO: Wako Pure Chemical Industries, Ltd.
3. Results and discussion Figure 3 shows the picture before and after CO2 absorption for solvent (EAE:DEGDEE:water = 3:6:1 weight base). Before CO2 absorption, solvent showed single liquid phase but after CO 2 absorption, it showed two liquid phases. Figure 4 shows the mechanism of phase separation with CO2 absorption. Carbamate salt which is produced by amine-CO2 reaction cannot dissolve in the ether phase and forms the second liquid phase.
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Hiroshi Machida et al. / Energy Procedia 114 (2017) 823 – 826
Before absorption
After absorption CO2
Ether solvent + water
CO2 CO2 R-NH
R-NH
CO2
CO2 lean
R-NH R-NH
Single liquid phase Fig. 3 Picture of phase separation solvent
CO2 rich
R-NH2+ R-NCO2䠉
Two liquid phase
Fig. 4 Mechanism of phase separation solvent
Figure 5 shows the CO2 solubility in phase separation solvent. There showed CO2 rich phase and CO2 lean phase. When EAE was selected for amine (Fig.5a), phase separation pressure of DEGDME is higher than DEGDEE. It caused by carbamate affinity for ether solvent. Since hydrophobicity of DEGDEE may be larger than that of DEGDME because of alkyl chain length, carbamate is smaller affinity for DEGDEE. When DEDME was selected for ether (Fig.5b), phase separation pressure of MAE is lower than that of EAE. Since hydrophilicity of EAE might be higher than MAE because of their alkyl chain length, EAE has higher affinity for DEGDME than MAE and phase separation pressure become higher.
a)
b) 100
P_CO2 [kPa]
P_CO2 [kPa]
100
10
1
10
1
0.1
0.1 0
0.1
0.2
0.3
0.4
0.5
CO2 concentration [mol-CO2/mol-amine]
0.6
0
0.1
0.2
0.3
0.4
0.5
0.6
CO2 concentration [mol-CO2/mol-amine]
Fig. 5 CO2 solubility in a) EAE+DEGDEE, EAE+DEGDEM, b) MAE+DEGDME, EAE+DEGDEM at 313 K ▲: rich phase of EAE+DEGDME, ᇞ: lean phase of EAE+DEGDME, ♦: rich phase of EAE+DEGDEE, ◊: lean phase of EAE+DEGDEE, ●: rich phase of MAE+DEGDME, ○: lean phase of MAE+DEGDME Figure 6 shows the trend of phase separation. According to above results, higher hydrophobic amine and lower hydrophobic ether show the lower phase separation pressure.
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Hiroshi Machida et al. / Energy Procedia 114 (2017) 823 – 826
Ether hydrophobicity
Amine hydrophobicity
EAE DEGDEE
EAE DEGDME
Phase separation at lower pressure
MAE DEGDME
Fig. 6 Trend of phase separation about amine and ether hydrophobicity
4. Conclusion CO2 solubility of three type of phase separation solvent was measured. Phase separation pressure shows lower when higher hydrophobic amine and lower hydrophobic ether was selected. Now we plan to test the bench plant for phase separation type CO2 capture solvent. Acknowledgments This work was supported by ALCA, JST and KOBE STEEL, LTD. (KOBELCO).
REFERENCES
[1] A. Gomez, P. Briot, L. Raynal, P. Broutin, M. Gimenez, M. Soazic, P. Cessat, S. Saysset, Oil & Gas Science and Technology-Revue D Ifp Energies Nouvelles, 69 (2014) 1121-1129. [2] Y.E. Kim, J.H. Park, S.H. Yun, S.C. Nam, S.K. Jeong, Y.I. Yoon, J. Ind. Eng. Chem., 20 (2014) 1486-1492. [3] D.D.D. Pinto, H. Knuutila, G. Fytianos, G. Haugen, T. Mejdell, H.F. Svendsen, Int. J. Greenh. Gas Con., 31 (2014) 153-164. [4] D.D.D. Pinto, S.A.H. Zaidy, A. Hartono, H.F. Svendsen, Int. J. Greenh. Gas Con., 28 (2014) 318-327. [5] L. Raynal, P. Alix, P.A. Bouillon, A. Gomez, M.L. de Nailly, M. Jacquin, J. Kittel, A. di Lella, P. Mougin, J. Trapy, The DMX (TM) Process : An Original Solution for Lowering the Cost of Post-combustion Carbon Capture, in: J. Gale, C. Hendriks, W. Turkenberg (Eds.) 10th International Conference on Greenhouse Gas Control Technologies, 2011, pp. 779-786. [6] L. Raynal, P.A. Bouillon, A. Gomez, P. Broutin, Chem. Eng. J., 171 (2011) 742-752. [7] L. Raynal, P. Briot, M. Dreillard, P. Broutin, A. Mangiaracina, B.S. Drioli, M. Politi, C. La Marca, J. Mertens, M.L. Thielens, G. Laborie, L. Normand, Evaluation of the DMX Process for Industrial Pilot Demonstration Methodology and Results, in: T. Dixon, H. Herzog, S. Twinning (Eds.) 12th International Conference on Greenhouse Gas Control Technologies, Ghgt-12, 2014, pp. 6298-6309. [8] X.F. Wang, N.G. Akhmedov, D. Hopkinson, J. Hoffman, Y.H. Duan, A. Egbebi, K. Resnik, B.Y. Li, Appl. Energ., 161 (2016) 41-47.