1、Technical Publication 4iiiFJ9 TP-9 Gas The Water Content and the Solubility of CO2 in Equilibrium with DEG-Water and TEG-Water “ Solutions at Feasible Absorption Conditions , Pro c e s 8 ors A ssoc i at ion 1812 First Place ?. c Tulsa. Okla. 74103 Shinji Takahashi Riki Kokyashi Rico UnMi Haurtari,li
2、cas lhcemkr. 1982 Phone: 918/582-5112 GPA TP-9 82 3824677 003rlL27 258 = FOREWORD The experimental investigations summarized in the ensuing report was neither spon- sored or financed by GPA, hence, the information is issued as a Technical Publication (TP -9 ) rather than our conventional Research Re
3、port. Glycols are commonly used in the gas processing industry for the dehydration of natural gases to achieve acceptable water specifications for transmission in pipelines. The dehydration of CO2-rich gases for transmission and handling require specifications that are peculiar to CO2 and to the con
4、ditions under which it is to be transported. This report presents basic phase equilibria data on the ability of DEG and TEG to dehydrate CO2 at feasible absorption conditions. The water content of the CO2-rich fluids in equilibrium with liquid water or hydrates sets the acceptable water content spec
5、ification while the water content of the CO2-rich fluid in equilibrium with the glycols-water solution presented in this work provides the water concentration achievable in the dehydration process. The solubility of carbon dioxide in the glycol and glycol-water solutions at high pressures is appreci
6、able, hence must be taken into account both in the absorption and stripping aspects of the process. The CO2 solubility data are also necessary in explaining the unusual dehydration qualities of the glycols for COz. The GPA and the Authors thank the Arco Oil and Gas Company who financed these studies
7、 for permission to publish this work. i earl Sutton, Secretary GPA TP-9 82 3824699 0011128 194 I TABLE OF CONTENTS FOREWORD . AUTHORS INTRODUCTION EXPERIMENTAL RESULTS . EXPERIMENTAL APPARATUS / PROCEDURE / REAGENTS Apparatus . Procedure . Reagents REMARKS REFERENCES . LIST OF TABLES AND TABLES . LI
8、ST OF FIGURES AND FIGURES . Page i 1 1 3 4 5 5 6 7 12 GPA TP-9 82 3824b99 0011127 020 = AUTHORS INTRODUCTION The water content of CO2 in equilibrium 3.5 wt % H20 and 7.0 wt % %O in both DEC and TEC have been measured to pressures as high as 1165 psia at temperatures of 75, 100, and 120F. These exper
9、imental data have been combined with the experimental data on the CO2-water system Wiek and Gaddy, 1941, Takenouchi and Kennedy, 1961, and Todheide and Franck, 1963 to present the water content of the C02-rich fluid phase over the entire concentration range from pure glycol to pure water. Measuremen
10、ts of the solubility of COt in the glycol-water solutions were carried out at similar conditions to provide data which are needed for process calculations and in quantitatively explaining the unusual dehydration hypothesis of the glycols for COz. Two important categories of information have not been
11、 obtained: (1) (2) solutions. the effect of pressure on the glycol vaporization losses, and calorimetric data on the heats of solutions of CO2 in the glycol-water The former are important, because absorption conditions in which the CO2 phase densities approach liquid-like densities are being propose
12、d. The heats of solution of the CO2 in the glycol-water solution reaction are important because of the high solubility of CO2 in the glycol solutions. EXPERIMENTAL RESULTS The water content of the CO2-rich fluid phase in equilibrium with 3.5 and 7.0 weight percent water in TEG and DEG solutions were
13、 measured at 75, 100, and 120F at pressures of 365, 565, and 765 psia. Measurements were also carried out at 120F and 1165 psia. 1 GPA TP-9 82 11811 3824b9 001LL30 842 The solubility of carbon dioxide in the liquid solutions were measured at conditions indentical to those listed above. The water con
14、tent data are summarized in Tables I and II. Interpolated literature values from the earlier studies of Wiek and Gaddy, 1941, are included in the tables. The CO2 solubility data are summarized in Tables III and Tables IV. Experimental data on the solubility of CO2 in pure TEG and in pure DEG were co
15、mbined with the CO2 solubility data of Wiebe and Caddy, 1941, in pure liquid water to give the terminal pure component solubility values shown in Tables III and Tables IV. The experimental water content values were first plotted as log water content versus log pressure curves shown in Figures 2 thro
16、ugh Figures 5. Superimposed on the same curves are the water content values obtained from an enlarged version of the water content curves for natural gas obtained from Figure 5-8 of the Handbook of Natural Gas Engineering, McGraw-Hill, Katz, et al., (1959). The log water content versus log pressure
17、curves for natural gas in particular, provided valuable “reference slopes.“ The log water content versus log pressure curves indicate that there will be a pressure at which the dehydration qualities of the glycols for natural gas exceeds the dehydration qualities for COz. This results from the fact
18、that CO2 is so much more incompressible than natural gas at high pressures at these temperatures. Figures 6 through 9 present log water content versus 1/T plots to show their near linear, parallel behavior. The tabulated water contents, together with the assumption that the water content of CO2 in e
19、quilibrium with the anhydrous glycols would be zero, led to the construction of Figures 10 through Figure 17. The curves are not as well ibrium with TEGH20 Solution, Ibs H20/MMCF Cb, at 60 F, 14.7 psia Summary of Data on Water Content in CO infquilibrium with Summary of SO2 Solubility Data in TEGWaJ
20、er Solution, 8 II DEGHZO Solution, Ibs H20/MMCF CO2 a360 F, 14.7 psia 9 III ml CO2 at 60 F, 14.7 psia/ml solution at 60 F 10 N Summary of SO2 Solubility Data in DEGWger Solution, ml CO2 at 60 F, 14.7 psia/ml Solution at 60 F 11 7 GPA TP-9 82 W 3824699 0011136 260 TABLE I. Summary of Data on Water Co
21、ntent in CO2 in Equilibrium with TEG -H20 Solution, lbs H20/MMCF CO2 at 60F, 14.7 pia w% H20 in solution mol % H20 in solution 75F 365 psia 565 psia 765 psia 100F 365psia 565 pia 765 psia 120F 365 pia 565 psia 765 psia 1165 pia 3.5 23.23 8.64 7.05 6.19 19.6 15.6 14.7 34.6 29.6 27.5 26.6 * R. Wiebe a
22、nd V.L. Caddy; LACS, 63, 475 (1941). 7.0 38.58 17.6 15.0 13.1 38.8 29.0 25.6 64.8 49.3 42.2 37.9 loo* 1 O0 73 64 59 152 113 1 O0 280 200 169 174 TABLE II Summary of Data on Water Content in CO2 in Equilibrium with DEC-H20 Solution, Lbs H20/MMCF CO2 at 60F, 14.7 psia w% H20 in Solution mol % i-$O in
23、Solution 75F 365 psia 565 psia 765 psia 1 OOF 365 psia 565 psia 765 psia 1 20F 365 psia 565 psia 765 pia 1165 pia 3.5 17.61 9.29 6.83 6.12 18.3 13.1 11.5 29.5 22.9 20.5 17.9 7.0 30.73 18.3 13.2 12.3 31.5 23.3 20.8 58.3 39.1 32.7 28.4 100“ 1 O0 73 64 59 152 113 1 O0 280 200 169 174 * R. Wiebe and V.L
24、. Caddy, J. ACS, 63, 475 (1941). 9 GPA TP-9 82 W 382Lib99 OOLLL38 033 D TABLE III Summary of CO2 Solubility Data in TEG-Water Solution, ml CO2 at 60F, 14.7 psia/ml solution at 60F w% H20 in Solution mol % H20 in Solution 75F 365 psia 565 psia 765 psia 100F 365 psia 565 psia 765 psia 120F 365 psia 56
25、5 psia 765 psia 1165 psia 0.0 0.0 46.3 76.4 113.8 31.9 57.6 84.9 29.8 48.8 69.5 133.7 CC of co2 at OC, i atm/g Soiution w% H20 in Solution mol % H20 in Solution 75F 365 psia 565 psia 765 psia 100F 365 psia 565 psia 765 psia 120F 365 pia 55 pia 765 pia 1 i65 psia 0.0 0.0 38.8 64.1 95.4 26.8 48.3 71.2
26、 25.0 40.9 58.3 112.1 3.5 23.23 40.2 67.4 98.2 28.3 46.5 68.1 23.3 38.1 56.0 97.0 3.5 23.23 33.80 56.7 82.6 23.8 39.1 57.3 19.6 32.0 47.1 81.6 7.0 38.58 33.3 56.6 81.2 25.2 42. I 58.0 23.3 39.5 56.4 88.6 7.0 38.58 28.1 47.7 68.4 21.2 35.5 48.9 19.6 33.3 47.5 68.7 100 * 1 O0 16.86 23.76 28.44 12.12 1
27、7.28 21.23 9.70 14.50 18.34 23.20 * R. Wick and V.L. Caddy, J.ACS, 61,315 (1939). ibid, 62, 815 (1940). 10 GPA TP-9 82 m 3824b99 OOLLL39 T7T m TABLE IV Summary of CO2 Solubility Data in DEG-Water Solution, ml CO2 at 60F, 14.7 psia/ml Solution at 60F w% H20 in Solution 0.0 3.5 mol % H20 in Solution 0
28、.0 17.61 75F 365 psia 565 psia 765 psia 100F 365 psia 565 psia 765 psia 120F 365 psia 565 psia 765 psia 1165 psia 39.9 67.5 106.0 31.1 51.0 76.5 24.8 41.1 59.3 110.5 CC of co2 at OOC, i atm/g Soiution w% H20 in Solution mol % H20 in Solution 75F 365 psia 565 psia 765 pia 100F 365 pia 565 pia 765 psi
29、a 120F 365psia 565 psia 765 pia 1165 psia 0.0 0.0 33.7 57.0 89.5 26.3 43.1 64.6 20.9 34.7 50.1 93.3 34.9 59.9 86.8 27.3 42.1 62.7 24.5 38.2 53.1 85.5 3.5 17.61 29.5 50.7 73.5 23.1 35.6 53.1 20.7 32.3 44.9 72.4 7.0 30.73 31.8 52.5 74.9 25.8 40.0 60.2 20.3 33.6 50.9 80.9 7.0 30.73 26.9 44.5 63.5 21.9
30、33.9 51.0 17.3 28.5 43.1 68.6 100.0 100.0 17.8 25.1 30.0 12.8 18.2 22.4 10.2 15.3 19.4 24.5 100“ 1 O0 16.86 23.76 28.44 12.12 . 17.28 2 1.23 9.70 14.50 18.34 23.20 * Wiek and V.L. Gaddy, J. ACS, 61, 315 (1939). ibid, 62, 8 15 ( 1940). 11 GPA TP-9 2 3824699 OOLLL40 791 LIST OF FIGURES Finure No. Des
31、cr ipt ion Page No. 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 Schematic Diagram for Recycle Vapor-Liquid Equilibrium Apparatus 1. Water Content of CO2 in Equilibrium with TEG 3.5 wt% H20 Solution (constant Temp) Water Content of CO2 in Equilibrium with TEG 7.0 u% H20 (constant T 1 2. 3.
32、Water Content in CO2 in Equilibrium with DEG-3.5 u% H20 Solution (constant T). 4. Water Content in CO2 in Equilibrium with DEG-7.0 u% H20 Solution (constant T). 5. 6. Water Content of CO2 in Equilibrium with TEG 3.5 wt% H20 Solution. (Constant P) Water Content of CO2 in Equilibrium with TEG 7.0 u% H
33、20 (constant P 1 7. 8. Water Content in CO soiut ion (constant $ ) . in Equilibrium with DEG-3.5 w% H20 9. Water Content in CO2 in Equilibrium with DEG-7.0 u% H20 Solution (constant P). 10. Water Content in CO2 in Equilibrium with TEG-Water Solution at 365 psia. (Constant T) li. Water Content in CO2
34、 in Equilibrium with TEG-Water Solution at 565 psia. (Constant T) 12. Water Content in CO2 in Equilibrium with TEG-Water Solution at 765 psia. (Constant T) 13. Water Content in CO2 in Equilibrium with TEG-Water Solution at 1165 psia. (Constant T) 14. Water Content in CO2 in Equilibrium with DEG-Wate
35、r Solution at 365 psia. (Constant T) Water Content in CO2 in Equilibrium with DEG-Water Solution at 565 psia. (Constant T) 15. 16. Water Contert in CO2 in Equilibrium with DEG-Water Solution at 765 psia. (Constant T) 17. Water Content in CO2 in Equilibrium with DEG-Water Solution at 1165 psia. (Cons
36、tant T) 18. Water Content in Gaseous Phase in Equilibrium with TEG- Water Solution at 365 psia. (Constant T) 12 GPA TP-9 82 3824b93 OOLLL4L 628 Fiwe No. Des cr ipt ion Page No. 32 19. Water Content in Gaseous Phase in Equilibrium with TEG-Water Solution at 565 psia. (Constant T) 20. Water Content in
37、 Gaseous Phase in Equilibrium with TEG-Water Solution at 765 psia. (Constant T) 33 21. Water Content in Gaseous Phase in Equilibrium with DEG-Water Solution at 365 psia. (Constant T) 34 22. Water Content in Gaseous Phase in Equilibrium with DEG-Water Solution at 565 psia. Water Content in Gaseous Ph
38、ase in Equilibrium with DEG-Water Solution at 765 psia. (Constant TI (Constant T) 35 23. 36 CO2 Solubility in Pure TEG. (Constant T) 37 38 39 40 41 42 43 24. 25. 26. 27. 28. 29. 30. CO2 Solubility in TEG 3.5 wt% H20 (constant TI. CO2 Solubility in TEG 7.0 wt% H20 (constant TI. CO2 Solubility in Pure
39、 DEG. CO2 Solubility in DEG-3.5 wt% H20 (constant T). CO2 Solubility in DEG 7.0 wt% H20 (constant TI. CO2 Solubility in TEG H20 Solution at 75OF. stant P) (Con- CO2 Solubility in TEG H20 Solution at 1OOOF. stant P ) (Con- 31. 44 32. CO2 Solubility in TEG-H20 Solution at 12OOF. stant Pl (Con- 45 33.
40、CO2 Solubility in DEG-H20 Solution at 75pF. stant P) (Con- 46 34. CO2 Solubility in DEG-H20 Solution at 10OOF. stant P) CO20 Solubility in DEG-H20 Solution at 12DF. (Constant P) (Con- 47 35. 48 13 GPA TP-9 82 I 3824b99 OOLlL42 564 a W A J O p: I- Y O O O O a c a cn cn J a a Q Q. e Q w A o * o W a 14
41、 GPA TP-9 82 = 3824679 0011143 4T0 100 90 80 70 60 50 40 30 20 15 10 9 8 7 6 5 4 3 2 I I I I I111 I I 1 =X 120 O F IOO*F 75 OF -1 1 200 300400 1000 1500 PRESSURE psia Fig. 2 Water Content of CO2 in Equilibrium with TEG 3.5 wt% H20 Solution (constant Temp) 15 GPA TP-7 82 I 3824679 001LL44 337 -3 100
42、90 80 Q 70 60 50 40 30 20 15 I I I I I111 I 200 300400 1000 1500 PRESSURE psia 38. 3 Water Content of CO2 in Equilibrium with TEG 7.0 w% H20 (constant T) 16 70 60 50 40 30 20 10 9 8 7 6 5 4 3 2 GPA TP-9 82 - 3824699 0011145 273 -o- - 12OoF NAT, GAS I I I I I 1111 I 200 300400 700 1000 1500 PRESSURE
43、psia Fig. 4 Water Content in CO2 in Equilibrium with DEG3.5 w% H20 Solution (constant TI. 17 .o o 100 3 90 80 qf ?O - 60 li- o 50 IC (o s 40 IO 30 20 4- GPA TP-9 2 W 3824699 OOLLL4h LOT i I I I I I I III I I I I I I IlII I - 1 5t Fig. 5 Water Content in CO2 in Equilibrium with DEC-7.0 w% H20 Solutio
44、n c (constant T) . i8 - a a 3 W I- too 90- 80 70 60 50 40 30- 20 15 IO 9- 8- 7- 6- 5- 4- 3- 2- Fig. 6 60 70 80 90 I00 110 120 130140 I I I I I I I I - - = - - - - - I I I I I GPA TP-9 2 E 3824699 OOLLL47 046 TEMPERATURE, OF 365 765 psis 33 3.4 3.3 3.2 3,l 3.0 2,9 TEMPERATURE, WK) x 103 Water Content
45、 of CO2 in Equilibrium with TEG 3.5 wt % H20 Solution. (C -mt P) 19 GPA TP-9 2 m 3824b99 OOLLL48 T2 m 80 70 60 50 40 20 15 IO 9 0 7 6 5 d TEMPERATURE OF O 365 565 765 0- 0 CO2 -0- psia I I I I I I 3.5 3.4 383 3.2 38 I 3,O 2.9 4 TEMPERATURE, (VK) x 103 Fig. 7 Water Content of CO2 in Equilibrium with
46、TEG 7.0 w% H20 (constant P) 3n IO0 90 80 a IL 0 30 O (D 0 20 cn = 10 -9 O o7 c 5 TEMPERATURE, OF 365 565 765 psia psia psia Fig. 8 Water Content in CO2 in Equilibrium with DEG-3.5 w% H20 Solution (constant w. 21 GPA TP-7 82 m 3824677 0011150 630 m 60 70 80 90 100 110 120 130 140 L I l I I I I l I I
47、- I .) - - I . I I I I I 100 90 80 70 60 50 40 30 20 8 a 7 6 5 4 3 TEMPERATURE, OF 365 psia O0 384 3.3 32 3, I 380 TEMPERATURE, (VK) x 103 Fig. 9 Water Content in CO2 in Equilibrium with DEE7.0 w% H20 Solution (constant Pl. 22 GPA TP-9 82 3824699 OOLLLSL 577 li O O (D t O c L1L w I- U 3 O 0, 5 I ao
48、MOLE FRACTION OF H20 Fig. 10 Water Content in COz in Equilibrium with TEG-Water Solution at 365 psia. (Constant T) 23 300 200 GPA TP-9 82 E 3824699 OOLLL52 403 I O0 O O Ot5 I to MOLE FRACTION OFHg Fig. 11 Water Content in CO2 in Equilibrium with TEC-Water Solution at 565 psia. (Constant TI 24 GPA TP
49、-9 82 = 3824b99 OOLLL.53 34T E 150 I 100 I / I / / / / / / / / tf MOLE FRACTION OF H20 Fig. 12 Water Content in CO2 in Equilibrium with TEGWater Solution at 765 psia. (Constant T) 25 GPA TP-9 82 B 3824677 0011154 28b U .- Q 200 150 O I I I / I I I I / I / / I 1 I O 03 I ,o MOLE FRACTION OF H20 Fig. 13 Water Content in CO2 in Equilibrium with TEG-Water Solution at 1165 psia. (Constant TI 26 GPA TP-9 82 3824699 OOLLL55 LI2 300 200 / / / I / / I / - 100 O Fig. 14 Water Content (Constant T) O 015 It0 r
