1、 GPA Technical Publication TP-28 Water Content of the CO2-rich Phase of Gaseous Mixtures Containing 10 and 20 Mole Percent CH4in CO2in Equilibrium with Water and/or Hydrate Kyoo Y. Song Rik Kobayshi Water G. Chapman Rice University Chemical Engineering Department-MS 362 George Brown School of Engine
2、ering P. O. Box 1892 Houston, Texas 77251 March 28, 2003 TABLE OF CONTENTS Page FOREWORD i GPA DISCALIMER ii LIST OF TABLES iii LIST OF FIGURES .iii 1.0 AUTHORS INTRODUCTION 1 2.0 RESULTS AND CONCLUSIONS 2 2.1 SCOPE 2 2.2 EXPERIMENTAL RESULTS 2 3.0 DISCUSSION OF RESULTS 2 4.0 EXPERIMENTAL DETAILS .
3、2 4.1 Experimentals . 2 5.0 EXPERIMENTAL PRECISION AND ACCURACY . 3 6.0 ACKNOWLEDGEMENT 3 7.0 REFERENCES . 3 8.0 APPENDIX 5 A-1 Table 1 . 5 B-1 Figures 1-3 6 Foreword This GPA Technical Progress Report contains experimental data for mixtures of carbon dioxide and methane. Professor Riki Kobayashi an
4、d his colleagues at Rice University obtained these data nearly twenty years ago for Shell Oil Company. Recently, GPA has funded additional studies at Rice to measure the liquid and vapor phase water, carbon dioxide, and hydrogen sulfide compositions in light hydrocarbon systems at conditions represe
5、ntative of gas processing and treating operations as part of Project 997. The data provided in this report complements the data that will be reported out as part of the GPAs 997 project. The GPA acknowledges Shell Oil Company for permission to release the data contained within this report. GPA Discl
6、aimer This technical progress report was prepared by Professor Walter Chapman of Rice University in co-operation with the GPA Research Committee. Neither GPA, Rice University, nor any person acting on behalf of either makes any warranty, guarantee or representation, express or implied, with respect
7、to the accuracy, completeness, or usefulness of the information contained in this report. The GPA and Rice University hereby expressly disclaim any liability or responsibility for loss or damage resulting from the use of any apparatus, method, or process disclosed in this report; and for the infring
8、ement of any patent or the violation of any federal, state or municipal law or regulation arising from the use of, any information, apparatus, method, or process disclosed in this report. “Copyright 2003 by Gas Processors Association. All rights reserved. No part of this Report may be reproduced wit
9、hout the written consent of the Gas Processors Association.“ LIST OF TABLES Table 1 Water Content of Carbon Dioxide-Rich Phase LIST OF FIGURES Figure 1 Line Sketch of Equilibrium Apparatus for V-L-E Study Figure 2 Line Sketch of Equilibrium Apparatus for V-L-S-E Study Figure 3 Analysis Apparatus iii
10、 1.0 AUTHORS INTRODUCTION Water content of the carbon dioxide (CO2)-rich phase for two gaseous mixtures, one containing ten and the other with twenty mole percent methane (CH4) in CO2has been measured at temperatures ranging from 30 to 60 F or 1.1 to 15.6 C and pressures ranging from 930 to 2100 psi
11、a or 64.1 to 144.8 bar, respectively. In a separate study prior to this study, the authors investigated the water content in the CO2 -rich phase composed of 5.31 mole percent methane and the balance carbon dioxide. It was found that the water content was drastically reduced from that in pure CO2due
12、to the presence of the diluent, methane. 2.0 RESULTS AND CONCLUSIONS 2.1 Scope The water content of the CO2-rich phase for the system of 9.97 mol % CH4 90.03 mole % CO2mixture with water (H2O) and of 20.09 mol % CH4-79.91 mole % CO2mixture with water for temperatures ranging from 30 to 60 F and pres
13、sures from 930 to 2100 psia have been measured. 2.2 Experimental Results The results on the water content of the CO2-rich phase for the system of 9.97 mole % CH4 90.03 mole % CO2mixture with water at temperatures from 30 to 57 F or 1.11 to 13.9 C for pressures from 2000 to 930 psia or 64.1 to 138 ba
14、r, respectively, are presented in Table 1. Similar results of the water content for the system of 20.09 mole % CH4- 79.91 mole % CO2at temperatures 30 to 60 F or 1.11 to 15.6 C, respectively, and for pressures from 2100 to 1800 psia equivalent to 145 to 124 bar, are presented in Table 1. The co-exis
15、ting equilibrium phases depending on the condition of pressure and temperature in this study are specified in Table 1. 3.0 DISCUSSION OF RESULTS As Table 1 shows, the water content for the mixtures containing 10 or 20 mol % methane in CO2is drastically reduced from the value of pure CO2system due to
16、 the presence of the diluent gas component, methane. 4.0 EXPERIMENTAL DETAILS 4.1 Experimentals In measuring the water content, an apparatus with a visual cell incorporating a magnet pump, which has been used for the V-L-E study of CH4-CO2system by Mraw et al. (1978)1, was used. It has been used sub
17、sequently for numerous V-L-E studies including the CH4-CO2-H2O system by Song and Kobayashi (1988)2for conditions above hydrate region. A line-diagram of the equilibrium apparatus is presented in Figure 1. When the equilibrium condition fell on or below the initial hydrate formation condition a seco
18、nd equilibrium apparatus was employed. It has been previously applied for pure CH4-, CH4-C3H8-, and pure CO2-hydrate systems by Sloan et al. (1976)3and Aoyagi et al. (1979)4, and Song and Kobayashi (1982, 1987)5,6, respectively. The apparatus was equipped with a blind cell containing a number of sta
19、inless steel balls of different size to grind the hydrate crystals and thereby eliminate metastable liquid water from the system by rotating and counter rotating over an extended period of time. The electric motor drive formerly used for the alternate rotation was replaced by a trouble-free air-driv
20、en sprocket arrangement, resulting in a significant improvement in the performance of the apparatus. A line diagram of the equilibrium apparatus is shown in Figure 2. The concentration of moisture in the CO2-rich phase was measured with a special water analysis scheme devised by Bloch and Lifland (1
21、973)7 5.0 EXPERIMENTAL PRECISION AND ACCURACY The bath temperature was controlled to better than 0.05 C with a thermotrol manufactured by Hallikainan Instruments Co., and the temperature was measured with an L SN 1331413) whose calibration is traceable to an NIST-certified PRT within 0.005 C. A Mull
22、er Bridge, L &N Model 8067m and DC Null Detector 9834 were connected to the PRT. The system pressure was measured by a pressure transducer manufactured by Setra Systems, Inc., model 204 with a pressure range of 0 to 3000 psia and certified to be better that 0.1 % of the measured values in its full s
23、cale. A certified grade gas mixtures of 9.97 mol % and 20.09 mol % methane in CO2with better than 0.05 % were purchased from ARCO Gas Co. Triply distilled water was used throughout the studies. Ultra grade helium was used as a carrier gas and was purchased from the U.S. Bureau of Mines. Its minimum
24、purity was stated to be 99.999 mol %. And the gas mixture from the supply containers was drawn through a filter-gas purifier, Model 452 of Matheson Gas Products. The value of water content for each condition represents an average of 5 to 10 measurements with a deviation of 3 to 5 %. The accuracy of
25、the tabulated water content based on the calibration and other factors is estimated to be generally within 5 to 6 % for all of the experimental results. 6.0 ACKNOWLEDGEMENT We gratefully acknowledge the generous support of the Shell Oil Co for this project. 7.0 REFERENCES 1. Mraw, S. C., Hwang. S. C
26、., and Kobayashi, R., “The Vapor-Equilibrium of CH4-CO2System at Low Temperatures”, J. Chem. Eng. Data 23, 135-139 (1978). 2. Song, K. Y. and Kobayashi, R., “Water Content Values of a CO2-5.31 mol % Methane Mixture”, RR-120, Oct. 1988, GPA, Tulsa, Ok. 3. Sloan, E. D., Khoury, F., and Kobayashi, R.,
27、“Water Content of Methane Gas in Equilibrium with Hydrates”, Ind. Eng. Chem., Fund. 15(4), 318-22 (1976). 4. Aoyagi, K., Song, K. Y., Sloan, E. D., Dharmawardhana, P. B., and Kobayashi, R., “Improved Measurements and Correlation of the Water Content of Methane Gas in Equilibrium with Hydrate”, Prepr
28、inted and Presented at 58thAnnual GPA Convention, March 19-21, 1979, Denver, Co. 5. Song, K. Y. and Kobayashi, R., “Measurement and Interpretation of the Water Content of a Methane-Propane Mixture in the Gaseous State in Equilibrium with Hydrate.” Ind. Eng. Chem. Fund. 21(4), 391-95 (1982). 6. Song,
29、 K. Y. and Kobayashi, R., “Water Content of CO2in Equilibrium with Liquid Water and /or Hydrates”, SPE Formation Evaluation 500-508, Dec. 1987. 7. Bloch , M. G. and Lifland, P. P., “Catalytic Reforming Improved by Moisture Metering”, Chem. Eng. Prog., 69(9), 49-52 (1974). 8.0 APPENDIX Table 1 Water
30、Content in CO2-rich Phase _ Mol % CH4t, P, Water Content Equil. Phase Remarks in F/ C psia/bar Lbm/MMSCF Phases sampled CO2at 1 atm/60 F _ 9.97 57/13.9 930/64.1 39.41 L-Lw-V L 71.1a“ 45/7.22 950/65.5 36.90 L-H L 61.6a“ “ 2000/138 80.27 L-H L 156.4a“ 30/-1.11 “ 62.41 L-H L 120.4a20.09 60/15.6 1200/82.8 42.61 L-LwL 137.4a, 82.4b“ “ 1800/124.1 60.76 L-LwL 107.3b“ 30/-1.11 1200/82.8 30.54 L-H L 91.0a“ “ 1800/124.1 34.45 L-H L “ “ 2100/144.8 40.68 L-H L 125.6a _ a water content in pure CO2(Song and Kobayashi, 1987), b water content in the mixture of 5.31 mol % CH4in CO2(Song and Kobayashi, 1988).
