DOCSLIB.ORG

Carbon Isotope Fractionation During the Formation of CO2 Hydrate and Equilibrium Pressures of 12CO2 and 13CO2 Hydrates

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Carbon Isotope Fractionation During the Formation of CO2 Hydrate and Equilibrium Pressures of 12CO2 and 13CO2 Hydrates molecules Article Carbon Isotope Fractionation during the Formation of CO2 12 Hydrate and Equilibrium Pressures of CO2 and 13 CO2 Hydrates Hiromi Kimura 1, Go Fuseya 1 , Satoshi Takeya 2 and Akihiro Hachikubo 3,* 1 Kitami Institute of Technology, Graduate School of Engineering, 165 Koen-cho, Kitami 090-8507, Japan; [email protected] (H.K.); [email protected] (G.F.) 2 National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST), Central 5, Higashi 1-1-1, Tsukuba 305-8565, Japan; [email protected] 3 Environmental and Energy Resources Research Center, Kitami Institute of Technology, 165 Koen-cho, Kitami 090-8507, Japan * Correspondence: [email protected] Abstract: Knowledge of carbon isotope fractionation is needed in order to discuss the formation and dissociation of naturally occurring CO2 hydrates. We investigated carbon isotope fractionation during 12 13 CO2 hydrate formation and measured the three-phase equilibria of CO2–H2O and CO2–H2O systems. From a crystal structure viewpoint, the difference in the Raman spectra of hydrate-bound 12 13 13 CO2 and CO2 was revealed, although their unit cell size was similar. The δ C of hydrate-bound CO2 was lower than that of the residual CO2 (1.0–1.5‰) in a formation temperature ranging between 226 K and 278 K. The results show that the small difference between equilibrium pressures of Citation: Kimura, H.; Fuseya, G.; 12 13 ~0.01 MPa in CO2 and CO2 hydrates causes carbon isotope fractionation of ~1‰. However, the Takeya, S.; Hachikubo, A. Carbon 12 13 difference between equilibrium pressures in the CO2–H2O and CO2–H2O systems was smaller Isotope Fractionation during the than the standard uncertainties of measurement; more accurate pressure measurement is required Formation of CO2 Hydrate and 12 for quantitative discussion. Equilibrium Pressures of CO2 and 13 CO2 Hydrates. Molecules 2021, 26, 4215. https://doi.org/10.3390/ Keywords: CO2 hydrate; carbon isotope; isotopic fractionation; phase equilibrium; Raman spectra molecules26144215 Academic Editors: Nobuo Maeda, Zhiyuan Wang and Xiaodong Shen 1. Introduction Gas hydrates are crystalline clathrate compounds that have guest gas molecules Received: 11 June 2021 encapsulated in hydrogen-bonded water cages and can be thermodynamically stable Accepted: 7 July 2021 at high pressures and low temperatures. The phase equilibrium pressure-temperature Published: 11 July 2021 conditions vary depending on the guest molecule type [1]. Gas hydrates with encapsulated natural gases exist in sub-marine/sublacustrine sediments and below the permafrost on Publisher’s Note: MDPI stays neutral Earth. Because they contain copious amounts of greenhouse gases, such as methane, with regard to jurisdictional claims in concerns arose that their dissociation could add to global warming [2–4]. Hydrate-bound published maps and institutional affil- gas contains both hydrocarbons and CO2 [5–7], and natural gas hydrates encapsulating iations. CO2 have been observed at the venting sites of liquid CO2 [8,9]. On the other hand, the possibility of existing CO2 hydrates on Mars was proposed [10,11] and the conditions for CO2 hydrate formation on Mars have been discussed [12]. As above, CO2 hydrates are critical in both geochemistry and space science and require better understanding. Copyright: © 2021 by the authors. Since CO2 comprises carbon and oxygen atoms, several isotopic species of CO2 Licensee MDPI, Basel, Switzerland. exist, depending on the combination of stable isotopes (isotopologues: 12C, 13C, 16O, This article is an open access article 17 18 13 O, and O). For example, the abundance ratio of CO2 is ~1.1% of the total CO2 and distributed under the terms and 12 the rest is almost CO2. Stable isotope fractionation of the guest gas during the gas conditions of the Creative Commons hydrate formation provides information for discussing the formation, maintenance, and Attribution (CC BY) license (https:// decomposition processes of gas hydrates. For example, the trend of hydrogen and carbon creativecommons.org/licenses/by/ isotope fractionation during the formation of synthetic methane and ethane hydrates was 4.0/). Molecules 2021, 26, 4215. https://doi.org/10.3390/molecules26144215 https://www.mdpi.com/journal/molecules Molecules 2021, 26, 4215 2 of 8 investigated [13]. Moreover, the results were applied to estimate the formation process of natural gas hydrates [14–16]. Carbon isotope fractionation during the formation of 13 CO2 hydrates was reported [17], revealing that the CO2 δ C in the hydrate phase was 12 0.9‰ lower than that in the gas phase at 268 K [17]. Therefore, CO2 is more easily 13 encapsulated in the hydrate phase than CO2. Because the temperature of existing natural gas hydrates at sea/lake bottom sediments is above 273 K, information about carbon isotope fractionation above the freezing point of water is needed to discuss the formation and dissociation of naturally occurring CO2 hydrates. Furthermore, CO2 hydrates have been suggested outside of Earth. Therefore, it is also necessary to confirm isotope fractionation in a wider temperature range. In studies on methane hydrates, the equilibrium pressures of CH3D and CD4 hydrates were ~0.04 MPa and ~0.14 MPa higher than those of the CH4 hydrate, respectively [18]. Because guest molecules, which have lower equilibrium pressure, are preferentially en- capsulated in the gas hydrate cages, the difference in equilibrium pressures of CH3D and CH4 hydrates can explain the hydrogen isotope fractionation in methane during methane hydrate formation [18]. Thus, comparing the phase equilibrium p–T conditions of each gas hydrate encapsulating isotopologues can explain the trend of isotopic fractionation of 13 guest gases during gas hydrate formation. However, the equilibrium pressure of CO2 hydrates has not been reported. In this study, we synthesized gas hydrate samples, encapsulated CO2 isotopologues 12 13 ( CO2 and CO2), and characterized their crystallographic properties using powder X-ray diffraction (PXRD) and Raman spectroscopy. We also measured the equilibrium 12 13 pressures of CO2 and CO2 hydrates at a temperature range between 269 K and 278 K. We investigated carbon isotope fractionation between hydrate-bound gas and residual gas in a pressure cell in the temperature range of 226 K to 278 K. 2. Results and Discussion 12 13 We confirmed the crystallographic structures of CO2 and CO2 hydrates and ob- tained their lattice constants using the PXRD method. The diffraction patterns of cubic structure I (sI) hydrates were observed from these hydrates (Figure S1). The lattice constants 12 13 of CO2 and CO2 hydrates were similar at 11.8352(6) Å and 11.8323(5) Å, respectively. 12 13 Figure1 shows the Raman spectra of CO2 and CO2 hydrates and Table1 summa- rizes the observed Raman shifts of hydrate-bound isotopologue CO2 and their assignments to the vibrational modes. Two distinct peaks corresponding to the Fermi dyad of CO2 −1 −1 12 in the hydrate cages were observed at 1278.2 cm and 1381.9 cm for CO2 hydrates, corresponding to [19–21]. These peaks shifted to 1256.4 cm−1 and 1365.8 cm−1 for the 13 −1 CO2 hydrate. Qin and Kuhs [21] observed 1366.6 ± 4.0 cm for the upper Fermi dyad of 13 hydrate-bound CO2, and our data were consistent with their results. Definite differences (22 cm−1 and 16 cm−1 for lower and upper peaks, respectively) were found between these 12 13 Raman peaks caused by the encapsulated CO2 and CO2 molecules. Table 1. Observed Raman shifts of hydrate-bound CO2 and assignments to the vibrational modes. Raman Shift Raman Shift Guest Molecule Assign Vibrational Mode Gas/cm−1 Hydrate/cm−1 a 12 1285.40 [22] 1278.2 , 1277 [19], 1278 [20], 1275.5 ± 0.8 [21] CO2 a 1388.15 [22] 1381.9 , 1381 [19], 1382 [20], 1379.4 ± 0.8 [21] b CO s-stretch υ1 + 2υ2 b 1266.03 [22] 1256.4 a + bend 13CO 2 1369.90 [22] 1365.8 a, 1366.6 ± 4.0 [21] a This work, uncertainty is <1.1 cm−1. b Fermi resonance. MoleculesMolecules2021 2021,,26 26,, 4215x FOR PEER REVIEW 33 of 88 12 CO2 hydrate Intensity /a.u. Intensity 13 CO2 hydrate 1200 1300 1400 1500 Raman Shift /cm−1 1212 13 FigureFigure 1.1. Raman spectraspectra ofof CO2 and COCO22 hydrateshydrates in in the the CO CO stretching stretching vibration mode region ofof 2 COCO2. The The spectra spectra were were recorded at atmospheric pressure and 140140 K.K. (a.u.,(a.u., arbitraryarbitrary units).units). Table2 2 lists lists and and Figure Figure2 2plots plots the thep p––TT datadata forfor thethe three-phasethree-phaseequilibrium equilibrium (ice/water (ice/water 1212 1313 ++ hydratehydrate ++ vapor)vapor) forfor thethe COCO22–H–H22O and CO22–H–H22OO systems. systems. The The phase phase in in the equilib- 12 riumrium ofof eacheach pointpoint inin TableTable2 2was was determined determined using using the the quadruple quadruple point point of of the the 12COCO22–H–H22OO systemsystem (1.04(1.04 MPa MPa and and 271.6 271.6 K) K) reported reported by [by23 ].[2 To3]. ensureTo ensure the accuracy the accuracy of the of experimental the experi- apparatusmental apparatus described described in the previous in the previous section, section, we evaluated we evalua the equilibriumted the equilibriump–T data p– ofT 12 dataCO 2ofhydrates. 12CO2 hydrates. From Figure From2 Figure, they correlate 2, they correl well withate well the with literature the literature [ 23–26]. [23–26]. The equilib- The 13 riumequilibrium pressures pressures in the inCO the2–H 13CO2O2–H system2O system are higher are higher by 0.007–0.012 by 0.007–0.012 MPa comparedMPa compared with 12 thewith corresponding the corresponding values values in the in theCO 212–HCO22O–H system2O system between between 269 K269 and K and 278 K.278 However, K.
Load more

Recommended publications
  • Temperature- and Pressure-Dependent Structural Transformation of Methane Hydrates in Salt Environments
    PUBLICATIONS Geophysical Research Letters RESEARCH LETTER Temperature- and pressure-dependent structural 10.1002/2016GL072277 transformation of methane hydrates Key Points: in salt environments • Under a low-pressure condition, the methane hydrate is decomposed Donghoon Shin1 , Minjun Cha2 , Youjeong Yang3, Seunghyun Choi1, Yesol Woo1 , through a rapid sublimation of water 4 5 6 6 7,8,9 1,3 from the surface of hydrate crystals Jong-Won Lee , Docheon Ahn , Junhyuck Im , Yongjae Lee , Oc Hee Han , and Ji-Ho Yoon • The hydrated salt of NaCl · 2H2O 1 undergoes a phase transition into a Department of Energy and Resources Engineering, Korea Maritime and Ocean University, Busan, South Korea, crystal growth of crystalline NaCl via 2Department of Energy and Resources Engineering, Kangwon National University, Chuncheon, South Korea, 3Department the migration of salt ions of Convergence Study on the Ocean Science and Technology, Ocean Science and Technology School, Korea Maritime and • The methane hydrate is fully Ocean University, Busan, South Korea, 4Department of Environmental Engineering, Kongju National University, Chungnam, decomposed in brine solutions at 5 6 temperatures above 252 K, the South Korea, Beamline Department, Pohang Accelerator Laboratory, Pohang, South Korea, Department of Earth System 7 eutectic point of NaCl · 2H2O Sciences, Yonsei University, Seoul, South Korea, Western Seoul Center, Korea Basic Science Institute, Seoul, South Korea, 8Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, South Korea, 9Department of Chemistry and Nano-Science, College of Natural Sciences, Ewha Womans University, Seoul, South Korea Supporting Information: • Supporting Information S1 Abstract Understanding the stability of volatile species and their compounds under various surface and Correspondence to: J.-H.
    [Show full text]
  • 1 2.6 Physical Chemistry and Thermal Evolution of Ices at Ganymede 1 C
    1 1 2.6 Physical Chemistry and Thermal Evolution of Ices at Ganymede 2 C. Ahrens, NASA Goddard Space Flight Center, Greenbelt, MD; [email protected] 3 A. Solomonidou, Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA; & LEISA 4 – Observatoire de Paris, CNRS, UPMC Univ., Paris 06, Univ. Paris-Diderot, Meudon, France; 5 [email protected] 6 K. Stephan, Institute of Planetary Research, German Aerospace Center (DLR), Berlin, Germany; 7 [email protected] 8 K. Kalousova, Charles University, Faculty of Mathematics and Physics, Department of Geophysics, 9 Prague, Czech Republic; [email protected] 10 N. Ligier, Institut d’Astrophysique Spatiale, Université Paris-Saclay, Orsay, France; 11 [email protected] 12 T. McCord, Bear Fight Institute, Winthrop, WA; [email protected] 13 C. Hibbitts, Applied Physics Laboratory, Johns Hopkins University, Laurel, MD; 14 [email protected] 15 16 Abstract 17 18 Ganymede’s surface is composed mostly of water ice and other icy materials in addition to minor non-ice 19 components. The formation and evolution of Ganymede’s landforms highly depend on the nature of the 20 icy materials as they present various thermal and rheological behaviors. This chapter reviews the 21 currently known thermodynamic parameters of the ice phases and hydrates reported on Ganymede, which 22 seem to affect the evolution of the surface, using mainly results from the Voyager and Galileo missions. 23 24 Keywords: Ganymede; Ices; Ices, Mechanical Properties; Experimental techniques; Geological 25 processes 26 27 1 Introduction 28 29 Icy bodies of the outer solar system, including satellites of the gas giants, harbor surface ices made of 30 volatile molecules, clathrates, and complex molecules like hydrocarbons.
    [Show full text]
  • Ethane Clathrate Hydrate Infrared Signatures for Solar System Remote Sensing E Dartois, F Langlet
    Ethane clathrate hydrate infrared signatures for solar system remote sensing E Dartois, F Langlet To cite this version: E Dartois, F Langlet. Ethane clathrate hydrate infrared signatures for solar system remote sensing. Icarus, Elsevier, 2021. hal-03159998 HAL Id: hal-03159998 https://hal.archives-ouvertes.fr/hal-03159998 Submitted on 4 Mar 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Ethane clathrate hydrate infrared signatures for solar system remote sensing. E. Dartois1, F. Langlet2, 1 Institut des Sciences Moléculaires d’Orsay, CNRS, Université Paris-Saclay, Bât 520, Rue André Rivière, 91405 Orsay, France e-mail: [email protected] 2 Institut d’Astrophysique Spatiale (IAS), UMR8617, CNRS, Université Paris-Saclay, Bât. 121, 91405 Orsay, France keywords: Planetary ices, IR spectroscopy, Clathrate hydrate, Ethane, Remote sensing To appear in Icarus Abstract their retention time scales in solar system bodies, and also mod- ify their release conditions. b=The hydrate term is sometimes Hydrocarbons such as methane and ethane are present in many used as a semantic shortcut to designate clathrate hydrates but solar system objects, including comets, moons and planets. The must not be confused neither with hydrates nor with ice mixtures interaction of these hydrocarbons with water ice at low temper- where a molecule is interacting with water ice and not necessar- atures could lead to the formation of inclusion compounds, such ily mediated via an ordered crystalline cage.
    [Show full text]
  • Structural and Kinetic Studies of Structure I Gas Hydrates Via Low Temperature X-Ray Diffraction and High Resolution Neutron Diffraction
    University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2013 Structural and Kinetic Studies of Structure I Gas Hydrates via Low Temperature X-Ray Diffraction and High Resolution Neutron Diffraction Susan Michelle Everett [email protected] Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Other Materials Science and Engineering Commons Recommended Citation Everett, Susan Michelle, "Structural and Kinetic Studies of Structure I Gas Hydrates via Low Temperature X-Ray Diffraction and High Resolution Neutron Diffraction. " PhD diss., University of Tennessee, 2013. https://trace.tennessee.edu/utk_graddiss/1718 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Susan Michelle Everett entitled "Structural and Kinetic Studies of Structure I Gas Hydrates via Low Temperature X-Ray Diffraction and High Resolution Neutron Diffraction." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Materials Science and Engineering. Claudia
    [Show full text]
  • Thermodynamic Studies on CO2 Capture Through Gas Hydrate Formation Technology
    Thermodynamic Studies on CO2 Capture through Gas Hydrate Formation Technology Poorandokht Ilani-Kashkouli MSc. Analytical Chemistry (Shiraz University, Shiraz, Iran, (Sept2009-Jan2012)) This dissertation (ENNO8RPH1) is submitted for the degree of doctorate of philosophy in Engineering (Ph.D. Eng) in the School of Chemical Engineering at the University of KwaZulu- Natal. Supervisor: Prof. Deresh Ramjugernath Co-supervisor(s): Prof. Amir H. Mohammadi, Dr. Paramespri Naidoo April 2015 Declaration I, Poorandokht Ilani-Kashkouli, declare that: i. The research reported in this dissertation, except where otherwise indicated is my original work. ii. This dissertation has not been submitted for any degree or examination at any university. iii. This dissertation does not contain other person’s data, pictures, graphs or other information, unless specifically acknowledged as being sourced from other persons. iv. This dissertation does not contain other person’s writing, unless specifically acknowledged as being sourced from other researchers. Where other written sources have been quoted then: a) Their words have been re-written but the general information attributed to them has been referenced; b) Where their exact words have been used, their writing has been placed inside quotation marks, and referenced. v. Where I have reproduced a publication of which I am an author or co-author I have indicated in detail which part of the publication was actually written by myself alone and have fully referenced such publications. vi. This dissertation does not contain text, graphics or tables copied and pasted from the internet, unless specifically acknowledged, and the source are detailed in the dissertation and in the References sections.
    [Show full text]
  • Carbon Dioxide Clathrate Hydrate Formation at Low Temperature. Diffusion-Limited Kinetics Growth As Monitored by FTIR E
    Carbon dioxide clathrate hydrate formation at low temperature. Diffusion-limited kinetics growth as monitored by FTIR E. Dartois1, F. Langlet2, 1 Institut des Sciences Moléculaires d’Orsay, CNRS, Université Paris-Saclay, Bât 520, Rue André Rivière, 91405 Orsay, France e-mail: [email protected] 2 Institut d’Astrophysique Spatiale (IAS), UMR8617, CNRS, Université Paris-Saclay, Bât. 121, 91405 Orsay, France keywords: Infrared: planetary systems; Planets and satellites: composition; Comets: general; Methods: laboratory: solid state; Solid state: volatile; Molecular processes To appear in Astronomy & Astrophysics Abstract tion in climate change if natural fields are destabilised (Riboulot et al. 2018). Carbon dioxide clathrate hydrate is of interest for The formation and presence of clathrate hydrates could influ- fundamental research on Earth, or for its potential use in green- ence the composition and stability of planetary ices and comets; house gas sequestration (Duc et al. 2007; House et al. 2006). they are at the heart of the development of numerous complex planetary models, all of which include the necessary condition In a planetary or astrophysical context, clathrate hydrates imposed by their stability curves, some of which include the are considered because they can retain volatile molecules at cage occupancy or host-guest content and the hydration number, pressures higher than the pure compound that would otherwise but fewer take into account the kinetics aspects. We measure sublimate under most astrophysical conditions, and/or influence the temperature-dependent-diffusion-controlled formation of the the geophysics of large bodies (e.g. Fortes & Choukroun 2010; carbon dioxide clathrate hydrate in the 155-210 K range in or- Choukroun et al.
    [Show full text]
  • Planetary & Solar System Sciences
    EGU General Assembly 2012 EGU General Assembly 2012 Programme Group Programme PS – Planetary & Solar System Sciences Monday, 23 April ........................................................................................................................................................................ 2 PS1.1 ........................................................................................................................................................................................ 2 PS2.2 ........................................................................................................................................................................................ 2 GD1.1/PS2.7 .............................................................................................................................................................................. 3 PS3.3 ........................................................................................................................................................................................ 4 PS5.3/ST6.4 ............................................................................................................................................................................... 4 ST2.4/PS5.4 ............................................................................................................................................................................... 6 Tuesday, 24 April ......................................................................................................................................................................
    [Show full text]
  • Clathrate Desalination Plant, Preliminary Research Study
    CLATHRATE DESALINATION PLANT PRELIMINARY RESEARCH STUDY BY Richard A. McCormack Richard K. Andersen 8 Thermal Energy Storage, Inc. 6335 Ferris Square, Suite E San Diego, California 92121 Contract No. 1425-3-CR-81-19520 Water Treatment Technology Program Report No. 5 June 1995 U.S. DEPARTMENT OF THE INTERIOR Bureau of Reclamation Technical Service Center Water Treatment Engineering and Research Group Form Approved REPORT DOCUMENTATION PAGE Oh48 No. 0704-0188 0~15 Highway. SUW ‘X4. crlln9ton. V4 22202-4302. and 10 the OfWe 01 Management and Budget. Paperwork Reducteon PrOJecr (07040188). Washington, DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED 5. FUNDING NUMBERS CLATHRATE DESALINATION PLANT PRELIMINARY RESEARCH STUDY Contract No. 1425-3-CR-81-19520 6. AUTH%(S) Richard A. McCormack Richacd K. Andersen I : ! 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS Thermtil Energy Storage, Inc. 6335 Ferris Square, Suite E San Diego, CA 92121 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS 10. SPONSORlNG/MONlTORlNG AGENCY REPORT NUMBER Bureau of Reclamation Denver Federal Center Water Treatment PO Box 25007 Technology Program Denver, CO 80225-0007 Report No. 5 11. SUPPLEMENTARY NOTES t 12a. DISTRIBUTION /AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Available from the National Technical Information Service, I Operations Division, 5285 Port Royal Road, Springfield, 1 Virginia 22161 ! 1 t / t j 13. ABSTRACT (Maxrmvm 200 words) jThis report presents preliminary research, design, and cost estimates for a clathrate 1 ifreeze desalination method and system. A clathrate former is injected through the linner pipe of a submerged pipeline to a predetermined ocean depth at which the ocean itemperature is less than the clathrate forming temperature.
    [Show full text]
  • Experimental Study of Gas Hydrate Formation and Destabilisation Using a Novel High-Pressure Apparatus
    Marine and Petroleum Geology Archimer June 2010, Volume 27, Issue 6, Pages 1157-1165 http://archimer.ifremer.fr http://dx.doi.org/10.1016/j.marpetgeo.2010.03.002 © 2010 Elsevier Ltd All rights reserved. ailable on the publisher Web site Experimental study of gas hydrate formation and destabilisation using a novel high-pressure apparatus L. Ruffinea, *, J.P. Donvala, J.L. Charloua, A. Cremièrea and B.H. Zehnderb a IFREMER, Centre de Brest, Département de Géosciences Marines, 29280 Plouzané, France b SITEC-Sieber Engineering AG, Aschbach 621, CH – 8124 Maur, Switzerland *: Corresponding author : L. Ruffine, Tel.: +33 2 98 22 48 88; fax: +33 2 98 22 45 70, email address : [email protected] blisher-authenticated version is av Abstract: A novel variable-volume type high-pressure apparatus has been designed, constructed and used for gas hydrate investigations. The apparatus has an operating temperature ranging from 253 K to 473 K and pressure ranging from 0.1 MPa to 60 MPa. Its central component consists of a viewing windows cell to which several sensors or analytical instruments can be connected. At its present configuration, a Raman spectrometer and a gas chromatograph are connected for the study of the liquid (or solid) and the gas phases respectively. The apparatus was used for the study of two different systems. The first system was composed of carbon dioxide (CO2) and water for which the hydrate formation and dissolution has been investigated by injecting water into liquid CO2. The evolution of the system was monitored by means of visual observation in combination with Raman spectroscopy.
    [Show full text]
  • Rsc Cp C1cp21856e 1..8
    View Online / Journal Homepage / Table of Contents for this issue PCCP Dynamic Article Links Cite this: Phys. Chem. Chem. Phys., 2011, 13, 19765–19772 www.rsc.org/pccp PAPER Clathrate hydrate formation after CO2–H2O vapour deposition Christian Mitterdorfer,a Marion Bauerb and Thomas Loerting*a Received 8th June 2011, Accepted 8th September 2011 DOI: 10.1039/c1cp21856e We study vapour condensation of carbon dioxide and water at 77 K in a high-vacuum apparatus, transfer the sample to a piston-cylinder apparatus kept at 77 K and subsequently heat it at 20 MPa to 200 K. Samples are monitored by in situ volumetric experiments and after quench-recovery to 77 K and 1 bar by powder X-ray diffraction. At 77 K a heterogeneous mixture of amorphous solid water (ASW) and crystalline carbon dioxide is produced, both by co-deposition and sequential deposition of CO2 and H2O. This heterogeneous mixture transforms to a mixture of cubic structure I carbon dioxide clathrate and crystalline carbon dioxide in the temperature range 160–200 K at 20 MPa. However, no crystalline ice is detected. This is, to the best of our knowledge, the first report of CO2 clathrate hydrate formation from co-deposits of ASW and CO2. The presence of external CO2 vapour pressure in the annealing stage is not necessary for clathrate formation. The solid–solid transformation is accompanied by a density increase. Desorption of crystalline CO2 atop the ASW sample is inhibited by applying 20 MPa in a piston-cylinder apparatus, and ultimately the clathrate is stabilized inside layers of crystalline CO2 rather than in cubic or hexagonal ice.
    [Show full text]
  • Copyright © 2020 by Yutong Liu
    FACTORS AFFECTING GREENHOUSE GAS PRODUCTION AND ENRICHMENT OF NOVEL MICROORGANISMS FROM S1 BOG, MINNESOTA A Thesis Presented to The Academic Faculty By Yutong Liu In Partial Fulfillment of the Requirements for the Degree Master of Science in Civil and Environmental Engineering Georgia Institute of Technology May 2020 COPYRIGHT © 2020 BY YUTONG LIU FACTORS AFFECTING GREENHOUSE GAS PRODUCTION AND ENRICHMENT OF NOVEL MICROORGANISMS FROM S1 BOG, MINNESOTA Approved by: Dr. Joel Kostka, Co-Advisor School of biological Sciences Georgia Institute of Technology Dr. Spyros Pavlostathis, Co-Advisor School of Civil and Environmental Engineering Georgia Institute of Technology Dr. Joe Brown School of Civil and Environmental Engineering Georgia Institute of Technology Date Approved:04/23/2020 ACKNOWLEDGEMENTS First of all, I would like to thank my parents for supporting me and always encouraging me on my academic journey. Thank you so much for giving me umlimited love and care. I would like to regard this thesis article as a gift for your always support. Also, thank you for my relatives who supported me in many different ways, always in the deep of my heart. Much appreciation to my advisor, Dr. Joel Kostka. Thank you so much for providing me the excellent chance to work in your lab. You provided me the best academic environment you can; You always give me useful instructions when I have a difficult time and thank you for your patience and kindness. You care about me not only academically but also in my daily life. I really enjoy working and experiencing my Master’s journey with you. I would like to also thank my academic advisor, who is also my Master’s thesis co-advisor, Dr.
    [Show full text]
  • CO2 Storage in Novel CO2-H2O Phases at High Pressure
    CO2 Storage in Novel CO2-H2O Phases at High Pressure Benjamin Shih Montgomery Blair High School Under the guidance of: Dr. Ho-Kwang Mao, Dr. Chang-Sheng Zha Geophysical Laboratory, Carnegie Institute of Washington Washington DC Benjamin Shih An effective method for capturing and storing carbon dioxide in order to reduce atmospheric concentration is currently a research area of high interest. We investigated the potential of CO2 storage in H2O compounds by using optical Raman spectroscopy to analyze the high-pressure behavior of a CO2-H2O system in-situ. Between 26.9 and 1.0 GPa, we observed a new CO2-H2O compound whose vibrational spectra differed dramatically from pure CO2 and H2O. When pressure was decreased to <1 GPa, the CO2 vibrons and OH stretch reverted to those expected for pure CO2 and H2O respectively, indicating a CO2-H2O mixture rather than a CO2- H2O molecular compound. Based on the difference in spectra seen upon pressure cycling, as well as the difference in spectra seen at multiple locations inside the sample, we concluded that multiple forms of the CO2-H2O compounds may exist. Our results indicate that the initial structure and composition may play a role in compound formation. These novel materials have potential implications for increasing our understanding of CO2 interactions with potential host materials for improved CO2 storage applications. 2 Benjamin Shih INTRODUCTION The increasing amount of carbon dioxide in the atmosphere and its contribution to climate change is a serious global environmental concern. Significant efforts have been launched to develop an effective approach for capturing and storing carbon dioxide as a means of mitigating further damage to the environment.
    [Show full text]