CO2 hydrate formation and dissociation rates: Application to Mars

Ambuehl, Dan; Madden, M. E. Elwood

doi:10.1016/j.icarus.2014.01.037

Cited by 19 publications

(24 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hydrate-bound gas contains both hydrocarbons and CO 2 [ 5 , 6 , 7 ], and natural gas hydrates encapsulating CO 2 have been observed at the venting sites of liquid CO 2 [ 8 , 9 ]. On the other hand, the possibility of existing CO 2 hydrates on Mars was proposed [ 10 , 11 ] and the conditions for CO 2 hydrate formation on Mars have been discussed [ 12 ]. As above, CO 2 hydrates are critical in both geochemistry and space science and require better understanding.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

View full text Add to dashboard Cite

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 CO2 hydrate formation and measured the three-phase equilibria of 12CO2–H2O and 13CO2–H2O systems. From a crystal structure viewpoint, the difference in the Raman spectra of hydrate-bound 12CO2 and 13CO2 was revealed, although their unit cell size was similar. The δ13C 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 ~0.01 MPa in 12CO2 and 13CO2 hydrates causes carbon isotope fractionation of ~1‰. However, the difference between equilibrium pressures in the 12CO2–H2O and 13CO2–H2O systems was smaller than the standard uncertainties of measurement; more accurate pressure measurement is required for quantitative discussion.

show abstract

Section: Introductionmentioning

confidence: 99%

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

et al. 2021

View full text Add to dashboard Cite

show abstract

“…However, the low pressure sI phase of the CO 2 hydrate has not received enough attention in the past in contrast with the number of experimental and theoretical studies on methane hydrate clathrates [ 9 ]. In recent years, new studies have tried to characterize and interpret its high pressure behavior [ 6 , 10 ] and the kinetics of its formation [ 11 , 12 ]. The ability of the two water cage types in the cubic sI phase to host a CO 2 molecule has been thoroughly examined by Srivastava and Sastry [ 13 ] using cluster models.…”

Section: Introductionmentioning

confidence: 99%

Effects of the CO2 Guest Molecule on the sI Clathrate Hydrate Structure

et al. 2016

View full text Add to dashboard Cite

This paper analyzes the structural, energetic and mechanical properties of carbon dioxide hydrate clathrates calculated using finite cluster and periodic ab initio density-functional theory methodologies. Intermolecular interactions are described by the exchange-hole dipole moment method. The stability, gas saturation energetics, guest–host interactions, cage deformations, vibrational frequencies, and equation of state parameters for the low-pressure sI cubic phase of the CO2@H2O clathrate hydrate are presented. Our results reveal that: (i) the gas saturation process energetically favors complete filling; (ii) carbon dioxide molecules prefer to occupy the larger of the two cages in the sI structure; (iii) blue shifts occur in both the symmetric and antisymmetric stretching frequencies of CO2 upon encapsulation; and (iv) free rotation of guest molecules is restricted to a plane parallel to the hexagonal faces of the large cages. In addition, we calculate the librational frequency of the hindered rotation of the guest molecule in the plane perpendicular to the hexagonal faces. Our calculated spectroscopic data can be used as signatures for the detection of clathrate hydrates in planetary environments.

show abstract

“…CO 2 hydrate may also be related to Martian environment. On Mars, CO 2 hydrate may naturally occur in ice caps and/or permafrost [9,14]. CO 2 hydrate on Martian surface is estimated to be stable during the winter, at approximate 150 K, and unstable during the summer, at approximate 250 K [15].…”

Section: Introductionmentioning

confidence: 99%