THERMAL SCIENCE

International Scientific Journal

Tong-Qiang Xia

,

Jing-Yu Meng

,

You-Pai Wang

,

Jian-Hong Kang

,

Hong-Yun Ren

ROLES OF ADSORPTION POTENTIAL AND SURFACE FREE ENERGY ON PURE CH4 AND CO2 ADSORPTION UNDER DIFFERENT TEMPERATURES

ABSTRACT
To fill the knowledge of adsorption characteristics of CH4 and CO2 associated with equilibrium and thermodynamics, adsorption equilibrium tests of pure gas on a coal were conducted under the different temperatures (35 °C, 50 °C, and 65°C by the static volumetric method. The equilibrium data were well matched by the SLD-PR model. The influence of some significant factors including temperature, pressure, adsorption potential and surface free energy on gas adsorption capacity were discussed. The results showed that the higher temperature (gas pressure) corresponds to the smaller (larger) adsorption capacity and the larger adsorption potential is, the smaller adsorption capacity is. Taking CH4 as adsorbent, the modified Langmuir equation can well match the SLD-PR model. However, when the adsorption medium is CO2, modified Freundlich equation is better. Using the two modified equations, we study further the relationship among the variation of surface free energy, its reduction rate and gas adsorption capacity. It can be concluded the larger the gas adsorption capacity is, the greater the reduction of surface free energy is, and the smaller the reduction rate of surface free energy is.
KEYWORDS
gas adsorption, SLD-RP model, adsorption potential, surface free energy
PAPER SUBMITTED: 2018-06-05
PAPER REVISED: 2018-09-10
PAPER ACCEPTED: 2018-11-10
PUBLISHED ONLINE: 2019-03-31
DOI REFERENCE: https://doi.org/10.2298/TSCI180605089X
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2019, VOLUME 23, ISSUE Supplement 3, PAGES [S747 - S755]
REFERENCES
  1. Liu, J., et al., Interactions of Multiple Processes during CBM Extraction: a Critical Review. International Journal of Coal Geology, 87 (2011), 3-4, pp. 175-189.
  2. Xia, T. Q., Role of Thermodynamic Effect on Coal-gas Interactions during Underground Pre- and Post-mining Coal Seams in the Environmental Geology. Journal of Environmental Geology, 1(2017), Oct, 16, pp. 7-8.
  3. Xia, T. Q., et al., Fluid Flow in Unconventional Gas Reservoirs. Geofluids, 2018, pp. 1-2. doi.org/10.1155/2018/2178582
  4. Zhou F. D., et al., Injecting Pure N2 and CO2 to Coal for Enhanced Coalbed Methane Experimental Observations and Numerical Simulation. International Journal of Coal Geology, 116 (2013), pp. 53-62.
  5. Puri, R., et al., Enhanced Coalbed Methane Recovery. The 65th Annual Technical Conference and Exhibition of the Society of Petroleum Engineers, New Orieans, LA, Oct 5-8, 2019.
  6. Perera, M. S. A., et al., Estimation of Gas Adsorption Capacity in Coal: A Review and an Analytical Study, International Journal of Coal Preparation and Utilization, 32(2012), 1, pp. 25-55.
  7. Sudibandriyo, M., et al., Adsorption of Methane, Nitrogen, Carbon Dioxide and Their Binary Mixtures on Dry Activated Carbon at 318.2 K and Pressures to 13.6 MPa. Langmuir, 19(2003), 13, pp. 5323-5331
  8. Hall, F., et al., Adsorption of Pure Methane, Nitrogen, and Carbon Dioxide and Their Binary Mixtures on Wet Fruitland Coal. SPE Paper 29194, Charleston, SC; November,1994.
  9. Zhang, D. F., et al., Supercritical Pure Methane and CO2 Adsorption on Various Rank Coals of China: Experiments and Modeling. Energy & Fuels, 25(2011), 4, pp. 1891-1899.
  10. Crosdale, P. J., et al., Influence of Moisture Content and Temperature on Methane Adsorption Isotherm Analysis for Coals from a Low-rank, Biogenically-sourced Gas Reservoir. International Journal of Coal Geology, 76(2008), 1-2, pp. 166-174.
  11. Krooss, B. M., et al., High-pressure Methane and Carbon Dioxide Adsorption on Dry and Moisture-equilibrated Pennsylvanian Coals. International Journal of Coal Geology, 51(2002), 2, pp. 69-91
  12. Zhou, S. N., et al., Coalbed Methane Occurrence and Flow Theory. Beijing: Coal Industry Press, 1999.
  13. Charoensuppanimit, P., et al., Modeling the Temperature Dependence of Supercritical Gas Adsorption on Activated Carbons, Coals and Shales. International Journal of Coal Geology, 138(2015), pp. 113-126.
  14. Lama, R. D., et al., Management of Outburst in Underground Coal Mines. International Journal of Coal Geology, 35(1998), 1-4, pp.83-115.
  15. Rexer, T. F., et al., High-pressure Methane Adsorption and Characterization of Pores in Posidonia Shales and Isolated Kerogens. Energy & Fuels, 28(2014), 5, pp.2886-2901.
  16. Meysam, H., et al., Simplified Local Density Model for Adsorption of Pure Gases on Activated Carbon Using Sutherland and Kihara Potentials. Microporous and Mesoporous Materials, 136(2010), 1-3, pp. 1-9.
  17. Sayeed, A. M., et al., High-Pressure Adsorption of Pure Gases on Coals and Activated Carbon: Measurements and Modeling. Energy & Fuels, 26(2012), 1, pp. 536−548.
  18. Lee, L. L., Molecular Thermodynamics of Nonideal Fluids; Butterworth: Stoneham, MA, 1988.
  19. Fitzgerald, J. E., et al., Modeling High-Pressure Adsorption of Gas Mixtures on Activated Carbon and Coal Using a Simplified Local-Density Model. Langmuir, 22(2006), 23, pp. 9610−9618.
  20. Gasem, K. A. M., et al., A Modified Temperature Dependence for the Peng−Robinson Equation of State. Fluid Phase Equilibria, 181 (2001), 1-2, pp. 113−125.
  21. Robert, L., et al., Adsorption Characteristics of Coals Pyrolyzed at Slow Heating Rates. Energy & Fuels, 31(2017), 2, pp. 1803−1810.
  22. Zhao, W., et al., Modeling and Experiments for Transient Diffusion Coefficients in the Desorption of Methane Through Coal Powders. International Journal of Heat and Mass Transfer, 110(2017), Jul., pp. 845-854.
  23. Meng, Z. P., et al., Adsorption Capacity, Adsorption Potential and Surface Free Energy of Different Structure High Rank Coals. Journal of Petroleum Science and Engineering, 146(2016), Oct., pp. 856-865.
  24. Ramirez-Pastor, A. J., et al., Differential Heat of Adsorption in the Presence of an Order-disorder Phase Transition. Physica A, 283 (2000), 1-2, pp. 198-203.
  25. Jian, K., et al., The Surface Energy of Methane Adsorption of Tectonic Coal. Coal Geology & Exploration, 42 (2014), 1, pp. 31-39.
PDF VERSION [DOWNLOAD]
Roles of adsorption potential and surface free energy on pure CH4 and CO2 adsorption under different temperatures

© 2024 Society of Thermal Engineers of Serbia. Published by the Vinča Institute of Nuclear Sciences, National Institute of the Republic of Serbia, Belgrade, Serbia. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International licence