Moisture Retention and Multi-Mechanistic Transport Behavior in Nanoporous Coal

Details

• Personal Author:
  Liu A ; Liu S ; Wang K
• Description:
  Coal-water interactions induced by water retention in coals control the performance of coalbed methane reservoirs and coal utilizations. Experimental measurements on Illinois coal samples using X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, low-temperature N2 adsorption, low-pressure CO2 adsorption, and dynamic water vapor sorption were carried out. A mechanism-based isothermal model of water vapor sorption was proposed to estimate the water adsorption capacity at varied relative humidity, which implicitly considered both monolayer and multilayer adsorptions and capillary condensation. The analytical models for quantifying the stage-based diffusion coefficients as well as the apparent diffusion coefficients at different relative humidities were proposed and well validated. The contributions of different diffusion regimes to the total mass flow were discussed. At the first stage, both free water vapor diffusion and surface diffusion of adsorbed water molecules contribute to the total mass flow whereas the apparent diffusion at this stage is dominated by latter flow regime; during the second stage, the contribution of free water vapor flow to the apparent flow can be neglected and the mass transfer at this stage is still dominated by the surface diffusion flow; upon reaching the critical relative humidity, the flow in capillary condensation will dominate the total mass flow. [Description provided by NIOSH]
• Subjects:
  Coal Coal Mining Environment Humidity Mining Occupational Health Safety Solvents
• Keywords:
  Adsorption Coal Mining Environmental Factors Underground Mining Vapors
• ISSN:
  0743-7463
• Document Type:
  Text
• Funding:
  Contract
• Genre:
  Journal Article
• Place as Subject:
  OSHA Region 3 ; Pennsylvania
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  38
• Issue:
  48
• NIOSHTIC Number:
  nn:20067789
• Citation:
  Langmuir 2022 Dec; 38(48):14941-14958
• Contact Point Address:
  Shimin Liu, Department of Energy and Mineral Engineering, G Center and Energy Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, United States
• Email:
  szl3@psu.edu
• Federal Fiscal Year:
  2023
• Performing Organization:
  Pennsylvania State University
• Peer Reviewed:
  True
• Start Date:
  20190827
• Source Full Name:
  Langmuir
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:63c345fec2d2eb8c5a39fabac6adee83c6026fdd89ca9562d617ea6acc2de8bc61c12e502cc4e46a4d8070034c82b3acfcd8143eab03e9dcc426597059605a34
• Download URL:
  https://stacks.cdc.gov/view/cdc/230045/cdc_230045_DS1.pdf
• File Type:
  [PDF - 5.14 MB ]