Permeability changes in coal resulting from gas desorption
The goal of this task is to accurately measure the elongation and shrinkage exhibited by coal as it sorbs and desorbs methane gas at elevated pressure. Our research group has discussed several possible methods to measure this strain, including: optical microscopy, laser interferometry, conventional strain gauges, and LVDT strain gauges. There are advantages and disadvantages of each method. We had planned to use optical microscopy but, on further investigation, this approach will be less satisfactory than the strain gauge method. Accordingly, we have switched our focws to the use of strain gauges. Conventional strain gauges also involve potential problems which must be overcome, including: (1) Contrast in strength between the coal and the strain gauge must be minimized, (2) The proper glue that is neither too strong or too weak must be used to affix the strain gauge to the coal or the strain in the coal will not be accurately transmitted to the gauge, and (3) We must be aware that the total strain in the coal may not be homogeneously distributed through the specimen (due either either to boundary effects or contrast in composition of the coal layers). A high pressure chamber for sorption-strain experiments is currently being tested an modified and tested. The chamber will accommodate several small blocks of coal simultaneously. This will optimize efficiency, owing to the long times required to reequilibrate the coal blocks to changes in methane pressure.
- Research Organization:
- Alabama Univ., University, AL (United States)
- Sponsoring Organization:
- USDOE; USDOE, Washington, DC (United States)
- DOE Contract Number:
- FG22-89PC89764
- OSTI ID:
- 6995047
- Report Number(s):
- DOE/PC/89764-T9; ON: DE92041296
- Country of Publication:
- United States
- Language:
- English
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Permeability changes in coal resulting from gas desorption
Shrinkage and Swelling of Coal Induced by Desorption and Sorption of Fluids: Theoretical Model and Interpretation of a Field Project
Related Subjects
COAL
SHRINKAGE
SORPTIVE PROPERTIES
SWELLING
METHANE
ADSORPTION
DESORPTION
NUMERICAL DATA
PERMEABILITY
PROGRESS REPORT
STRAIN GAGES
ALKANES
CARBONACEOUS MATERIALS
DATA
DOCUMENT TYPES
ENERGY SOURCES
FOSSIL FUELS
FUELS
HYDROCARBONS
INFORMATION
MATERIALS
MEASURING INSTRUMENTS
ORGANIC COMPOUNDS
SORPTION
SURFACE PROPERTIES
010600* - Coal
Lignite
& Peat- Properties & Composition