HR: 1340h
AN: H13F-1657    [Abstracts]
TI: Differential Absorption Measurements of Carbon Dioxide for Carbon Sequestration Site Monitoring Using a Temperature Tunable Diode Laser
AU: * Humphries, S D
EM: seth.humphries@myportal.montana.edu
AF: Montana State University Department of Electrical and Computer Engineering, Cobleigh 610, Bozeman, MT 59717, United States
AU: Nehrir, A R
EM: amin.nehrir@myportal.montana.edu
AF: Montana State University Department of Electrical and Computer Engineering, Cobleigh 610, Bozeman, MT 59717, United States
AU: Repasky, K S
EM: repasky@ece.montana.edu
AF: Montana State University Department of Electrical and Computer Engineering, Cobleigh 610, Bozeman, MT 59717, United States
AU: Carlsten, J L
EM: carlsten@physics.montana.edu
AF: Montana State University Department of Physics, EPS 264, Bozeman, MT 59717, United States
AU: Spangler, L H
EM: spangler@montana.edu
AF: Montana State University Department of Chemistry, Gaines Hall 3400, Bozeman, MT 59717, United States
AU: Dobeck, L M
EM: dobeck@chemistry.montana.edu
AF: Montana State University Department of Chemistry, Gaines Hall 3400, Bozeman, MT 59717, United States
AU: Shaw, J A
EM: jshaw@ece.montana.edu
AF: Montana State University Department of Electrical and Computer Engineering, Cobleigh 610, Bozeman, MT 59717, United States
AB: Carbon capture and sequestration in geologic formations provides a method to remove carbon dioxide (CO2) from entering the Earth's atmosphere. An important issue for the successful storage of CO2 is the ability to monitor geologic sequestration sites for leakage to verify site integrity. A differential absorption measurement instrument based on a continuous wave (cw) temperature tunable distributed feedback (DFB) laser has been developed for measuring atmospheric concentrations of CO2. The tunable DFB laser is capable of tuning across two CO2 absorption features at 2003.50 nm and 2004.02 nm. The measured normalized transmission through the atmosphere is then related to the atmospheric concentration of CO2 through the line strength and normalized line width associated with each absorption feature. A description of this instrument will be presented including the instrument design, operation, and performance characteristics. A field site for testing the performance of CO2 detection instruments and techniques has been developed by the Zero Emissions Research Technology (ZERT) group at Montana State University. The field site allows a controlled flow rate of CO2 to be released underground through a 100 m long horizontal pipe placed below the water table. Two release experiments were performed this past summer with flow rates of 0.1 and 0.3 tons CO2/day. The first release experiment lasted ten days while the second release lasted seven days. Measurements taken with the differential absorption instrument over the horizontal well during these release experiments showed an increase of greater than 300 parts per million (ppm) over the background CO2 concentration. These results indicate the capabilities of the above ground differential absorption instrument for carbon sequestration site monitoring.
DE: 0480 Remote sensing
DE: 0649 Optics (4264)
DE: 3934 Optical, infrared, and Raman spectroscopy
SC: Hydrology [H]
MN: 2007 Fall Meeting