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Subcritical and Supercritical CO2 Adsorption Capacity of Post-UCG Gasified Coal
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- Author / Creator
- Zabihi, Sara
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Because of the increasing curiosity in the effectiveness of Underground Coal Gasification-Carbon Capturing and Storage (UCG-CCS) sites for carbon sequestration, an urge for a new line of research has emerged to measure the amount of CO2 adsorption in gasified coal as a potential long-term solution for global warming. In this study, the adsorption capacities of gasified coal from a UCG experiment is measured using a volumetric adsorption apparatus at 45.5 C and 500 Psia to 1500 Psia, and CO2 adsorption isotherms are obtained. This pressure range was chosen to cover both sub and super critical pressure regions of CO2. Additionally, the effect of the UCG process on surface area and pore volume development was investigated to correlate them to the adsorption capacity of the samples. The results indicate that the adsorption amount of the gasified coals increases as the pressure rises in the system, and continues to increase with a sharper slope after it passed the critical pressure of CO2. It was also observed that the surface area and pore volume of the samples increase more than two times during the gasification process, and up to 65 percent of the fixed carbon content in the samples converts to syngas. Samples farther from the ignition channel in UCG showed more conversion and structure transformation. The adsorption capacities of samples increased linearly with surface area and pore volume increments. The pore size distribution illustrated that pores with 1.5 nm in diameter contributed most effectively to the surface area of the samples. In addition, the SEM images of the gasified and raw coals validated the pore structure development due to the gasification.
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- Graduation date
- Spring 2017
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- Type of Item
- Thesis
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- Degree
- Master of Science
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- License
- This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.