Study of interfacial properties in the liquid carbon dioxide-water-coal system

Abstract

evolution strongly depends on gas adsorption conditions, and we still do not know the exact correspondence between the gas desorption site and the gasification site. Further work is required to clarify this point. ConclusionsTPD patterns of H20-gasified and 02-chemisorhed chars from various types of coals showed some sharp desorption peaks and/or broad desorptions. The appearance of a sharp peak depends on whether the sample contains catalytically active mineral matter or not. The gasification mechanism for the formation of the sharp peak was closely associated with the mechanism for the gasification reaction catalyzed by mineral matter. The broad desorption patterns were common for both raw and demineralized chars, and they were very similar among various chars. There-fore, this desorption emanates from the carbon substrate itself. The effect of the char type on the formation of surface oxygen complex is not so significant. The TPD experiments on chars prepared under different adsorption conditions (as in H20-gasified and 02-chemisorbed chars) revealed different kinds of useful information on the surface oxygen-containing complexes.Acknowledgment. This work was supported in part by a Grant-in-Aid for Scientific Research from the Ministry of Education, Science and Culture, Japan, Special Project for Energy (No. 60040034). Acknowledgment is also made to the donors of the Petroleum Research Fund, administered by the American Chemical Society, for partial support of this activity.Registry No. H20, C02,

CO2 geological storage — Geotechnical implications

“…Furthermore, the contact angle formed by the CO 2 -water interface on mineral surfaces varies with fluid pressure in response to changes in CO 2 -water interfacial tension: as the fluid pressure increases, the contact angle increases on non-wetting surfaces such as oil-wet quartz and coal and slightly decreases in water-wet quartz and calcite surfaces (Chalbaud et al, 2009;Chi et al, 1988;Chiquet et al, 2007;Dickson et al, 2006;Espinoza and Santamarina, 2010).…”

Effect of coal petrology and pressure on wetting properties of wet coal for CO2 and flue gas storage

“…Keller (1987) summarized literature data (Fuerstenau and Diao, 1992;Murata, 1981) on surface properties of coal-water-air systems. Chi et al (1988) found that the contact angle in a CO 2 -water-coal system increases with pressure in the range from atmospheric up to 6.2 MPa. Additionally, it was observed that when the ash content increases, the coal becomes more water wet.…”

The Effect of Coal Rank on the Wettability Behavior of Wet Coal System with Injection of Carbon Dioxide and Flue Gas

“…However, only a few experimental data on the wettability at high pressures and elevated temperatures exist, particularly in the presence of flue gas (Shojai Kaveh et al, 2011;Siemons, 2007;Chi et al, 1987). From the data of Siemons it can be concluded that for highrank coal wetting alteration from water-wet to CO 2 -wet occurs at a pressure as low as 0.27 MPa.…”