Carbon Dioxide Adsorption in Brazilian Coals
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- 作者：José ; Luciano Soares ; André ; L. B. Oberziner ; Humberto J. José ; Alí ; rio E. Rodrigues ; Regina F. P. M. Moreira
- 刊名：Energy & Fuels
- 出版年：2007
- 出版时间：January 2007
- 年：2007
- 卷：21
- 期：1
- 页码：209 - 215
- 全文大小：134K
- 年卷期：v.21,no.1(January 2007)
- ISSN：1520-5029
文摘
Carbon dioxide (CO2) is one of the most important greenhouse gases. In the period between 1980 and 1998,CO2 emissions increased more than 21% and projections suggest that the emissions will continue to increaseglobally by 2.2% between 2000 and 2020 and 3.3% in the developed countries. The sequestration of CO2 indeep unminable coal beds is one of the more promising of several methods of geological sequestration that arecurrently being investigated. CO2 can adsorb onto coal, and there are several studies demonstrating that CO2dissolves in coals and swells them. At very low pressures (P < 1 bar), CO2 dissolution does not seem to bea problem; however, high pressures are necessary for CO2 sequestration (P > 50 bar). In this study, we evaluatedthe kinetics and equilibrium of sorption of CO2 on Brazilian coals at low pressures. The adsorption equilibriumisotherm at room temperature (30 
f">C) was measured through the static method. The results showed that theFreundlich model or the Langmuir model is suitable to describe the equilibrium experimental results. TheCO2 adsorption capacity of Brazilian coals are in the range of 0.089-0.186 mmol CO2/g, which are typicalvalues for coals with high ash content. The dynamics of adsorption in a fixed-bed column that contains granularcoal (particle sizes of 0.8, 2.4, and 4.8 mm) showed that the adsorption rate is fast and a mathematical modelwas developed to describe the CO2 dynamics of the adsorption in a fixed-bed column. The linear driving force(LDF) was used to describe the rate of adsorption and the mass-transfer constants of the LDF model (Ks) arein the range of 1.0-2.0 min-1.
f">C) was measured through the static method. The results showed that theFreundlich model or the Langmuir model is suitable to describe the equilibrium experimental results. TheCO2 adsorption capacity of Brazilian coals are in the range of 0.089-0.186 mmol CO2/g, which are typicalvalues for coals with high ash content. The dynamics of adsorption in a fixed-bed column that contains granularcoal (particle sizes of 0.8, 2.4, and 4.8 mm) showed that the adsorption rate is fast and a mathematical modelwas developed to describe the CO2 dynamics of the adsorption in a fixed-bed column. The linear driving force(LDF) was used to describe the rate of adsorption and the mass-transfer constants of the LDF model (Ks) arein the range of 1.0-2.0 min-1.