Validation of Using a Modified BET Model to Predict the Moisture Adsorption Behavior of Bituminous Coal

Strydom, Christien A.; Campbell, Q.P.; Roux, M. Le; Preez, S.M. Du

doi:10.1080/19392699.2015.1049264

Cited by 18 publications

(14 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, the H 2 O uptake of the coals obeys the sequence of SCG > SH > DQ. Such an order agrees with the order of development degree of the coal mesopore, demonstrating that the mesopore of coal is the main space for H 2 O occurrence . Particularly, at high P / P s above 0.60 (stages 3–4), H 2 O molecules can form clusters and eventually be stored via filling in micropores and capillary condensation in mesopores .…”

Section: Resultssupporting

confidence: 71%

“…Moreover, the adsorption potential energy ( E ) of primary adsorption and secondary adsorption can be calculated from K 1 and K 2 , respectively, where E L is the latent heat of H 2 O liquefaction at T = 303.15 K, that is, 43.74 kJ/mol.…”

Section: Modelingmentioning

confidence: 99%

“…The original BET model fails to address H 2 O adsorption equilibrium on coal due to the fact that it ignores the heterogeneity in pore structure and surface chemistry of the coal matrix. 49 Instead, it is necessary to take dual adsorption sites into account to well explore H 2 O adsorption equilibrium on coal. Based on this, the modified BET model with good predictive accuracy was adopted to fit the H 2 O adsorption isotherms of the coals.…”

Section: Modelingmentioning

confidence: 99%

See 2 more Smart Citations

Influence of H₂O on Adsorbed CH₄ on Coal Displaced by CO₂ Injection: Implication for CO₂ Sequestration in Coal Seam with Enhanced CH₄ Recovery (CO₂-ECBM)

Liu

Wang

Lun

et al. 2021

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

CO 2 -ECBM is capable of realizing CO 2 sequestration and coalbed methane (CH 4 ) production simultaneously. Practical coal seam contains H 2 O, thus significantly influencing adsorption, desorption, diffusion, and flow capability of CO 2 and CH 4 . Accordingly, the impacts of H 2 O on adsorbed CH 4 on coal displaced by CO 2 were investigated to gain a further understanding on CO 2 -ECBM. The results derived from this study indicate that the occurrence of H 2 O with coal positively relates to oxygenic functional groups and mesopores of coal. Particularly, the oxygenic functional group of the coal matrix acts as a primary adsorption site for H 2 O. The mesopore of coal is the main space for H 2 O occurrence. Furthermore, the impact of H 2 O on CO 2 adsorption on coal depends on dissolution capability and competitive adsorption of H 2 O. With respect to coal with a low H 2 O content, the dissolution of CO 2 in H 2 O is dominant at high CO 2 adsorption equilibrium pressure, thus leading to increasing CO 2 adsorption capability of coal, while the opposite trend is applicable for coal with a high H 2 O content. With regard to the displacement process, injecting CO 2 promotes desorption of adsorbed CH 4 from dry and moist-equilibrated coals. The absolute adsorption amount of CO 2 at the equilibrium state for displacement is lower than that in single-component adsorption for both dry and moisture-equilibrated coals at equilibrium pressures below 3 MPa, whereas the adverse trend exists for a high equilibrium pressure range of 3−4 MPa. Moreover, the elevated CO 2 injection pressure favors both CO 2 adsorption and CH 4 desorption on dry and moisture-equilibrated coals. The presence of H 2 O decreases the CO 2 adsorption amount and CH 4 desorption amount of the coals. Therefore, practical implementation of CO 2 -ECBM should focus on the H 2 O dependence of CO 2 sequestration and CH 4 recovery.

show abstract

Section: Resultssupporting

confidence: 71%

Section: Modelingmentioning

confidence: 99%

Section: Modelingmentioning

confidence: 99%

See 1 more Smart Citation

Influence of H₂O on Adsorbed CH₄ on Coal Displaced by CO₂ Injection: Implication for CO₂ Sequestration in Coal Seam with Enhanced CH₄ Recovery (CO₂-ECBM)

Liu

Wang

Lun

et al. 2021

Ind. Eng. Chem. Res.

View full text Add to dashboard Cite

show abstract

“…To ensure that feedstocks adhere to these specifications, coal are washed using mainly wet dense medium processes. These processes are known to produce low ash products at high yields; however, it is water intensive and ends up with a wet product that is costly and difficult to dewater (Strydom et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Dry beneficiation of +0.5mm-5.6mm South African coal using an air dense medium fluidization bed

Diedericks¹,

Roux²,

Campbell³

2021

Preprint

View full text Add to dashboard Cite

The separation performance of solid phase bed material, at various particle size ranges, in an air dense medium fluidized bed (ADMFB), were evaluated during this study. The coal particles were separated into +0.5mm-1mm, +1mm-2mm, +2mm-2.8mm, +2.8mm-4mm, +4mm-4.75mm and +4.75mm-5.6mm particle size ranges and fed to the fluidized bed in these fractions. Along with the six coal particle size ranges, three dense media to coal ratios and the addition of vibration was tested to identify the best operating conditions. Adequate results were obtained for larger particle size ranges down to and including +2.0mm-2.8mm coal particles, after which the separation performance decreased significantly. Density stratification was irregular and not obvious for coal particles below 2.0mm and maintaining a consistent fluidization state also proved to be challenging, especially when dense medium was added. The coal particles separated vertically along the bed height because of differences in particle and bed density, while particle size proved to have a notable influence on the degree of separation. An air fluidization velocity of between 1.1 to 1.4Umf was shown as the best performing velocity, which yielded the maximum ash differential between the top and bottom layers of the bed for all the particle size ranges tested. For +2.0mm-5.6mm coal particles, low cumulative ash yields were obtained at high mass yields, however the ash yields increased for -2mm coal. Vibration and dense medium have, in some cases, enhanced the separation efficiency of the ADMFB. The -2.0mm particles experienced stronger particle-particle interactions as well as elevated levels of bubbling and back mixing than that of the +2.0mm particles, which explains the poor performance of the small particle sizes.

show abstract

“…The result provides an experimental basis for the selection of methane-adsorbing materials and carrying out "solid-gas" coupling physical simulation experiments in a physically similar testing model.Many researchers [5][6][7] and other experiments through the methane adsorption of coal containing several different particle sizes concluded that the methane adsorption amount increases as the coal particle size decreases within a certain range. Some researchers [8][9][10][11][12][13] used the artificial humidification method to study the methane adsorption principle of coal samples under different moisture contents. Their findings showed that the rate of methane adsorption decreased with the increase of moisture content based on the microscopic mechanism.…”

mentioning

confidence: 99%

Evaluating Methane Adsorption Characteristics of Coal-Like Materials

Zhao

Liu

et al. 2020

Materials

View full text Add to dashboard Cite

In order to investigate the methane adsorption characteristics of coal seam materials in a “solid–gas” coupling physical simulation experiment, activated alumina, silica gel, the 3Å molecular sieve, 4Å molecular sieve and 5Å molecular sieve were selected as adsorption materials. According to the pore structure and adsorption characteristics, coal samples at the Aiweiergou #1890 working face were prepared as compared materials. The WY-98A methane adsorption coefficient measuring instrument was used to carry out this adsorption experiment under different temperatures, particle sizes and moisture contents. The results suggested that the adsorption principles of three kinds of molecular sieves under multiple factors do not fully fit a Langmuir adsorption model, and cannot be used as adsorption materials. The changing trend of the adsorption increment of activated alumina and silica gel are similar to that of coal samples, so they can be used as a coal-like materials. The methane adsorption coefficient a value changing trends of activated alumina and silica gel appear to be the same as the Aiweiergou #1890 coal samples, but the results from silica gel are closer to that of coal samples. Thus, silica gel is preferred as the adsorption material. The result provides an experimental basis for the selection of methane-adsorbing materials and carrying out “solid–gas” coupling physical simulation experiments in a physically similar testing model.

show abstract

Validation of Using a Modified BET Model to Predict the Moisture Adsorption Behavior of Bituminous Coal

Cited by 18 publications

References 16 publications

Influence of H₂O on Adsorbed CH₄ on Coal Displaced by CO₂ Injection: Implication for CO₂ Sequestration in Coal Seam with Enhanced CH₄ Recovery (CO₂-ECBM)

Influence of H₂O on Adsorbed CH₄ on Coal Displaced by CO₂ Injection: Implication for CO₂ Sequestration in Coal Seam with Enhanced CH₄ Recovery (CO₂-ECBM)

Dry beneficiation of +0.5mm-5.6mm South African coal using an air dense medium fluidization bed

Evaluating Methane Adsorption Characteristics of Coal-Like Materials

Contact Info

Product

Resources

About

Validation of Using a Modified BET Model to Predict the Moisture Adsorption Behavior of Bituminous Coal

Cited by 18 publications

References 16 publications

Influence of H2O on Adsorbed CH4 on Coal Displaced by CO2 Injection: Implication for CO2 Sequestration in Coal Seam with Enhanced CH4 Recovery (CO2-ECBM)

Influence of H2O on Adsorbed CH4 on Coal Displaced by CO2 Injection: Implication for CO2 Sequestration in Coal Seam with Enhanced CH4 Recovery (CO2-ECBM)

Dry beneficiation of +0.5mm-5.6mm South African coal using an air dense medium fluidization bed

Evaluating Methane Adsorption Characteristics of Coal-Like Materials

Contact Info

Product

Resources

About

Influence of H₂O on Adsorbed CH₄ on Coal Displaced by CO₂ Injection: Implication for CO₂ Sequestration in Coal Seam with Enhanced CH₄ Recovery (CO₂-ECBM)

Influence of H₂O on Adsorbed CH₄ on Coal Displaced by CO₂ Injection: Implication for CO₂ Sequestration in Coal Seam with Enhanced CH₄ Recovery (CO₂-ECBM)