| Scope and method of study. The Ono-Kondo (OK) lattice model was further developed to facilitate precise representations and accurate predictions for high-pressure, supercritical adsorption isotherms encountered in Coalbed Methane (CBM) recovery and CO2 sequestration. Specifically, the parameters of the OK model were regressed to obtain reliable representation of pure-gas, high-pressure adsorption on carbon adsorbents for adsorbates in the near-critical and supercritical regions. Following a thorough analysis, the OK model parameters were generalized, and the model was extended to mixture adsorption.; Systematically-selected measurements were conducted to supplement existing data on high-pressure adsorption. These data were used to support the model development. The measurements were conducted for pure methane, nitrogen, and CO2 and their mixture gas adsorption on an activated carbon and on selected coals at temperatures of 319 K and 328 K, and pressures to 13.8 MPa.; Findings and conclusions. The OK monolayer model appears effective in modeling pure-gas adsorption on carbon matrices at supercritical and near-critical regions. The model can represent adsorption on activated carbon and coals within their expected experimental uncertainties.; The generalized model, which relates the OK model parameters to gas properties and accessible adsorbent characterization, can predict the adsorption isotherms on activated carbon with about 7% average absolute deviation or twice the expected experimental uncertainties. The generalized model can also predict the adsorption isotherms of various gases based on the adsorption isotherm of one gas on the same adsorbent. In addition, the generalized model appears effective in modeling pure-gas adsorption on wet coals when the coal moisture content is above its equilibrium value. However, the model parameter values in this case are affected by the presence of water.; The OK model is capable of predicting binary and ternary gas adsorption within twice the experimental uncertainties, on average. Further, the total and individual component adsorption can be represented to within the expected experimental uncertainties with the use of one binary interaction parameter. |
