Studying the removal of CO2 on stratified ZnO prepared by hydro

In this study, ZnO was synthesized by the simple hydrothermal method. The physicochemical properties of the materials were characterized by SEM, XRD, N adsorption/desorption isotherm methods. The CO2 removal experiments were conducted using the thermogravimetric method (TGA). The material has a stratified structure, with a surface area of 24.4 m2/g and a pore volume of 0.280 cm3/g. The influences of temperature, ZnO morphology, and feed gas composition were studied. Besides, the durability and applicability of the material were evaluated through repeated regeneration.

Elucidating the structure, redox properties and active entities of high-temperature thermal aged CuOx-CeO2 catalysts for CO-PROX

CuOx-CeO2 catalysts with different copper content are synthesized via a coprecipitation method and thermal treated at 700 oC. Various characterization techniques including X-ray diffraction (XRD) Rietveld refinement, N2 adsorption-desorption isotherm,...

Volumetric Measurements of Methane-Coal Adsorption and Desorption Isotherms—Effects of Equations of State and Implication for Initial Gas Reserves

This study presents the effects of equations of state (EOSs) on methane adsorption capacity, sorption hysteresis and initial gas reserves of a medium volatile bituminous coal. The sorption experiments were performed, at temperatures of 25 °C and 40 °C and up to 7MPa pressure, using a high-pressure volumetric analyzer (HPVA-II). The measured isotherms were parameterized with the modified (three-parameter) Langmuir model. Gas compressibility factors were calculated using six popular equations of state and the results were compared with those obtained using gas compressibility factors from NIST-Refprop® (which implies McCarty and Arp’s EOS for Z-factor of helium and Setzmann and Wagner’s EOS for that of methane). Significant variations were observed in the resulting isotherms and associated model parameters with EOS. Negligible hysteresis was observed with NIST-refprop at both experimental temperatures, with the desorption isotherm being slightly lower than the adsorption isotherm at 25 °C. Compared to NIST-refprop, it was observed that equations of state that gave lower values of Z-factor for methane resulted in “positive hysteresis”, (one in which the desorption isotherm is above the corresponding adsorption curve) and the more negatively deviated the Z-factors are, the bigger the observed hysteresis loop. Conversely, equations of state that gave positively deviated Z-factors of methane relatively produced “negative hysteresis” loops where the desorption isotherms are lower than the corresponding adsorption isotherms. Adsorbed gas accounted for over 90% of the calculated original gas in place (OGIP) and the larger the Langmuir volume, the larger the proportion of OGIP that was adsorbed.