Mert Atilhan

Molecular Modeling Analysis of CO2 Absorption by Glymes

The properties of diglyme + CO2 systems were analyzed through density functional theory and molecular dynamics methods with the objective of inferring the microscopic properties of CO2 capture by glyme-based solvents and the effect of ether group regarding solvents affinity toward CO2. Calculations of diglyme + CO2 molecular clusters using density functional theory allowed accurate quantification and characterization of short-range intermolecular forces between these molecules, whereas the molecular dynamics simulation of diglyme + CO2 liquid mixtures, for different CO2 contents, were the means to infer the properties and dynamics of bulk liquid phases upon CO2 absorption. Likewise, liquid diglyme + CO2 gas interfaces were also studied using molecular dynamics methods to examine the kinetics of CO2 capture, adsorption at the gas-liquid interface, and the mechanism of interface crossing, which is of pivotal importance for the design of CO2 capturing units.

Review on Natural Gas Thermopysical Property Measurement Techniques

Since it is impossible to measure the thermodynamics properties of all systems in nature, we must rely upon mathematical models to extrapolate the available experimental data. In order to develop such models, very accurate experimental data are necessary for selected complex mixtures, such as those that exist in natural gas. For this reason researchers must collect the most important and fundamental thermodynamics properties for such systems. Two of the most important thermodynamics properties are the pressure volume (density) and temperature (PT) surface and the phase equilibrium properties of mixtures. Accurate volumetric property data are used in custody transfer operations for natural gas. Also accurate PT data are necessary for calculating energy functions. On the other hand, phase equilibria data are needed mostly for design calculations involving separation processes. Additionally, very accurate phase equilibrium knowledge is necessary for natural gas transfer through pipelines to avoid condensation in the pipelines. Atilhan et. al. [1] have shown that even widely used equations of state (EOS) such as Peng-Robinson or RedlichKwong (RK) cannot predict the retrograde condensation region for simple natural gas-like mixtures that do not contain heavy fractions.

High-pressure CO2 Adsorption on Conventional Hydroxyl Metal Carbonates

Abstract Carbon dioxide (CO2) adsorption capacities of several hydroxy metal carbonates have been studied using the state-of-the-art RubothermR Sorption apparatus to obtain adsorption and desorption isotherms of these compounds up to 175 bar. The carbonate compounds were prepared by simply reacting a carbonate (CO32−) solution with solutions of Zn2+, Zn2+/Mg2+, Mg2+, Cu2+/Mg2+, Cu2+, Pb2+, and Ni2+ metal ions resulting in hydroxyzincite, hydromagnesite, mcguinnessite, malachite, nullaginite, and hydrocerussite, respectively. Mineral compositions are calculated by using a combination of powder XRD, TGA, FTIR, and ICP-OES analysis. Adsorption capacity of hydroxy nickel carbonate compound obtained from RubothermR Magnetic Suspension Sorption apparatus has shown highest performance among the other components that were investigated in this work (1.72 mmole CO2/gram adsorbent at 175 bar and 316 K).

Preparation, characterization and investigation of CO2 adsorption behavior of zinc-magnesium carbonate compounds

AbstractThe capture of CO2 from flue gases derived from fossil fuelled power plants and the absorption of CO2 from natural gas sweetening processes are two relevant industrial problems closely related with very important environmental, economical and technological problems that need to be solved. Porous inorganic compounds have received attention in recent years due to their possible applications in the carbon dioxide capture and storage field. In this work, we prepared new metal carbonates by reacting CO32- solution with solutions of Zn2+-Mg2+ metal ions in different stoichiometric ratios. The samples were characterized with powder x-ray diffraction analysis (PXRD), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Furthermore, these samples were measured with a Rubotherm magnetic suspension balance to investigate their CO2 adsorption behavior and performance.