(366b) Molecular Modeling and Adsorption Characterization of Micro-Mesoporous Kerogen Nanostructures

The aim of this work is a better understanding of structure and adsorption properties of organic porosity in kerogen, as it is related to predicting storage capacities of oil and gas, and hydrocarbon recovery. We hypothesize that the pore structure of kerogen can be represented as a network of mesopores distributed in the microporous matrix composed of packed kerogen molecules of given density. We generate 3D molecular models of kerogen micro-mesoporous structure with mesopores of different size and shape, and use GCMC simulations to calculate adsorption isotherms of typical adsorbates used for pore structure characterization. The kerogen matrix is generated by equilibrating the packing of kerogen molecules of given density and microporosity around mesopores. The system energy is minimized followed by MD simulations in NPT ensemble while decreasing the temperature. Adsorption isotherms of Ar, N₂ and CO₂ are generated in the 3D kerogen models of different levels of maturity, pore sizes and pore geometries, and compared with typical experimental isotherms on reference carbonaceous materials of different degree of graphitization.