Kerogen nanoscale structure and CO2 adsorption in shale micropores

Abstract Gas storage and recovery processes in shales critically depend on nano-scale porosity chemical composition, but information about the nanoscale pore geometry connectivity of kerogen, insoluble organic shale matter, is largely unavailable. Using adsorption microcalorimetry, we show that once strong sites within network are taken, gas even at very low pressure governed by width rather than composition. A combination focused ion beam with scanning electron microscopy transmission reveal structure kerogen includes not only ubiquitous amorphous phase also highly graphitized sheets, fiber- onion-like structures creating voids accessible for sorption. Nanoscale bridge current gap between molecular size macropore scale existing models thus allowing accurate prediction sorption, diffusion properties shales.