Applicability of Consistency Criteria To Calculate the Brunauer–Emmett–Teller Surface Area of Graphite and Kerogen Mesopores

The Brunauer–Emmett–Teller (BET) method has been widely used to characterize surface area of various porous materials. As a result of some oversimplified assumptions, the performance of BET method can be compromised in micro- and mesopores. Thus, the consistency criteria were introduced to improve its performance. However, the applicability of the consistency criteria for kerogen mesopores has not yet been assessed. In this work, N 2 adsorption in graphite and kerogen mesopores is conducted by grand canonical Monte Carlo (GCMC) simulations at 77 K, while the accuracy of the standard BET method (BET_STD) and the BET considering consistency criteria (BET_CC) for surface area estimation is assessed. For graphite slit mesopores, BET_CC can better describe N 2 adsorption behaviors in graphite mesopores than BET_STD. For kerogen mesopores, the surface area from BET_CC has a better linear correlation with CH 4 excess/total adsorption under in situ conditions than that from BET_STD. In other words, the surface area from BET_CC is a better indicator than that from BET_STD to predict CH 4 adsorption behaviors. Our work provides important insights into BET surface area characterization in kerogen mesopores and optimization of characterization processes to better assess gas-in-place estimation in shale media.