AUTHOR=Lou Yi , Su Yuliang , Gao Wei , Wang Wendong , Xiong Wei , Chen Jie , Xia Peng TITLE=Pore characteristics and fractal characterization variability of typical middle- and high-rank coal reserves: A case study of middle- and high-rank coal samples in western Guizhou JOURNAL=Frontiers in Energy Research VOLUME=10 YEAR=2022 URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.981530 DOI=10.3389/fenrg.2022.981530 ISSN=2296-598X ABSTRACT=

This article focused on the study of pore structure characteristics of Songhe and Linhua coal samples based on mercury injection experiments and high-pressure isothermal adsorption experiments. The results show that the pore structure of coal samples in the two mining areas is obviously different under the influence of metamorphic degree. The pores of Songhe mine coal samples, which are characteristic of middle-rank coal reserves, are predominantly open cylindrical pores with good connectivity to medium-to-large pores but poor absorption capacity. The tiny and medium pores of Linhua coal samples, which are characteristic of high-level coal reserves, have poor connectivity, dominated by conical pores with mostly closed and semi-closed pores. The pore size distribution of the middle-rank coal sample is multi-peaked, with better developed pore sizes, while the pore size distribution of the Linhua coal sample is bi-peaked, with micro and small pores developed. The pore fractal shape of high-rank coal reserves is higher than that of middle-rank coal reserves, and the complexity of permeable pore space and diffusive pore space of high-order coal reservoirs is higher than that of middle-order coal reservoirs.