Improved analytic methods for coal surface area and pore size distribution determination using 77 K nitrogen adsorption experiment |
| |
| Affiliation: | 1. Faculty of Resource and Safety Engineering, China University of Mining and Technology, Beijing 100083, China;2. School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522, Australia;1. Department of Chemistry and Biochemistry, Brigham Young University, Provo, UT 84602, USA;2. Department of Chemical Engineering, Brigham Young University, Provo, UT 84602, USA;1. Faculty of Safety Engineering, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China;2. National Engineering Research Center of Coal Gas Control, China University of Mining & Technology, Xuzhou, Jiangsu 221116, China;3. State Key Laboratory of Coal Mine Disaster Dynamics and Control (Chongqing University), Chongqing 400044, China;1. Institute of Resources & Environment, Henan Polytechnic University, Jiaozuo, Henan 454000, China;2. Henan Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region, Jiaozuo, Henan 454000, China |
| |
| Abstract: | 77 K nitrogen adsorption was the most widely used technique for determining surface area and pore size distribution of coal. Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) model are commonly used analytic methods for adsorption/desorption isotherm. A Chinese anthracite coal is tested in this study using an improved experimental method and adsorption isotherm analyzed by three adsorption mechanisms at different relative pressure stages. The result shows that the micropore filling adsorption predominates at the relative pressure stage from 6.8E−7 to 9E−3. Theoretically, BET and BJH model are not appropriate for analyzing coal samples which contain micropores. Two new analytic procedures for coal surface area and pore size distribution calculation are developed in this work. The results show that BET model underestimates surface area, and micropores smaller than 1.751 nm account for 35.5% of the total pore volume and 74.2% of the total surface area. The investigation of surface area and pore size distribution by incorporating the influence of micropore is significant for understanding adsorption mechanism of methane and carbon dioxide in coal. |
| |
| Keywords: | BET model BJH model D-A model Langmuir model |
| 本文献已被 CNKI ScienceDirect 等数据库收录！ |
|
