Open AccessTemperature induced development of porous structure of bituminous coal chars at high pressure
Author(s) -
Natalia Howaniec
Publication year - 2016
Publication title -
journal of sustainable mining
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.623
H-Index - 17
eISSN - 2543-4950
pISSN - 2300-3960
DOI - 10.1016/j.jsm.2016.12.002
Subject(s) - porosity , microporous material , volume (thermodynamics) , coal , bituminous coal , materials science , pyrolysis , swelling , vaporization , specific surface area , chemical engineering , atmospheric temperature range , composite material , mineralogy , chemistry , thermodynamics , organic chemistry , physics , engineering , catalysis
The porous structure of chars affects their reactivity in gasification, having an impact on the course and product distribution of the process. The shape, size and connections between pores determine the mechanical properties of chars, as well as heat and mass transport in thermochemical processing. In the study the combined effects of temperature in the range of 973–1273 °K and elevated pressure of 3 MPa on the development of porous structure of bituminous coal chars were investigated. Relatively low heating rate and long residence time characteristic for the in-situ coal conversion were applied. The increase in the temperature to 1173 °K under pressurized conditions resulted in the enhancement of porous structure development reflected in the values of the specific surface area, total pore volume, micropore area and volume, as well as ratio of the micropore volume to the total pore volume. These effects were attributed to the enhanced vaporization and devolatilization, as well as swelling behavior along the increase of temperature and under high pressure, followed by a collapse of pores over certain temperature value. This proves the strong dependence of the porous structure of chars not only on the pyrolysis process conditions but also on the physical and chemical properties of the parent fuel