ABSTRACT
Sulfur migration and distribution during pyrolysis of coal is quite complicated with the effect from different intertwined influencing factors, which requires extensive investigation. In this research, a typical Chinese pyrite-enriched coal was selected and pretreated through acid leaching combined with CrCl2 reduction. Thereby, minerals such as silicates and sulfates in the raw coal were effectively separated with the ash contents decreased from 37.74% to 0.57% while the inorganic sulfur was completely removed. Furthermore, programmed combined with isothermal pyrolysis of the selected coal and its two pretreated counterparts were conducted on the home-designed horizontal reactor to systematically ascertain the gaseous sulfur evolution. Possible sulfur formation pathways were revealed to explain the effect from the intertwined factors between the reaction temperature and the intrinsic factors as minerals distribution, different sulfur occurrences and their association with the organic matrix of coal. Finally, quantitative evaluation of the temperature effect on the sulfuric gases distribution and their yields was conducted with the total fraction of all the gaseous sulfur much decreasing from 5.6% to below 2.0% for the deashed and depyrited coal. Overall, through such a systematic investigation on the sulfur evolution from a typical pyrite-rich coal, comprehensive insights were obtained for future efficient sulfur control.
Nomenclature
LZ | = | The coal collected from the Liuzhi coal field in Guizhou Province, China |
LZ-RAW | = | The dried, ground coal parties of LZ coal |
LZ-DA | = | The deashed LZ coal by acid leaching |
LZ-DA-DP | = | The deashed coupled with depyrited LZ coal |
XRF | = | X-ray fluorescence analysis |
XRD | = | X-ray diffractometer |
XPS | = | X-ray Photoelectron Spectroscopy |
BE | = | binding energy |
Research Highlights
Sequential acid leaching combined with CrCl2 reduction was designed for directional removal of different forms of sulfur present in coal.
Programmed combined with isothermal pyrolysis of a Chinese typical pyrite-enriched coal was investigated.
Sulfur evolution behavior at different reaction temperatures was focused.
Quantitative evaluation of the reaction temperature on the gaseous sulfur distribution was made.
Disclosure statement
No potential conflict of interest was reported by the authors.
Additional information
Funding
Notes on contributors
Baowen Wang
Baowen Wang is a professor at North China University of Water Resources and Electric Power, China. He has been concentrated on coal clean combustion and pollutions alleviation for more than fifteen years, especially on coal chemical looping combustion with synergistic control of multiple pollutants and the chemical utilization of CO2 sequestered from coal combustion.
Chaofan Guo
Chaofan Guo has graduated from North China University with her master degree in Energy and Power Engineering discipline in 2022 and now is studying at Xi'an Jiaotong University as a PhD candidate with her research focus on coal clean combustion.
Gang Zhang
Gang Zhang has just received his master degree in 2023 from North China University of Water Resources and Electric Power with his research focus on carbon capture from coal combustion and efficient chemical utilization.
Tongqing Liu
Tongqing Liu has just received his master degree in 2023 from North China University of Water Resources and Electric Power with his research on synergistic carbon capture and sulfur control during coal chemical looping combustion.
Weiguang Li
Weiguang Li is a master candidate at North China University of Water Resources and Electric Power with directional control of the organic sulfur species in coal during chemical looping combustion.
Jingjing Ma
Jingjing Ma is a Lecturer at Ningxia University and has been devoted her effort to coal clean combustion, especially on efficient control of trace elements.