Effect of H<sub>2</sub> and CO as pyrolysis atmosphere on chemical structure of char by XRD and Raman methods

ZHANG Xiao-rui; ZOU Chong; ZHAO Jun-xue; MA Cheng; HU Bing; LIU Shi-wei; HE Jiang-yong

Volume 47 Issue 11

Nov. 2019

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Article Navigation > Journal of Fuel Chemistry and Technology > 2019 > 47(11): 1288-1297

ZHANG Xiao-rui, ZOU Chong, ZHAO Jun-xue, MA Cheng, HU Bing, LIU Shi-wei, HE Jiang-yong. Effect of H2 and CO as pyrolysis atmosphere on chemical structure of char by XRD and Raman methods[J]. Journal of Fuel Chemistry and Technology, 2019, 47(11): 1288-1297.

Citation:

ZHANG Xiao-rui, ZOU Chong, ZHAO Jun-xue, MA Cheng, HU Bing, LIU Shi-wei, HE Jiang-yong. Effect of H₂ and CO as pyrolysis atmosphere on chemical structure of char by XRD and Raman methods[J]. Journal of Fuel Chemistry and Technology, 2019, 47(11): 1288-1297.

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Effect of H₂ and CO as pyrolysis atmosphere on chemical structure of char by XRD and Raman methods

School of Metallurgical Engineering, Xi'an University of Architecture and Technology, Xi'an 710055, China

Funds:

National Natural Science Foundation of China 51374166

National Natural Science Foundation of China 51704224

Shaanxi Provincial Key Research and Development Program Funding Project 2017TSCXL-GY-04-01

Shaanxi Provincial Key Research and Development Program Funding Project 2015Ktzdsf01-04

Shaanxi Provincial Association of Science and Technology Youth Talents Lifting Plan 20190603

Shaanxi Provincial Department of Education Serves Local Special Projects 17JF012

More Information

Corresponding author: ZOU Chong, Tel:13572459737, E-mail:zouchong985@163.com; ZHAO Jun-xue, Tel: 15191573683, E-mail:Zhaojunxue1962@126.com
Received Date: 2019-07-08
Rev Recd Date: 2019-09-14

Available Online: 2021-01-23

Publish Date: 2019-11-10

Abstract

Abstract

XRD and Raman spectroscopy were used to study chemical structure evolution of Shenmu coal in the main pyrolysis temperature range (450-750℃) and three pyrolysis atmospheres (N₂, H₂-containing and CO-containing). Correlation of structural parameters obtained by the two methods was compared. The results show that the char prepared by pyrolysis of raw coal in N₂ has a continuous increase in the size of carbon crystallites in the transverse direction, a gradual increase of spacing in the longitudinal direction, and a sharp change of stacking height around 650℃. Raman parameter A_D₁/A_G increases, while A_G/A_all decreases, indicating a decrease in proportion of the ordered char structure. The H₂-containing atmosphere promotes the longitudinal development of the carbon crystallite structure, increases the conversion of small molecule groups and the ordered degree of char. The influence of CO-containing atmosphere on the carbon crystallite structure parameters is less than that of the H₂ atmosphere. But below 700℃, the dense carbon particles produced by CO-containing atmosphere due to carbon deposition are entrapped on the char surface, resulting in an increase in the ordered degree of char carbon. There is a certain correlation between L_c and A_G/A_all, and d₀₀₂ and A_D₁/A_G of char; L_a has a good positive correlation with A_D₁/A_G.
- low rank coal,
- char,
- pyrolysis atmosphere,
- XRD,
- chemical structure,
- Raman spectroscopy

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References(23)

References

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