Effects of de-ashing on the micro-structural transformation and CO2 reactivity of two Chinese bituminous coal chars
Two Chinese bituminous coals were de-ashed by hydrochloric and hydrofluoric acids; and their gasification reactivity with CO 2 were investigated using isothermal thermo-gravimetric method at constant temperatures of 900-1200°C, respectively. The effects of micro-structural transformation of coal ch...
| Main Authors: | , , , , , |
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| Format: | Journal Article |
| Published: |
2013
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| Online Access: | http://hdl.handle.net/20.500.11937/55140 |
| _version_ | 1848759545000624128 |
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| author | Lin, X. Wang, C. Tian, B. Zhang, Shu Zhou, J. Wang, Y. |
| author_facet | Lin, X. Wang, C. Tian, B. Zhang, Shu Zhou, J. Wang, Y. |
| author_sort | Lin, X. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | Two Chinese bituminous coals were de-ashed by hydrochloric and hydrofluoric acids; and their gasification reactivity with CO 2 were investigated using isothermal thermo-gravimetric method at constant temperatures of 900-1200°C, respectively. The effects of micro-structural transformation of coal chars before and after de-ashing were analyzed using X-ray diffraction (XRD) and laser Raman. Results indicate that the de-ashing treatment gives rise to the partial damage of carbon structure, and then forming more amorphous carbon during pyrolysis. Such amorphous carbon with high D band fractions of Raman spectrum demonstrate relatively less regular structure. The disordered structure allows more gasification agent (i. e. CO 2 ) penetrate into the inner of char, which probably promotes the gasification reactivity of it. The nano-rod structure forms during the raw coal char CO 2 gasification by the strong polymerization of pyrolysis gas. The de-ashing process is considered to diminish the support point for secondary polymerization, which causes more decomposition. The conversion ratio and reaction rate are increased. As a result, the reactivity of Shenhua coal char exhibits less change after de-ashing due to the competitive effect between vanishing of catalysis of ash and micro-structural transformation of char; in contrast, the reactivity of Yanzhou coal char after de-ashing presents apparent improving because of the less catalysis of ash and more micro-structural damage. |
| first_indexed | 2025-11-14T10:01:35Z |
| format | Journal Article |
| id | curtin-20.500.11937-55140 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T10:01:35Z |
| publishDate | 2013 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-551402023-08-02T06:39:09Z Effects of de-ashing on the micro-structural transformation and CO2 reactivity of two Chinese bituminous coal chars Lin, X. Wang, C. Tian, B. Zhang, Shu Zhou, J. Wang, Y. Two Chinese bituminous coals were de-ashed by hydrochloric and hydrofluoric acids; and their gasification reactivity with CO 2 were investigated using isothermal thermo-gravimetric method at constant temperatures of 900-1200°C, respectively. The effects of micro-structural transformation of coal chars before and after de-ashing were analyzed using X-ray diffraction (XRD) and laser Raman. Results indicate that the de-ashing treatment gives rise to the partial damage of carbon structure, and then forming more amorphous carbon during pyrolysis. Such amorphous carbon with high D band fractions of Raman spectrum demonstrate relatively less regular structure. The disordered structure allows more gasification agent (i. e. CO 2 ) penetrate into the inner of char, which probably promotes the gasification reactivity of it. The nano-rod structure forms during the raw coal char CO 2 gasification by the strong polymerization of pyrolysis gas. The de-ashing process is considered to diminish the support point for secondary polymerization, which causes more decomposition. The conversion ratio and reaction rate are increased. As a result, the reactivity of Shenhua coal char exhibits less change after de-ashing due to the competitive effect between vanishing of catalysis of ash and micro-structural transformation of char; in contrast, the reactivity of Yanzhou coal char after de-ashing presents apparent improving because of the less catalysis of ash and more micro-structural damage. 2013 Journal Article http://hdl.handle.net/20.500.11937/55140 restricted |
| spellingShingle | Lin, X. Wang, C. Tian, B. Zhang, Shu Zhou, J. Wang, Y. Effects of de-ashing on the micro-structural transformation and CO2 reactivity of two Chinese bituminous coal chars |
| title | Effects of de-ashing on the micro-structural transformation and CO2 reactivity of two Chinese bituminous coal chars |
| title_full | Effects of de-ashing on the micro-structural transformation and CO2 reactivity of two Chinese bituminous coal chars |
| title_fullStr | Effects of de-ashing on the micro-structural transformation and CO2 reactivity of two Chinese bituminous coal chars |
| title_full_unstemmed | Effects of de-ashing on the micro-structural transformation and CO2 reactivity of two Chinese bituminous coal chars |
| title_short | Effects of de-ashing on the micro-structural transformation and CO2 reactivity of two Chinese bituminous coal chars |
| title_sort | effects of de-ashing on the micro-structural transformation and co2 reactivity of two chinese bituminous coal chars |
| url | http://hdl.handle.net/20.500.11937/55140 |