IDEAS home Printed from https://ideas.repec.org/a/eee/appene/v225y2018icp559-569.html
   My bibliography  Save this article

Fractal characteristics and reactivity evolution of lignite during the upgrading process by supercritical CO2 extraction

Author

Listed:
  • Li, Hongjun
  • Chang, Qinghua
  • Gao, Rui
  • Dai, Zhenghua
  • Chen, Xueli
  • Yu, Guangsuo
  • Wang, Fuchen

Abstract

In this study, an upgrading process of lignite with supercritical CO2 extraction under rather mild temperatures was studied as a possible method for producing clean solid fuel with less moisture and enhanced combustion reactivity. The fractal characteristics and reactivity evolution of two typical lignites during the upgrading process by supercritical CO2 extraction have been studied in present work. Two typical lignites and one subbituminous coal were extracted in different conditions by a semi-continuous supercritical CO2 extraction device and the evolution of coal pore structure was investigated by N2 and CO2 adsorption/desorption isotherms. Two fractal dimensions D1 and D2, at relative pressures 0–0.45 and 0.45–1, respectively, were calculated by the Frenkel-Halsey-Hill model. The combustion reactivity of raw and upgraded coals was studied by a thermogravimetric analyzer. The results indicate that the N2 quantity adsorbed in pores of upgraded lignite increases with the increase of extraction time and temperature which is consistent with the variation of specific surface area and total pore volume of upgraded lignite. The mesopores and micropores of upgraded HB lignite are developed whereas macropores and mesopores of upgraded ZT lignite are enlarged after supercritical CO2 extraction. It was found, D1 values of upgraded HB lignite decrease whereas D2 values increase slightly. Meanwhile, the D1 and D2 values of upgraded ZT lignite are all decreased. The D1 values are mainly affected by the influence of mesopores and macropores on specific surface area and D2 values are mainly affected by the effects of fine mesopores and micropores on total pore volume. We found that D1 values have a positive relationship with the average pore diameter whereas have a negative relationship with specific surface area and total pore volume. D2 values have a negative relationship with average pore diameter whereas have a positive relationship with specific surface area and total pore volume for the raw and upgraded lignite. The combustion reactivity of upgraded lignite is enhanced after supercritical CO2 extraction due to the improvement of specific surface area and total pore volume.

Suggested Citation

  • Li, Hongjun & Chang, Qinghua & Gao, Rui & Dai, Zhenghua & Chen, Xueli & Yu, Guangsuo & Wang, Fuchen, 2018. "Fractal characteristics and reactivity evolution of lignite during the upgrading process by supercritical CO2 extraction," Applied Energy, Elsevier, vol. 225(C), pages 559-569.
  • Handle: RePEc:eee:appene:v:225:y:2018:i:c:p:559-569
    DOI: 10.1016/j.apenergy.2018.03.174
    as

    Download full text from publisher

    File URL: http://www.sciencedirect.com/science/article/pii/S0306261918305245
    Download Restriction: Full text for ScienceDirect subscribers only

    File URL: https://libkey.io/10.1016/j.apenergy.2018.03.174?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    References listed on IDEAS

    as
    1. Chen, Zhan-Ming & Liu, Yu & Qin, Ping & Zhang, Bo & Lester, Leo & Chen, Guanghua & Guo, Yumei & Zheng, Xinye, 2015. "Environmental externality of coal use in China: Welfare effect and tax regulation," Applied Energy, Elsevier, vol. 156(C), pages 16-31.
    2. Wang, Chang'an & Wu, Song & Lv, Qiang & Liu, Xuan & Chen, Wufeng & Che, Defu, 2017. "Study on correlations of coal chemical properties based on database of real-time data," Applied Energy, Elsevier, vol. 204(C), pages 1115-1123.
    3. Zhang, Jie & Zheng, Nan & Wang, Jie, 2016. "Two-stage hydrogasification of different rank coals with a focus on relationships between yields of products and coal properties or structures," Applied Energy, Elsevier, vol. 173(C), pages 438-447.
    4. Ding, Lu & Gong, Yan & Wang, Yifei & Wang, Fuchen & Yu, Guangsuo, 2017. "Characterisation of the morphological changes and interactions in char, slag and ash during CO2 gasification of rice straw and lignite," Applied Energy, Elsevier, vol. 195(C), pages 713-724.
    5. Liu, Peng & Zhang, Dexiang & Wang, Lanlan & Zhou, Yang & Pan, Tieying & Lu, Xilan, 2016. "The structure and pyrolysis product distribution of lignite from different sedimentary environment," Applied Energy, Elsevier, vol. 163(C), pages 254-262.
    6. Chen, Guifang & Yang, Xinfei & Chen, Shouyan & Dong, Yong & Cui, Lin & Zhang, Yong & Wang, Peng & Zhao, Xiqiang & Ma, Chunyuan, 2017. "Transformation of heavy metals in lignite during supercritical water gasification," Applied Energy, Elsevier, vol. 187(C), pages 272-280.
    7. Cui, Tongmin & Fan, Wenke & Dai, Zhenghua & Guo, Qinghua & Yu, Guangsuo & Wang, Fuchen, 2016. "Variation of the coal chemical structure and determination of the char molecular size at the early stage of rapid pyrolysis," Applied Energy, Elsevier, vol. 179(C), pages 650-659.
    8. Rizkiana, Jenny & Guan, Guoqing & Widayatno, Wahyu Bambang & Hao, Xiaogang & Li, Xiumin & Huang, Wei & Abudula, Abuliti, 2014. "Promoting effect of various biomass ashes on the steam gasification of low-rank coal," Applied Energy, Elsevier, vol. 133(C), pages 282-288.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Feng, Gan & Kang, Yong & Sun, Ze-dong & Wang, Xiao-chuan & Hu, Yao-qing, 2019. "Effects of supercritical CO2 adsorption on the mechanical characteristics and failure mechanisms of shale," Energy, Elsevier, vol. 173(C), pages 870-882.
    2. Lu, Yanjun & Han, Jinxuan & Yang, Manping & Chen, Xingyu & Zhu, Hongjian & Yang, Zhaozhong, 2023. "Molecular simulation of supercritical CO2 extracting organic matter from coal based on the technology of CO2-ECBM," Energy, Elsevier, vol. 266(C).
    3. Zhao, Weizhong & Su, Xianbo & Xia, Daping & Hou, Shihui & Wang, Qian & Zhou, Yixuan, 2022. "Enhanced coalbed methane recovery by the modification of coal reservoir under the supercritical CO2 extraction and anaerobic digestion," Energy, Elsevier, vol. 259(C).
    4. Zhang, Xiaogang & Jin, Chao & Zhang, Decheng & Zhang, Chengpeng & Ranjith, P.G. & Yuan, Yong, 2023. "Carbon dioxide flow behaviour in macro-scale bituminous coal: An experimental determination of the influence of effective stress," Energy, Elsevier, vol. 268(C).
    5. Liu, Fang-Jing & Gasem, Khaled A.M. & Tang, Mingchen & Xu, Bang & Huang, Zaixing & Zhang, Riguang & Fan, Maohong, 2020. "Enhanced liquid tar production as fuels/chemicals from Powder River Basin coal through CaO catalyzed stepwise degradation in eco-friendly supercritical CO2/ethanol," Energy, Elsevier, vol. 191(C).
    6. Guo, Hongguang & Zhang, Yujie & Zhang, Yiwen & Li, Xingfeng & Li, Zhigang & Liang, Weiguo & Huang, Zaixing & Urynowicz, Michael & Ali, Muhammad Ishtiaq, 2021. "Feasibility study of enhanced biogenic coalbed methane production by super-critical CO2 extraction," Energy, Elsevier, vol. 214(C).

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Wang, Chang'an & Wu, Song & Lv, Qiang & Liu, Xuan & Chen, Wufeng & Che, Defu, 2017. "Study on correlations of coal chemical properties based on database of real-time data," Applied Energy, Elsevier, vol. 204(C), pages 1115-1123.
    2. Xu, Jun & Tang, Hao & Su, Sheng & Liu, Jiawei & Xu, Kai & Qian, Kun & Wang, Yi & Zhou, Yingbiao & Hu, Song & Zhang, Anchao & Xiang, Jun, 2018. "A study of the relationships between coal structures and combustion characteristics: The insights from micro-Raman spectroscopy based on 32 kinds of Chinese coals," Applied Energy, Elsevier, vol. 212(C), pages 46-56.
    3. Wei, Juntao & Gong, Yan & Guo, Qinghua & Chen, Xueli & Ding, Lu & Yu, Guangsuo, 2019. "A mechanism investigation of synergy behaviour variations during blended char co-gasification of biomass and different rank coals," Renewable Energy, Elsevier, vol. 131(C), pages 597-605.
    4. Lin, Xiongchao & Luo, Meng & Li, Shouyi & Yang, Yuanping & Chen, Xujun & Tian, Bin & Wang, Yonggang, 2017. "The evolutionary route of coal matrix during integrated cascade pyrolysis of a typical low-rank coal," Applied Energy, Elsevier, vol. 199(C), pages 335-346.
    5. Zhao, Jingyu & Deng, Jun & Chen, Long & Wang, Tao & Song, Jiajia & Zhang, Yanni & Shu, Chi-Min & Zeng, Qiang, 2019. "Correlation analysis of the functional groups and exothermic characteristics of bituminous coal molecules during high-temperature oxidation," Energy, Elsevier, vol. 181(C), pages 136-147.
    6. Wei, Juntao & Guo, Qinghua & Ding, Lu & Yoshikawa, Kunio & Yu, Guangsuo, 2017. "Synergy mechanism analysis of petroleum coke and municipal solid waste (MSW)-derived hydrochar co-gasification," Applied Energy, Elsevier, vol. 206(C), pages 1354-1363.
    7. He, Qing & Yu, Junqin & Song, Xudong & Ding, Lu & Wei, Juntao & Yu, Guangsuo, 2020. "Utilization of biomass ash for upgrading petroleum coke gasification: Effect of soluble and insoluble components," Energy, Elsevier, vol. 192(C).
    8. Xu, Jun & Su, Sheng & Sun, Zhijun & Qing, Mengxia & Xiong, Zhe & Wang, Yi & Jiang, Long & Hu, Song & Xiang, Jun, 2016. "Effects of steam and CO2 on the characteristics of chars during devolatilization in oxy-steam combustion process," Applied Energy, Elsevier, vol. 182(C), pages 20-28.
    9. Li, Yilin & Chen, Bin & Li, Chaohui & Li, Zhi & Chen, Guoqian, 2020. "Energy perspective of Sino-US trade imbalance in global supply chains," Energy Economics, Elsevier, vol. 92(C).
    10. Wesseh, Presley K. & Lin, Boqiang, 2018. "Optimal carbon taxes for China and implications for power generation, welfare, and the environment," Energy Policy, Elsevier, vol. 118(C), pages 1-8.
    11. Duan, Wenjun & Yu, Qingbo & Liu, Junxiang & Wu, Tianwei & Yang, Fan & Qin, Qin, 2016. "Experimental and kinetic study of steam gasification of low-rank coal in molten blast furnace slag," Energy, Elsevier, vol. 111(C), pages 859-868.
    12. Mardones, Cristian & Baeza, Nicolas, 2018. "Economic and environmental effects of a CO2 tax in Latin American countries," Energy Policy, Elsevier, vol. 114(C), pages 262-273.
    13. Zaini, Ilman Nuran & Gomez-Rueda, Yamid & García López, Cristina & Ratnasari, Devy Kartika & Helsen, Lieve & Pretz, Thomas & Jönsson, Pär Göran & Yang, Weihong, 2020. "Production of H2-rich syngas from excavated landfill waste through steam co-gasification with biochar," Energy, Elsevier, vol. 207(C).
    14. Ding, Lu & Dai, Zhenghua & Guo, Qinghua & Yu, Guangsuo, 2017. "Effects of in-situ interactions between steam and coal on pyrolysis and gasification characteristics of pulverized coals and coal water slurry," Applied Energy, Elsevier, vol. 187(C), pages 627-639.
    15. Wang, Qian & Han, Kuihua & Wang, Peifu & Li, Shijie & Zhang, Mingyang, 2020. "Influence of additive on ash and combustion characteristics during biomass combustion under O2/CO2 atmosphere," Energy, Elsevier, vol. 195(C).
    16. Li, Nan & Ma, Ding & Chen, Wenying, 2017. "Quantifying the impacts of decarbonisation in China’s cement sector: A perspective from an integrated assessment approach," Applied Energy, Elsevier, vol. 185(P2), pages 1840-1848.
    17. Gupta, Saurabh & De, Santanu, 2022. "An experimental investigation of high-ash coal gasification in a pilot-scale bubbling fluidized bed reactor," Energy, Elsevier, vol. 244(PB).
    18. Lin, Junhao & Sun, Shichang & Cui, Chongwei & Ma, Rui & Fang, Lin & Zhang, Peixin & Quan, Zonggang & Song, Xin & Yan, Jianglong & Luo, Juan, 2019. "Hydrogen-rich bio-gas generation and optimization in relation to heavy metals immobilization during Pd-catalyzed supercritical water gasification of sludge," Energy, Elsevier, vol. 189(C).
    19. Tao, Meng & Jl, Xie & Xm, Li & Jw, Ma & Yang, Yue, 2020. "Experimental study on the evolutional trend of pore structures and fractal dimension of low-rank coal rich clay subjected to a coupled thermo-hydro-mechanical-chemical environment," Energy, Elsevier, vol. 203(C).
    20. Li, Dedi & Liu, Jianzhong & Wang, Shuangni & Cheng, Jun, 2020. "Study on coal water slurries prepared from coal chemical wastewater and their industrial application," Applied Energy, Elsevier, vol. 268(C).

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:eee:appene:v:225:y:2018:i:c:p:559-569. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Catherine Liu (email available below). General contact details of provider: http://www.elsevier.com/wps/find/journaldescription.cws_home/405891/description#description .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.