Article
Thermodynamics
Qing He, Chen Cheng, Xinsha Zhang, Qinghua Guo, Lu Ding, Abdul Raheem, Guangsuo Yu
Summary: In this study, the pyrolysis process of low-ash coal and high-ash coal was investigated, revealing the pyrolysis mechanism of coal, non-isothermal kinetics, and the interaction between minerals and organics. The findings showed that coal pyrolysis occurs in two steps, and high-temperature inner minerals can promote graphitization. After demineralization, the distribution of pyrolysis activation energy becomes more concentrated.
Article
Chemistry, Physical
Lin Qian, Chao Tao, Chao Ma, Jinkai Xue, Feiqiang Guo, Xiaopeng Jia, Weijie Yan
Summary: The molecular structure of Zhundong coal (ZD) was characterized by physical detection techniques, and the complex structure was confirmed through various analyses, providing a reference for understanding the structural characteristics of ZD coal and helping to understand its reactivity.
JOURNAL OF MOLECULAR STRUCTURE
(2022)
Article
Energy & Fuels
Qichen He, Jun Xu, Xu Jiang, Cong Wang, Ming Jiang, Yufan Wei, Long Jiang, Kai Xu, Yi Wang, Sheng Su, Song Hu, Jun Xiang
Summary: This study investigated the effects of alkali and alkaline earth metallic species (AAEMs) on the heterogeneous evolution of coal/char structure during pyrolysis. The results showed that water-soluble AAEMs inhibit the release of volatiles, while ion-exchangeable AAEMs promote the release of volatiles at the early stage of pyrolysis. Both types of AAEMs increase the relative amount of small aromatic rings. Water-soluble AAEMs promote the crack and transformation of active components, while ion-exchangeable AAEMs promote the breakdown of chemical bonds between aromatic rings.
Article
Thermodynamics
Yang Liu, Peifang Fu, Bo Yu, Weijie Yan, Yumin Chen, Huaichun Zhou
Summary: This study revealed the intrinsic kinetic parameters required for predicting the combustion rate of Zhundong coal through isothermal and nonisothermal thermogravimetric analysis methods. The results showed a relationship between the activation energy, reaction order, and surface activation function of the coal samples.
Article
Chemistry, Multidisciplinary
Zhi-Hui Feng, Lin Liu, Wen-Long Mo, Xian-Yong Wei, Jun-Rong Yuan, Xing Fan, Wen-Cang Guo, Jia Guo, Jun-Min Niu
Summary: This study investigated the composition characteristics and pyrolysis performance of Karamay oily sludge, Zhundong subbituminous coal, and their mixture. The results showed that the mixture could generate combustible gases with reduced CO2 emissions.
Article
Energy & Fuels
Hongwei Yan, Baisheng Nie, Chao Peng, Peijun Liu, Xiaotong Wang, Feifei Yin, Jie Gong, Yueying Wei, Shuangshuang Lin
Summary: This study focuses on the construction of molecular models of coal using C-13 NMR tests and molecular simulations. The results show a positive correlation between the degree of coal metamorphism and structural stability, with the optimized model exhibiting strong spatial three-dimensionality and lower total molecular energy. The more branched C-C bonds have longer bond lengths and lower bond energies, leading to the generation of different types of reactive radicals upon breakage of chemical bonds in coal molecules.
Article
Energy & Fuels
Haihui Xin, Banghao Zhou, Wenjiang Tian, Xu-yao Qi, Mo Zheng, Wei Lu, He Yang, Xiaoxing Zhong, Deming Wang
Summary: This study reveals the pyrolysis mechanism of LHG coal from Zhundong coalfield by constructing models and calculating the pyrolysis process. The research findings are of great significance for guiding the control and transformation of coal fire.
Article
Energy & Fuels
Xiaohe Xiong, Yang Miao, Xuchao Lu, Houzhang Tan, Zia Ur Rahman, Peng Li
Summary: Different hydrocarbon species in coal pyrolysis gases have the potential to reduce NOx emissions. Alkanes yield in the gases is positively related to coal volatiles. Under different heating conditions, the generation behavior of alkanes differs from that of olefins and alkynes, with the yield varying with pyrolysis temperature.
Article
Energy & Fuels
Shouxi Jiang, Laihong Shen, Jingchun Yan, Xin Niu, Bin Hu, Lingchang Wang
Summary: This study investigated the effects of sodium on coal combustion and NOx emissions in Zhundong coal. The results showed that water-soluble sodium had negative effects on coal conversion and NO generation during traditional combustion. However, when chemical looping was applied to Zhundong coal combustion, the NO emission was largely restrained and mainly came from pyrolysis. Additionally, the gasification agent facilitated NO generation and CO2 had a stronger effect on chemical looping.
Article
Green & Sustainable Science & Technology
Santosh Kumar Sriramoju, Pratik Swarup Dash, A. Suresh, Tathagata Ray
Summary: Indian coal washing plants are under tremendous pressure to maintain clean coal yield and handle rejects. Conventional coal washing plants typically produce clean coal with 15-18% ash content and 35-50% yield through physical beneficiation techniques. Alternative processes for utilizing high-ash washery rejects are considered important due to environmental concerns.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Chemistry, Applied
Yi Chen, Zhongyang Luo, Mengxiang Fang, Kejian Lv, Jiansheng Zhou
Summary: The study found that under high-temperature pyrolysis conditions, controlling the heating rate, volatile-char interaction, and CH4 atmosphere can effectively enhance alkali metal pretreatment and eliminate carbon engulfment issues.
FUEL PROCESSING TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Xiaoling Wang, Shaoqing Wang, Yungang Zhao, Yu Liu
Summary: It is essential to conduct molecular simulations based on constructing a realistic aggregate model of coal in order to explore the thermal behavior of Zhundong coal from the perspective of maceral. This study constructed coal models of two Zhundong coal samples using various analytical methods and verified the final aggregate models through experiments and simulations. The constructed models provide a foundation for further exploration of the thermal reactivity of coal from the maceral aspects.
Article
Chemistry, Multidisciplinary
Nan Xiao, Xiaobo Hu, Wenlong Mo, Guanjun Jing, Xing Fan, Xiaoqin Yang, Shupei Zhang, Xianyong Wei
Summary: This study investigated the impact of kaolin on the structure and thermal conversion performance of Zhundong sub-bituminous coal (ZSBC) through pyrolysis, combustion, and gasification analysis using the TG-DTG technique. The results showed that the addition of kaolin enhanced the pyrolysis and combustion performance of ZSBC-K. Characterization of the char from ZSBC and ZSBC-K revealed that the addition of kaolin decreased the degree of graphitization and increased the oxygen content on the surface of the char. Moreover, the addition of kaolin increased the degree of disorder and the formation of char pores, which improved the gasification activity.
Article
Chemistry, Multidisciplinary
Haihui Xin, Jianguo Sun, Leilei Zhang, Wenjiang Tian, Banghao Zhou, Zuo Tang, Xu-Yao Qi, Cuicui Di, Xiaoxing Zhong, De-Ming Wang
Summary: This study investigated the reaction characteristic and oxidation parameters of pyrolysis residues of jet coal at different temperatures. It was found that the residue structure changed significantly at 450 degrees Celsius, with variations in functional group contents of hydroxyl, aliphatic hydrocarbon, and aromatic hydrocarbon. The pyrolysis residue at 450 degrees Celsius was most likely to reburn, with a significant increase in maximum combustion intensity compared to raw coal.
Article
Thermodynamics
Xu Jiang, Jun Xu, Qichen He, Cong Wang, Long Jiang, Kai Xu, Yi Wang, Sheng Su, Song Hu, Zhenyi Du, Jun Xiang
Summary: A quantification method for chemical structural heterogeneity of coal using Raman mapping technique was proposed in this study, and the heterogeneous chemical structure of coal was investigated. The results showed that the distributions of the chemical structure were highly uneven. Furthermore, the effects of chemical structural heterogeneity on pyrolysis behaviors were studied, and it was found that the heterogeneity significantly influenced the pyrolysis mechanisms and reactivity.
