JOURNAL OF SEPARATION SCIENCE
·
2019
·Vol. 43
·期 4
·839-846
·
IF 2.516
Guo Yu,Xing Fan,Xue-Ming Dong,Rui-Yu Wang,Yun-Peng Zhao,Hong-Cun Bai,Tian-Sheng Zhao,Qing-Jie Guo,Xian-Yong Wei
Dayan lignite was subjected to thermal dissolution sequentially with cyclohexane, acetone, and methanol. Each thermal dissolution extract was subjected to further separation/enrichment using column chromatography, which was sequentially eluted with petroleum ether, a mixture of ethyl acetate and petroleum ether (vol:vol = 1:1), and ethyl acetate. The three thermal dissolution extracts and nine enrichment subfractions were characterized by an Orbitrap mass spectrometry equipped with an atmospheric pressure chemical ionization ion source. The mass spectrometry data were also statistically analyzed by principal component analysis, which can reduce the dimensionality of data and classify multiple samples according to principal components. Identified compounds in the extracts and subfractions are classified into eight classes according to the heteroatom distribution. Hydrocarbon class is mainly presented in the petroleum ether fraction, and oxygen class, nitrogen class, and oxygen-nitrogen class are distributed in both petroleum ether/ethyl acetate and ethyl acetate subfractions. The combination of different analytical methods enhances the understanding of coal at the molecular level and provides important data for downstream refining processes.
研究领域:
化学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
·
2024
·
IF 5.6
Meilu Hao,Peng Liang,Miaomiao Tian,Songze Li,Yue Gao,Yaqing Zhang,Xizhuang Qin,Wenrui Zhang,Tiantian Jiao
To efficiently utilize the oxygenated structures in lignite and obtain value-added oxygenated compounds, this study proposes a low carbon cascading utilization of Zhaotong lignite (ZT) through thermal dissolution and pyrolysis. The selectivity of ethanol (ET), tetrahydrofuran (THF) and ethyl acetate (EA) for oxygenated compounds in thermal dissolution, and the enrichment of thermal dissolution-pyrolysis on oil phases were investigated. The results show that sequential thermal dissolution is selective for different oxygenated compounds in ZT. ET shows selectivity for esters at 350 °C-2 MPa and for phenols at 350 °C-6 MPa. THF and EA are selective for naphthols and esters at 350 °C-6 MPa, respectively. Compared with the single process of thermal dissolution or pyrolysis, thermal dissolution-pyrolysis can significantly increase the oil phases yield with high value-added, in which ET, THF and EA increase the oil phase yields by 24.81 wt%, 13.66 wt% and 7.90 wt%, respectively. In particular, 59.15 wt% of the oxygen is distributed in light oil, and 9.79 % phenols as well as 1.56 % esters are enriched into light oil during thermal dissolution-pyrolysis process of ET. High value-added oxygenated compounds can be selectively enriched by appropriate solvents, at the same time, the quality of pyrolysis tar can be improved and the carbon emissions could be reduced.
研究领域:
化学工程
·
能源科学
✓ 已验证
DOI
高影响因子
International Journal of Minerals Metallurgy and Materials
·
2019
·Vol. 26
·期 12
·1512-1522
·
IF 1.221
Zhao Jun,Zuo Hai-bin,Wang Jing-song,Xue Qing-guo
The high-value utilization of low-rank coal would allow for expanding energy sources, improving energy efficiencies, and alleviating environmental issues. In order to use low-rank coal effectively, the hypercoals (HPCs) were co-extracted from two types of low-rank coal and biomass via N-methyl-2-purrolidinone (NMP) under mild conditions. The structures of the HPCs and residues were characterized by proximate and ultimate analysis, Raman spectra, and Fourier transform infrared (FT-IR) spectra. The carbon structure changes within the raw coals and HPCs were discussed. The individual thermal dissolution of Xibu (XB) coal, Guandi (GD) coal, and the biomass demonstrated that the biomass provided the lowest thermal dissolution yield Y 1 and the highest thermal soluble yield Y 2 at 280°C, and the ash content of three HPCs decreased as the extraction temperature rose. Co-thermal extractions in NMP at various coal/biomass mass ratios were performed, demonstrating a positive synergic effect for Y 2 in the whole coal/biomass mass ratios. The maximum value of Y 2 was 52.25wt% for XB coal obtained with a XB coal/biomass of 50wt% biomass. The maximum value of Y 2 was 50.77wt% for GD coal obtained with a GD coal/biomass of 1:4. The difference for the optimal coal/biomass mass ratios between XB and GD coals could be attributed to the different co-extraction mechanisms for this two type coals.
研究领域:
能源化学
·
煤化工
·
生物质转化
·
热化学转化
·
资源综合利用
✓ 已验证
DOI
高影响因子
FUEL
·
2022
·
IF 8.035
Yang-Yang Xu,Xing Fan,Wen-Long Mo,Turghun Muhammad,Xiang Bai,Binoy K. Saikia,Xian-Yong Wei,Feng-Yun Ma
Three soluble fractions (SFs) of a low-rank coal were obtained by sequential thermal dissolution (TD) using cyclohexane, toluene and methanol as the solvent. SFs were further separated using preparative high-performance liquid chromatography (HPLC) to obtain subfractions. Both SFs and subfractions were characterized by gas chromatography/mass spectrometry (GC/MS). Low polar compounds such as alkanes and arenes were enriched by cyclohexane. A large number of arenes and esters were detected in toluene extracts. Strong polar compounds like phenols were concentrated by methanol. After the separation by using preparative HPLC, more phenols, alcohols, esters and ketones were identified in subfractions, and the number of compounds detected by GC/MS increased by around 3 times. In addition, two trace compounds, (2,6-dimethoxybenzoyl chloride and tetrachloro-o-benzoquinone), were identified and one compound, 1,4-benzene-dicarboxylic acid-bis(2-ethylhexyl) ester, was enriched to 89.9% after separation. Two unsupervised analysis methods, hierarchical cluster analysis and principal components analysis, revealed the differences in distributional and compositional features of SFs and subfractions.
研究领域:
煤炭化学
·
分析化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY CONVERSION AND MANAGEMENT
·
2021
·
IF 9.709
Zhenzhong Hu,Xian Li,Yiming Sun,Omar Donovan Dacres,Yuxian Wang,Hongyun Hu,Huan Liu,Guangqian Luo,Hong Yao
A novel treatment denoted as the “Thermal-dissolution based carbon enrichment (TDCE)” was proposed in our previous work to effectively deoxygenate and de-ash biomass under mild conditions. The main reactions during this process occurred in a highly-dispersed and inert medium, thus its mechanism was unclear. In this study, cellulose was chosen as the model compound to investigate the underlying reaction mechanisms of TDCE process. It was confirmed that three distinct stages were involved in this process, which were physical dissolution stage, intramolecular deoxygenation and rearrangement stage, and stabilization stage. The deoxygenation attributed to the intramolecular dehydration at around 300 °C and the formations of CO 2 and CO through subsequent aromatization in liquid phase at around 350 °C. Around 67% and 19% of oxygen were removed by these two pathways, respectively. About 80% of carbon remained in the solid products in all conditions. A two-step process was verified for the aromatic substance formation: furan structure formation at the beginning and the subsequent conversion to benzene ring. Especially, unlike large molecular bio-char formation in conventional pyrolysis, small molecular aromatics were formed in TDCE process. Undoubtedly, the highly-dispersed and inert medium contributed to these intramolecular reactions and suppressed the intermolecular reactions, although it wasn’t involved in the chemical reactions. Hence, the unique reaction mechanism of biomass in a highly-dispersed medium was specified, providing theoretical guidance to the practical application of TDCE method.
研究领域:
能源与燃料
·
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Zhengzhi Zhang,Honglei Yan,Zhanku Li,Muxin Liu,Jingchong Yan,Weidong Zhang,Zhicai Wang,Zhiping Lei,Shibiao Ren,Hengfu Shui
Understanding the structural characteristics of high-sulfur coking coals is essential for the effective use of high-sulfur coals. In this study, thermal dissolution was employed to separate the Duizhen high-sulfur coking coal (DZ) into an extract (DZE) and a residue (DZR). The influence of the structural differences between DZE and DZR on sulfur migration behavior was further investigated, and the quality of the cokes from co-pyrolysis of DZ with DZE and DZR was evaluated. The results indicate that DZE is rich in aliphatic chain structures and oxygen-containing functional groups, whereas DZR retains a higher content of aromatic matrix and ash. DZE promotes the migration and transformation of sulfoxides and thiophenes by releasing reactive H and enhancing mass transfer. In contrast, the highly aromatic structure of DZR tends to bind with reactive sulfur species, forming stable sulfur-containing compounds, which thereby inhibits the release of H 2 S. Functioning as both a hydrogen donor and a binder modifier, DZE not only enhances synergistic desulfurization during co-pyrolysis but also contributes to improved coke quality. Although DZF also supports desulfurization to some extent, its limited caking properties and elevated ash content adversely affect the structural integrity and overall quality of the resulting coke. This study further explored the synergistic effects occurring during the co-pyrolysis process, revealing how the distinct structural features of the separated fractions influence sulfur migration behavior. This study provides theoretical basis and technical pathways for the clean and efficient conversion and resource utilization of high-sulfur coal.
研究领域:
煤化学
·
能源化工
·
材料科学
·
洁净煤技术
·
热解化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2021
·
IF 6.609
Yang-Yang Yan,Chu-Fan Wang,Xing Fan,Zhen-Yu Gao,Wen-Han Wei,Guo-Ming Zhao,Peng Liang,Ran-Ran Hou,Xian-Yong Wei
Due to the low concentration of minor compounds and the detection limit of instruments, numerous compounds in the thermal dissolution (TD) extract of coals cannot be detected. Therefore, it is necessary to introduce solid phase microextraction (SPME) for sampling before analysis, which can enrich compounds in mixtures with similar molecular structures and exclude interferences from other components. In this work, partial species in the TD extract of Zhaotong lignite were enriched by SPME with a polydimethylsiloxane (PDMS) coating. The enrichment characteristics of the coating on TD extract were examined by gas chromatography-mass spectrometry (GC–MS). Nitrogen-containing compounds and sulfur-containing compounds were removed from the enriched species, and the content of aliphatic hydrocarbons increased from 30.0% to 93.2% after enrichment. Oxygenated aromatic compounds with structures similar to the long-chain siloxane bonds of PDMS were also enriched. This study establishes a SPME method and provides a basis for the analysis of lignite and its derivatives.
研究领域:
能源化学
·
分析化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）