Investigation on the composition of soluble portions from the extraction residue of Hanglaiwan subbituminous coal by thermal dissolution and alkanolyses. (15th December 2021)

• Record Type: Journal Article
• Authors: Gao, Yong; Wei, Xian-Yong; Li, Yan-Jun; Bai, Jin-Jun; Kang, Yu-Hong; Liu, Guang-Hui; Ma, Xiang-Rong; Li, Xiao; Lu, Cui-Ying; Bai, Hong-Cun; Zong, Zhi-Min
• Is Part Of: Fuel. Volume 306(2021)
• Publication Date: 2021-12-15
• Subjects: Subbituminous coal -- Thermal dissolution -- Alkanolyses -- Oxygen-containing bridged bonds; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2021.121747
• Languages: English
• ISSNs: 0016-2361

Abstract

Highlights: Making the oxygen-containing FGs-containing species soluble facilitates obtaining value-added chemicals. Cleavage of weak and medium-strength covalent bonds should be the main reaction during TD and alkanolyses. More condensed aromatics are released as soluble species during the alkanolyses, and such aromatics are more value-added chemicals . TD and alkanolyses result in removing low DBE O 1 - O 2 class species. Abstract: Solvent extraction (SE) of Hanglaiwan subbituminous coal (HSBC) was conducted with isometric carbon disulfide/acetone mixed solvent to obtain an extract, i.e., soluble portion 1 (SP1 ) and extraction residue (ER). Thermal dissolution (TD) and alkanolyses of the ER were carried out at 300 °C in cyclohexane ( CH ), ethyl acetate (EA), methanol ( M ), and ethanol ( E ), respectively, to obtain soluble portions (SPs) 2–5 (SP2 -SP5 ), which were analyzed with a gas chromatograph/mass spectrometer (GC/MS), Fourier transform infrared spectrometer (FTIRS), and quadrupole exactive orbitrap mass spectrometer (QPEOTMS). According to the analysis with GC/MS, the yields of SP4 (25.2%) and SP5 (38.6%) are much higher than those of SP2 (2.6%) and SP3 (7.1%), and SP1 -SP5 are rich in alkylbenzenes (ABs), while the semiquantitative analysis with FTIRS suggests that the cleavage of weak and medium-strength covalent bonds, especially oxygen-containing bridged bonds, should be the main reaction during the TD and alkanolyses. For O 1 - O 6 class species detected with QPEOTMS, O 1 - O 2 class species dominated in SP1, SP2, SP4, and SP5, while O 2 class species are predominant in SP3 . The main O 1 class species are alkyl-substituted arenols (ASAs) and acetophenones (APs II ), while the O 2 class species mainly consist of fatty acids (FAs), alkyl-substituted hydroquinones (ASHQs), methyl alkyl-substituted benzoates (MASBs), and arenediols. This investigation provides an effective approach for understanding the composition of the macromolecular networks (MMNWs) in HSBC.