Effect of thermal extraction on hydro-liquefaction property of residual coal. (1st September 2019)

• Record Type: Journal Article
• Authors: Wang, Zhicai; Wang, Qian; Hu, Runan; Pan, Chunxiu; Wang, Xiaoling; Ren, Shibiao; Lei, Zhiping; Kang, Shigang; Yan, Jingchong; Shui, Hengfu
• Is Part Of: Fuel. Volume 251(2019)
• Page Start: 474
• Page End: 481
• Publication Date: 2019-09-01
• Subjects: Low rank coal -- Thermal extraction -- Thermal extraction residue -- Hydro-liquefaction; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2019.04.063
• Languages: English
• ISSNs: 0016-2361

Abstract

Abstract: Thermal extraction (TE) of low rank coal with low boiling point solvent is an important approach to obtain organic chemicals, but it remains a great deal of thermal extraction residue (TER) due to low extraction yield. In this paper, Xilinguole lignite (XL) and Shenfu sub-bituminous coal (SF) were extracted by toluene and toluene/methanol mixed solvents at 250–350 °C to obtain TERs. Then the obtained TERs were hydro-liquefied to investigate their hydro-liquefaction property under mild conditions. By combination with the structural characterizations of TER and its liquefied products, it was found that TE can separate small molecular compounds, and improve the hydro-liquefaction performance of TER. Rising TE temperature and adding appropriate methanol to toluene can increase the TE yield and the oil + gas (O + G) yield of TER hydro-liquefaction, especially for XL which containing abundant oxygen functional groups. The effects of heat-induced relaxation of non-covalent bonding associated structure and solvent-induced cleavage of covalent bonds on the TE and the hydro-liquefaction of TER were discussed.