Chunxiu Pan

High temperature thermal extraction of xianfeng lignite and FT-IR characterization of its extracts and residues

Abstract High-temperature thermal extraction (TE) of Xianfeng lignite by different solvents was carried out, and FT-IR spectra of extracts and residues were determined. The results indicate that Xianfeng lignite shows the macro-molecular network structure by chemical bond cross-linking, in which some low molecular compounds are associated by non-covalent bond interaction. The TE can distinctly increase the extraction yields, which are up to 20.7% and 21.3% at 300°C in toluene and tetralin, respectively. The extracts result from the release of low molecular compounds by thermal rupture of non-covalent bonds at high temperature. Meanwhile, there is no obviously pyrolysis in the process of thermal extraction at 300°C. So the hydrogen donor solvent and hydrogen bond solvent can not increase the thermal extraction yield. The thermal extracts of Xianfeng lignite contain a great of aliphatic alkyl and carbonyl ester, a little of hydroxyl and aromatic structure. The solvent of thermal extraction shows distinctly influences on the constitution and structure of extracts.

Highly dispersed Ni/SBA-15 catalysts prepared with different nickel salts as nickel precursors: Effects of activation atmospheres

Abstract With nickel nitrate and nickel acetate as nickel precursors, a series of Ni/SBA-15 catalysts were prepared by using the impregnation method and activating in air or hydrogen atmosphere. The Ni/SBA-15 catalysts were characterized with XRD, H 2 -TPD, N 2 physisorption and online mass spectroscopy. Their catalytic properties were evaluated with hydrogenation of naphthalene as a model reaction. It was shown that activation in hydrogen greatly increased the Ni dispersion and catalytic activity of Ni/SBA-15 prepared with nickel nitrate, while activation in air significantly improved the sample prepared with nickel acetate. In terms of the thermal decomposition products of the catalyst precursors activated in different atmospheres, the affecting mechanism of the activation atmosphere on the Ni/SBA-15 catalysts prepared with different nickel precursors was proposed.

Promotion of Ni/clay catalytic activity for hydrogenation of naphthalene by organic modification of clay

Abstract A Ni/montmorillonite (MMT) catalyst was prepared by an impregnation method using cetyltrimethylammonium bromide (CTAB)-pillared MMT as the supporting matrix and was characterized using infrared spectroscopy, X-ray diffraction, H2 temperature-programmed desorption, N2 adsorption-desorption, and ultraviolet diffuse reflectance spectroscopy. The catalytic activity of the Ni/MMT for the hydrogenation of naphthalene was also evaluated. The results show that the organic modification of MMT greatly improved the Ni dispersion and textural properties of the Ni/MMT catalyst. The as-prepared Ni/MMT catalyst showed high naphthalene conversion (88.2%) in the hydrogenation reaction; this is much higher than those achieved using Ni supported on pristine MMT (13.1%), Al2O3-pillared MMT (24.2%), and SBA-15 (68.2%). As a result of thermal decomposition of CTAB pillars during reduction of the Ni/MMT catalyst, the CTAB pillars mainly play a role in the Ni/MMT catalyst during impregnation. A mechanism for the promotion of the Ni/MMT catalytic activity by organic modification during impregnation is proposed.

Co-thermal dissolution property of Shenfu coal and rice straw

Abstract The co-thermal dissolution (CTD) properties of Shenfu coal (SC) and rice straw (RS) in 1-methylnaphthalene (1-MN) at different temperatures were studied. It is found that RS gives much higher of thermal dissolution yield (TDY), suggesting its high thermal dissolution (TD) activity. But much amount of gas is produced in the TD process of RS, resulting in the low thermal soluble yield (TSY). For the TD of SC, although the TDYs of SC are much lower than those of RS, but the differences between TDY and TSY from the TD of SC are much smaller than those from the TD of RS. CTD of SC and RS shows that there exists synergistic effect which is the function of temperature. At 320 to 340°C the TSYs have positive synergistic effect. The experimental results are larger than corresponding calculated weighted mean values of the individual TD of SC and RS. While at all the TD temperatures studied, TDYs give negative synergistic effect. The largest enhancements in TSY of 7.9% comparing with corresponding calculated weighted mean values of the individual TD of SC and RS are obtained at 320°C. The mechanism of synergistic effect produced in CTD was discussed based on the characterization of TD soluble fractions.

Coliquefaction behaviours of Shenhua coal and sawdust catalysed by different catalysts

AbstractColiquefactions of a subbituminous coal and sawdust over four different coal liquefaction catalysts were studied, and the coliquefied products were characterised by elemental analysis, Fourier transform infrared spectroscopy and gel permeation chromatogram measurements. It is found that FeS+S and Co–Mo/Al2O3 catalysts have the highest catalytic activity for the liquefaction of Shenhua coal and sawdust respectively. There exists synergistic effect in the coliquefaction of Shenhua coal and sawdust, and the main synergistic interaction is reflected by the promotion of preasphaltene formation. The catalytic activities of the four catalysts in the coliquefaction are quite different from their catalytic activities in the individual liquefaction of coal and sawdust. FeS gives the lowest catalytic activity for the coal liquefaction among the four catalysts but has the highest promotion to the synergistic effect in conversion in the coliquefaction of Shenhua coal and sawdust. diminishes this synergistic ef...

Thermal Dissolution of Shenfu Sub-Bituminous Coal Promoted by Lignin

RESEARCH ARTICLE Thermal Dissolution of Shenfu Sub-Bituminous Coal Promoted by Lignin Huihui Wu, Hengfu Shui, Lei Yang, Xiaoling Wang, Chunxiu Pan, Zhicai Wang, Zhiping Lei, Shibiao Ren, Shigang Kang and Charles Chunbao Xu School of Chemistry & Chemical Engineering, Anhui Key Laboratory of Coal Clean Conversion & Utilization, Anhui University of Technology, Ma’anshan 243002, Anhui Province, P.R. China Department of Chemical and Biochemical Engineering, Western University London, Ontario, N6A 5B9, Canada

Study of Pyrolysis Behavior of Shenhua Coal Pretreated by Ionic Liquid 1-Ethyl-3-Methylimidazolium Acetate

Abstract The pyrolysis behaviors of Shenhu subbituminous coal (SSBC) after pretreated with 1-ethyl-3-methylimidazolium acetate (EMIA) were studied in this paper. It is found that the pretreatment of SSBC with ionic liquid EMIA has a significant effect on the pyrolysis behavior of SSBC. The pretreatment temperature significantly affects tar yield of SSBC pyrolysis. The pretreatment SSBC with EMIA at 100 °C, 150 °C, 200 °C results in the increase of pyrolysis tar yield by 26.8 %, 32.8 %, and 35.7 %, respectively, compared to that of SSBC coal pyrolysis. FTIR and TG analysis show that EMIA pretreatment changed oxygen-containing functional groups in SSBC, in particular, increased the content of a carboxyl group and ether bond in SSBC. Also, it is found that pretreatment of coal with ionic liquid EMIA has a significant desulfurization effect.