Shibiao Ren

The dissolution of lignite in ionic liquids

A Xianfeng lignite (XL) was dissolved in a series of ionic liquids (ILs) at 200 °C. It was found that the anions of the imidazolium-based ILs are one significant factor to affect the extraction yield of XL and the chemical characteristics of extracts obtained from ILs extraction. The dissolution of ILs to lignite is related to the destructive ability of ILs to hydrogen bonds widely existing in lignite. The analyses of residues by in situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFT) indicate that the nature of ILs has a significant effect on the disruption of hydrogen bonds existing in lignite. The effective extraction of lignite results from the fracture of the hydrogen bonding network in lignite during lignite dissolving in ILs. Ionic liquid 1-butyl-3-methyl-imidazolium chloride [Bmim]Cl can dissociate significantly almost all of hydrogen bonds existing in lignite.

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.

Study on the thermal extraction of Xianfeng lignite in ionic liquid 1-butyl-3-methyl-imidazolium trifluoromethanesulfonate

Abstract The depolymerization behaviors of Xianfeng lignite (XL) in ionic liquid 1-butyl-3-methyl-imidazolium trifluoromethanesulfonate ([Bmim]OTf) was studied in this paper. Also, the thermal extracts and residues obtained from thermal depolymerization of XL at different extraction conditions were analyzed. It was found that [Bmim]OTf had good performance in the depolymerization of XL when the extraction was carried out at 280°C for 4 h with [Bmim]OTf/XL at 3.5. The extraction yield of XL with [Bmim]OTf defined as tetrahydrofuran solubles (THFS) reached to 20.1%. The depolymerization of XL with [Bmim]OTf was promoted markedly with the addition of tetralin (THN), H 2 and ZnCl 2 catalyst, and the yield of THFS reached to 30.0%, 36.9% and 46.8%, respectively. The results showed that the amount of hydrogen bonds in thermal extracts increased significantly with the addition of THN. The contents of aromatics and aliphatic hydrocarbon were enhanced greatly under the existence of H 2 and ZnCl 2 .

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.

Study on mild hydrogenation of Xianfeng lignite in ionic liquid

Abstract The liquefaction behaviors of Xianfeng lignite (XL) in ionic liquid 1-butyl-3-methyl-imidazolium tetrafluoroborate ([Bmim]BF4) under mild condition −350°C were studied. The effect of catalysts (FeS, ZnCl2, AlCl3 and FeCl3) on the XL liquefaction in [Bmim]BF4 were investigated and the liquefaction products obtained were analyzed by FT-IR spectra. It is found that the XL has a good hyrogenation activity in the presence of [Bmim]BF4, catalysts and tetralin (THN). XL liquefied product yield reaches to about 66.2% and the main liquefaction product is heavy fraction-tetrahydrofuran soluble (THFS) and tetrahydrofuran insoluble/N-methyl-2-pyrrolididinone soluble fractions (NS). The analyses of liquefied product by FT-IR show that the type of catalyst significantly affects the distribution and structure of liquefied product.

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...

Hydrotreatment of Heavy Oil from Direct Coal Liquefaction on a Sulfided Ni-W/AC Catalyst

Abstract Ni-W catalysts supported on activated carbon and Al2O3 were prepared by an incipient wetness impregnation method and characterized by x-ray diffraction and temperature programmed reduction. Heavy oil (distillation temperature: 320–340°C) derived from the direct coal liquefaction process using Shengli coal were hydrotreated using sulfided Ni-W catalysts at 400°C and 5.0 MPa initial H2 pressure. The results showed that the support had a significant influence on the reducibility of metal oxides, hydrodenitrogenation, and hydrodearomatization activities of coal-derived heavy oil. Ni-W/activated carbon exhibited higher decolor performance and hydrodearomatization activities for upgrading the coal-derived heavy oil than the Ni-W/Al2O3 catalyst.

Hydrotreating Behavior of Ni-Mo/SiO2-Al2O3 for the Upgrading of Heavy Oil From Coal Liquefaction

Abstract Ni-Mo/SiO2-Al2O3 with different Si/Al molar ratios were synthesized, characterized, and evaluated for upgrading of heavy oil derived from the direct coal liquefaction process. The results indicated that the Si/Al ratio has a significant influence on the dispersion of MoS2 and the hydrodenitrogenation activity. The larger Si/Al ratio causes the Ni-Mo/SiO2-Al2O3 to form the larger MoS2 crystallite. In the upgrading of coal-derived heavy oil, the hydrodenitrogenation and hydrodearomatization activities of Ni-Mo/SiO2-Al2O3 (Si/Al: 5) reached 53 and 60%, respectively, which are significantly higher than that of Ni-Mo/Al2O3.

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