X.-Y. Wei

Sequential Thermal Dissolution of Geting Bituminous Coal in Low-boiling Point Solvents

Sequential thermal dissolution (STD) of Geting bituminous coal (GBC) in benzene, methanol, ethanol, and isopropanol was conducted at 150 to 300°C for 2 h. Anthracene was added into the system as the hydrogen acceptor to trace hydrogen transfer (HT) behavior during the STD. All of the soluble portions (SPs) were analyzed with a gas chromatograph/mass spectrometer. The once-through yields of SPs did not fluctuate obviously with raising the thermal dissolution (TD) temperature from 150 to 250°C, but significantly increased over 250°C. HT from GBC to anthracene in benzene, methanol, and ethanol occurred at 300°C and in isopropanol at 250°C. Unlike TD in benzene, alkanolysis significantly proceeded during TD in alkanols at 300°C.

The Enrichment of Condensed Arenes in Geting Bituminous Coal

Geting bituminous coal was sequentially and exhaustively extracted with petroleum ester, carbon disulfide, methanol, acetone, and isometric carbon disulfide/acetone mixed solvent at room temperature to afford extracts 1–5 (E1-E5). All the extracts were analyzed with a gas chromatography/mass spectrometer. As main components, a series of condensed arenes with 4–6 rings were detected in E2, but only extremely small amounts of the condensed arenes were detected in other extracts. The authors experiment provides an effective approach for enriching condensed arenes from coals, especially from bituminous coals, such as GBC.

Influence of Compound Additive CeO2-MxOy on Catalytic Performace of Pd/γ-Al2O3 Catalyst for One-step Synthesis of Dimethylether

A series of Pd/γ-Al2O3 catalysts with different types of compound additives were prepared by impregnation under microwave calcination; the physicochemical properties and catalytic performance of catalysts for one-step synthesis of dimethylether from sulfur-containing syngas were investigated. The results show that the catalysts added CeO2-ZrO2 showed much better catalytic performance and sulfur tolerance than those added CeO2-ZnO or CeO2-CaO in terms of CO conversion, methanol, and dimethylether selectivities and time space yield of dimethylether, which are closely related to higher pore volume and Pd dispersity, moderate CO adsorption, and moderate surface acidity of the catalyst. The optimum compound additive content was determined to be 2%CeO2-1%ZrO2. Under such optimum conditions, CO conversion, dimethylether selectivity, and time space yield of dimethylether are 63.2%, 68.5%, and 30.92 mmol·(ml·h)−1, respectively.

The Isolation of Condensed Arenes from Shenmu-Fugu Coal Liquefaction Residue

Shenmu-Fugu subbituminous coal liquefaction residue was exhaustively extracted with petroleum ether (PE) to afford PE-extractable fraction (PEEF), which was then eluted with petroleum ether through a silica gel-filled column. The PEEF and eluates were analyzed with a gas chromatographer/mass spectrometer and a Fourier transform infrared spectrometer. As a result, a number of 4- to 7-ring condensed arenes (CAS) were detected in the PEEF series of 4- to 6-ring CAs along with long-chain alkanes were isolated from the PEEF by column chromatography.

The compositional features of thermally soluble fractions from two Chinese coals in cyclohexane

Shengli lignite (SL) and Shenmu-Fugu subbituminous coal (SFSBC) were subjected to thermal dissolution in cyclohexane at 300°C for 1 h under hydrogen. The reaction mixtures were extracted with petroleum ether (PE) and the PE-extractable fractions (PEEFs) were analyzed with a gas chromatography/mass spectrometer. The results show that the PEEFs from thermally dissolved SL (TDSL) and thermally dissolved SFSBC (TDSFSBC) mainly consist of alkanes, alkenes, arenes, and oxygen-containing organic compounds (OCOCs); the yields of alkanes and alkenes in the PEEF from TDSFSBC are appreciably higher than those from TDSL, while the yields of arenes and oxygen-containing organic compounds in the petroleum ether-extractable fraction from thermally dissolved Shenmu-Fugu subbituminous coal are significantly lower than those from thermally dissolved Shengli lignite; arenols are dominant OCOCs in the PEEF from TDSL, while main OCOCs in the PEEFs from TDSFSBC are arenols and esters.

The Identification of Soluble Nitrogen-containing Organic Species in Two Chinese Lignites

Shengli lignite (SL) and Xiaolongtan lignite (XL) were extracted with carbon disulfide, benzene, methanol, acetone, and tetrahydrofuran sequentially. The OFs of organinitrogen compounds in the lignites and their residues were characterized by X-ray photoelectron spectroscopic analysis, and the nitrogen-containing organic species in the extracts were identified with gas chromatography/mass spectrometer. The results show that pyridinic nitrogen Np, pyrrolic nitrogen Np′, quaternary nitrogen Nq, and oxidized nitrogen No are the four OFs of organic nitrogen in the two lignites, and the content of Np′ in XL is higher than that in SL. The relative contents (RCs) of pyridines and quinolines in the extracts from XL are higher than those from SL, while the RCs of amides and amines in the extracts from SL were higher than those from XL.

The Effect of Pretreatment with H2O2 on the Oxidation of Shenfu Subbituminous Coal with NaOCl

Shenfu subbituminous coal (SFSBC) and pretreated SFSBC with H2O2 were subjected to oxidation with NaOCl at 30°C for 5 h. The results show that the pretreatment with H2O2 significantly increased the yields of water-soluble species (WSS), especially benzene carboxylic acids (BCA) and long-chain alkanedioic acids (LCADA), but substantially inhibited the formation of chloro-substituted alkanoic acids. The introduction of oxygen functional groups to SFSBC by the pretreatment (LCADA) could be responsible for the increase in the yields of WSS, especially BCA and LCADA.

The Zeolite-catalyzed Hydroconversion of Demineralized Shengli Coal Liquefaction Residue Under Microwave Irradiation

Microwave-assisted hydroconversions of demineralized Shengli lignite liquefaction residue (DMSLLR) were investigated over different zeolites in methanol at 140°C. The catalytic effects of the zeolites on the yields and compositions of methanol-soluble portions (MSPs) as well as the structural features of the MSPs and methanol-insoluble portions (MISPs) were examined. The results show that the yields of the MSPs over different zeolites follow the order: HZSM-5 > Hβ > HY > HM; HZSM-5 and Hβ observably promoted DMSLLR hydroconversion to gas chromatography/mass spectrometry-detectable normal alkanes and oxygen-containing organic species, whereas much more arenes were detected in the MSPs from hydrotreated DMSLLR with HY and HM.

Effect of Pretreatment on PAH Contents in Extracts from Xinwen Coal

Xinwen coal was pretreated with different processes, namely, swelled by (a) alcohol/water or by (b) benzene/alcohol mixed solvent, (c) oxidized with 30% H2O2, and (d) reduced the oxidized sample with NH2OH·HCl. The raw and pretreated samples were extracted with petroleum ether as the first step and then extracted with benzene as the second step, respectively. The extracts were analyzed by gas chromatograph-mass spectrometer, and four polycyclic aromatic hydrocarbons in the extracts are quantified. The results showed that all of the extracts yields and the contents of these four polycyclic aromatic hydrocarbons in extracts were different according to the pretreatments and the extracting solvents.

Identification of Organonitrogen Compounds in Petroleum Ether-soluble Fraction from a High-temperature Coal Tar

A high-temperature coal tar collected from Xuzhou Coking Plant, Saint-Gobain Pipelines (Xuzhou) Co., Ltd. was extracted with petroleum ether (PE) under ultrasonic irradiation and in a Soxhlet extractor. The residue was then extracted with methanol in the Soxhlet extractor. All the extracts were analyzed with gas chromatography/mass spectrometry (GC/MS). More than 250 organic compounds were detected in the PE-soluble fraction, but no GC/MS-detectable species (GC/MS-DSs) in the methanol-soluble but PE-insoluble fraction, indicating that all the GC/MS-DSs were extracted as PE. The GC/MS-DSs include various nitrogen-containing ones, many of which were seldomly reported. Nitrogen-containing organic compounds (NCOCs) detected are aniline, indole, quinoline, isoquinoline, methylquinolines, naphthonitriles, 8-(dimethyl-amino)-1-naphthonitrile, 3-methylindazole, acridine, benzoquinoline, benzoacridine, benzoisoquinolines, carbazole, methylcarbazole, phenanthridine, (Z)-N-(1-phenylethylidene)methanamine, benzocarbazoles, acenaphthopyridine and 2-methylcarbazole. Understanding molecular composition of the NCOCs in coal tar is important for developing an effective coal tar separation process.