Abstract: To investigate the distribution characteristic of melting temperature of ash deposits deposited on different locations of furnace wall, comparison test on two combustion work conditions was made in trial furnace of black liquor coal slurry. Analysis was made on melting temperature, chemical composition, and mineral phase of ash deposits on furnace wall along journey of fume. The result shows that melting temperature of ash deposits at 155mm from outlet of burner on furnace wall is the lowest, and that of the highest is in the regions of 1000mm~1150mm from outlet of burner. Melting temperature of ash deposits on furnace wall assumes the distribution characteristic of elevation at the start followed by degradation gradually. Such distribution characteristic is correlated directly with transportation and deposition of mineral elementals, and related with combustion heat load to a certain degree.
Abstract: X-ray diffraction (XRD) was performed to analyze the mineral matter in coal ash from 1100℃ to 1500℃, with an interval of 50℃. Relative Intensity Ratio (RIR) method was used to calculate the content of each crystalline in coal ash. The amount of mullite increases with elevated temperature but that of SiO2 decreases. The transformation of mullite and SiO2 accords well with the binary phase diagram of SiO2-Al2O3. At high temperature, the amorphous mineral matters, mainly, aluminosilicates melt above ash softening temperature. During CO2 gasification at high temperature, the carbon conversion is hindered by the aluminosilicates melts, which cover the surface and block the pores of coal particles. Because of the short and ordered sequence of melts, FT-IR analysis was taken for the melts in coal ash after gasification. The structure alteration of aluminosilicates influences the surface tension of melts, which determines the interaction between coal particles and aluminosilicates.
Abstract: The experiments to simulate the slagging processes in the power plant boilers were carried out in a drop tube furnace with Shenhua coal, Zhungar coal and the blends of these two coals which are of different ash fusion temperatures. SEM and XRD techniques were used to analyze the surface morphology as well as the crystalline compositions of the residue. The result shows that a great mass of kaolinite and boehmite in Zhungar coal are turned ioto mullite. There is no boehmite and less kaolinite found in Shenhua coal, so there won't be too much mullite formed. Because the newly formed mullite can react with CaO at high temperature, so the mullite is not detected in the residue. Mullite with higher fusion temperature (1850℃) can significantly improve the coal ash fusion temperature, and the residue of Shenhua coal combustion does not contain any mullite, so it lacks the minerals as a “skeleton”, which is an important reason for that Shenhua coal has a relatively low ash fusion temperature.
Abstract: The apparent viscosity of coal-oil slurry of Shengli was measured using a high-temperature viscometer. Some factors that affect apparent viscosity change of Shengli coal-oil slurry were studied, such as mass fraction, particle size distribution, solvent properties, temperatures, shearing time, shearing rate and solvent swelling. The apparent viscosity of coal-oil slurry was compared in STR and REC from room temperature to approximately 350℃. The results show that Shengli coal-oil slurry is nonNewtonian fluid. Its apparent viscosity decreases firstly, then keeps invariability, finally increases with temperature rising. The temperature range for constant apparent viscosity and temperature for the apparent viscosity beginning to increase depend on solid concentrations, particle size distribution and solvent properties.
Abstract: The effects of temperatures and atmospheres on the sulfur transformation during pyrolysis of Liuzhi (LZ) raw coal and the chars (prepared by pyrolysis in a fixed bed reactor) were investigated by AP-TPR-MS combined with chemical analysis. The results show that only a small part of unstable organic sulfur in LZ coal can be removed by pyrolysis in the fixed bed reactor at 500℃ under N2 atmosphere, but pyrite and unstable organic sulfur can be completely removed at 700℃ under N2 atmosphere, and those sulfurs can also be removed at 500℃ under syngas atmosphere. The higher the temperatures, the greater the reactivity of sulfurs with syngas atmosphere, which is very similar to that under H2 atmosphere. However, the sulfur removal is less under 1.0% O2-N2 atmosphere like that under N2 atmosphere.
The characteristics of gasification reaction with steam or H2O/H2 mixed gases for Shenfu coal char pyrolyzed at 1200℃ was studied at 875℃~950℃ and ambient pressure by TGA. The curves of gasification rate and carbon conversion of coal char gasification with steam and H2O/H2 mixed gases are quite different. The gasification rates with steam decrease steadily. However, the gasification rates with H2O/H2 mixed gases decreases rapidly at lower carbon conversion and then slowly at higher carbon conversion, which is fitted difficultly by the existed models. A new gasification kinetics model was proposed based on the random pore model. Comparing the experimental data and the curve fitted by the new models, it can be seen that the experimental data of coal char gasification with H2O/H2 mixed gases can be fitted perfectly and the correlation coefficients are all above 0.996. The kinetics parameters of coal char gasification with H2O/H2 mixed gases for the new model are: Ea(activity energy)=251.990kJ/mol，k0(pre-exponential factor)=5.97877×109min-1.
Abstract: The steam gasification reactivity of 3 chars from rapid pyrolysis, slow pyrolysis of raw coal and rapid pyrolysis of demineralized coal was studied at 900℃～1050℃ and atmospheric pressure in thermal balance. At the same time, the kinetic parameters of three chars were calculated and the specific surface area was determined with carbon dioxide absorption at 273K. The results show that gasification rate increases with increasing temperature which is an important factor influencing the gasification rate. The gasification rate doubles with an increasing temperature of 50℃. The reactivity of demineralized char increases at the beginning of gasification and subsequently decreases at higher temperature. The reactivity of two rapid pyrolysis chars is far higher than that of char prepared at low heating rate. Ash in the char can catalyze the gasification reaction at early stage and obstructs the reaction at higher carbon conversion. For the activation energy values, the slow pyrolysis char is the smallest and the rapid pyrolysis char is the biggest. The original gasification reactivity shows independence on the specific surface area.
Abstract: Needle coke was prepared through the co-carbonization of toluene soluble fraction (TS) of coal tar pitch and waste polystyrene (WPS) in a tube bomb. The effects of the content of alkyl groups in the mesophase pitches on the properties of needle coke were investigated. By adding WPS into TS, the alkyl content in the mesophase pitches is increased from 12.0% to 33.3%; the resultant needle coke exhibits lower coefficient of thermal expansion (CTE) and better anisotropic orientation. The anisotropic indices of average length of vectors parallel to the CTE axis and average length of anisotropic unit vectors increase from 20.8μm and 23.4μm to 28.4μm and 28.8μm, respectively, while the CTE value decreases from 0.8×10-6 /K to 0.1×10-6 /K. The increase of alkyl content can reduce the viscosity of the carbonization system, which is beneficial to the development of flow texture and uniaxial orientation. Moreover, the sufficient gas evolution during the carbonization may also force the uniaxial arrangement of bulk mesophase molecules at the solidification stage.
Abstract: The thermogravimetric behaviors of biomass' chemical components (cellulose, hemicellulose and lignin) were studied in a thermogravimetric analyzer (TGA92) under air or syngas. The decomposing temperatures of the three components were examined. In order to understand the interaction between the three components, the synthesized samples (a mixture of these components with different ratios) were tested. Meanwhile, the experimental and calculated TG and DTG profiles were compared. The results show that both under air and syngas, among the three components, hemicellulose is the easiest one to be decomposed, while lignin is the most difficult one. Under different atmospheres the thermogravimetric behavior of each component is different. Both lignin and hemicellulose will affect the pyrolysis characteristic of cellulose under syngas, while both cellulose and hemicellulose will affect the combustion characteristic of lignin under air, which are related to the range of decomposing temperatures.
Abstract: The experiment of hydrogen production from catalytic steam reforming of bio-oil aqueous fraction was carried out in a bench scale fixed-bed reactor. The effects of temperature and sorbents were investigated. The optimal reaction temperatures for catalytic steam reforming of bio-oil aqueous fraction with and without sorbents were determined. The results show that at the best reaction conditions for bio-oil aqueous fraction reforming is at 800℃ under atmosphere pressure, at which, up to 60% of H2 and 10% of carbon monoxide in the effluent gas were obtained. Absorption of carbon dioxide increased hydrogen content in the effluent gas as well as hydrogen yield. 85% of hydrogen content was reached using CaO as sorbent at optimized reaction temperature of 600℃.Due to the decrease of the capacity for carbon dioxide capture by CaO at 650℃ during the reaction, the enhancement to hydrogen yield dropped significantly.
Abstract: Capillary gas chromatography coupled with pulsed flame photometric detector (GC/PFPD) was used for the qualitative and quantitative analyses of sulfur compounds in five diesels. The result show that the sulfur compounds present in straight run diesel (156.5℃~272.5℃) are mainly alkyl-substituted benzothiophenes (BTs)，and the dominant sulfur compounds are C3~4BTs, alkyl-substituted dibenzothiophenes (DBTs) in straight run diesel (204.0℃~363.0℃). Alkyl-substituted BTs and DBT are abundance and no other sulfur compounds were identified in the FCC diesel and hydrofining diesel. Sulfurcontaining compounds in coking diesel including almost all types of sulfides in middle distillate fractions.
Abstract: The relation between the hydrophilic-lipophilic balance (HLB) parameters of surfactants and the dispersion and electrical properties of the residue emulsified system were investigated. Droplet size and droplet distribution analysis were used to evaluate dispersion properties of the emulsions prepared with emulsifier blends of different HLB values, while the conductivity was used to appraise the electrical properties. The residue was emulsified and dispersed by the mixed emulsifier. The effects of surfactant HLB parameters on the dispersion properties of brine in the residue and the electrical properties were examined. The results showed that the emulsions prepared with emulsifier of various HLB values are also different in the dispersion and electrical properties; there is a non-linear correlation between the dispersion and electrical properties and HLB value of the mixed emulsifier.
Abstract: The oxidative desulfurization of dibenzothiophene (DBT) in n-octane as model oil with Brnsted acidic ionic liquids (ILs) Nmethyl-pyrrolidonium phosphate (\[Hnmp\]H2PO4) as catalytic solvent and H2O2 as oxidant was optimized by orthogonal experiments. 99.8% of DBT in the model oil was removed under the optimal conditions of molar ratio of H2O2 to sulfur of 16∶1, reaction temperature of 60℃, reaction time of 5h, and volume ratio of model oil to ILs of 1∶1. The desulfurization efficiency of actual diesel was 64.3% under the optimized conditions. The influences of the desulfurization efficiency of DBT decreased in the following order: oxidation temperature > oxidation time> molar ratio of H2O2/sulfur (O/S) > volume ratio of \[Hnmp\]H2PO4 to model oil (VIL/Vmodel oil), according to extreme analysis of orthogonal test. The IL \[Hnmp\]H2PO4 can be recycled six times without a significant decrease in activity.
Abstract: Ammonium thiosulfate as a novel sulfiding agent was used for presulfidation of hydrodesulfurization (HDS) catalysts. The presulfided Mo/Al2O3 catalysts with different molar ratios of S/Mo were prepared by impregnating Mo/Al2O3 catalysts with an aqueous solution of ammonium thiosulfate, followed by drying. Their characteristics of crystal phases, activation, and surface compositions were examined by X-ray diffraction, thermogravimetric analysis, and X-ray photoelectron spectroscopy. The S2- and S6+ in ammonium thiosulfate play different roles during the activation of presulfided catalysts. The S2- sulfides Mo and S6+ reacts with Al2O3 support, decreasing the interaction of support with the active metal. The collaboration between S2- and S6+ ions improves the sulfidation of MoO3. The best HDS performance was observed for the presulfided catalyst with S/Mo = 3. Its thiophene HDS activity is 17% higher than that of Mo/Al2O3 catalyst sulfided with H2S.
Abstract: Pt/Al2O3 with Pt loading of 5% was prepared and characterized by infrared spectroscopy (IR) combined with CO chemisorption, energy dispersive spectrometry (EDS), and transmission electron microscopy (TEM). The effects of reduction methods including commonly used dry reduction by gaseous H2 and wet reduction by sodium formate (HCOONa) aqueous solution on the surface states of Pt/Al2O3 were investigated. The results show that both the calcination and reduction can affect the particle sizes and surface sites of Pt. For the catalyst Pt/Al2O3 reduced by HCOONa solution, the ratio of terrace to step sites on the surface of Pt increases along with the calcination temperature. Subsequent to the identical calcination procedures, the wet reduction by HCOONa solution results in less residual chlorine and lower Pt dispersion than the dry reduction by gaseous H2. The violent reduction condition of HCOONa solution and the presence of water are both responsible for the agglomeration of Pt particles. The presence of water can facilitate the dissolution and removal of chlorine from the catalysts when reduced in an aqueous solution.
Abstract: The catalyst CuCo/γ-Al2O3 was prepared by coimpregnation and modified by glow discharge plasma, and then characterized by XRD, HOT, CO-TPD, and TPR. The performance of the plasma modified catalyst for CO hydrogenation to higher alcohols was investigated. The results showed that the plasma modification obviously promoted the dispersion of active species and caused the enrichment of active components on the catalyst surface. Meanwhile, the plasma treatment modified the interaction between the active species; the amount of strongly adsorbed CO on the catalyst surface was then increased remarkably. The catalytic performance of CuCo/γ-Al2O3 for higher alcohols synthesis was also enhanced by the plasma modification; the conversion of CO and the space time yield of higher alcohols over the plasma modified catalyst were higher than those over the catalyst prepared by the conventional impregnation method.
Abstract: The surface properties of zirconia calcined at different temperatures were characterized by XRD, LRS, NH3-TPD, CO2-TPD and CO-FTIR. The effect of zirconia surface properties on the catalytic performance of Cu/ZrO2 in CO hydrogenation was investigated. The results indicated that the surface properties of zirconia support, especially the surface base-acid properties, are affected significantly by the calcination temperature; the zirconia calcined at 450℃ exhibits high basicity and low acidity. The support surface properties also exhibit a great influence on the performance of Cu/ZrO2 catalyst for CO adsorption and CO hydrogenation. An active Cu/ZrO2 catalyst for CO hydrogenation can be obtained with zirconia calcined at 450℃ as the support.
Abstract: A series of FeMn/MgO catalysts were prepared by wetness impregnation method and different MgO which came from commercial MgO, thermal decomposed MgO and that prepared by co-precipitation method were used as supports. The catalytic performances of these samples for light alkenes synthesis through CO hydrogenation were investigated, and their properties were characterized by XPS, BET, XRD and H2-TPR techniques. These results showed that the sample supported on the co-precipitated MgO had the highest surface area (203.5m2/g), and had the highest activity for light alkenes synthesis through CO hydrogenation. Under the conditions of 340℃, 2.0MPa and 1600h-1, the CO conversion and the selectivity of C2=～C4= reached 91.36% and 58.48%, respectively. High surface area, high content active components well dispersed on the catalyst surface and the enhanced reduction property were important reasons for the perfect catalytic activities of these catalysts.
Abstract: NiO/α-Al2O3, NiO-CuO/α-Al2O3 and NiO-La2O3/α-Al2O3 catalysts were prepared by multistep impregnation method. The effects of CuO and La2O3 promoters on the ignition process of NiO/α-Al2O3 catalyst for catalytic partial oxidation of methane (CPOM) to synthesis gas were studied by temperature-programmed surface reaction (TPSR) technique as well. The results indicated that the CPOM reaction could not be ignited over the NiO/α-Al2O3 catalyst with or without pre-reduction during the CH4/O2-TPSR process till 910℃. The CPOM reaction could be ignited on the NiO-CuO/α-Al2O3 catalysts, which ascribed to the addition of CuO was beneficial to reduction of NiO with CH4 and restraining the re-oxidation of Ni0 by O2. The CPOM reaction could be ignited on the NiO-La2O3/α-Al2O3 catalysts too, which should be due to fact that the addition of La2O3 was beneficial to decrease the diffused resistance during the reduction process for reducing the size of nickel crystal.
Abstract: Soybean oil polyols was synthesized from epoxidised soybean oil (ESBO) and methanol via a ring-opening addition process. The effect of various catalysts on ESBO conversion and polyols formation was investigated and the product structure was characterized by IR and 1HNMR. HZSM-5 exhibits excellent catalytic performance in the transformation of ESBO into polyols due to the presence of Bronsted acid sites. With HZSM-5 as catalyst, the conversion of ESBO and hydroxyl value of the product polyols reach 92.4% and 177.4mgKOH/g, respectively, at 140℃ and a reaction time of 16h.
Abstract: Pyrolysis behavior and pyrolysis products of the scrap printed circuit boards were investigated using a TG-FTIR analysis system. The fluidized bed reactor was used to pyrolyze the scrap printed circuit boards particles under inert gas conditions, and the liquid products with a high boiling point and the solid products were analyzed using elemental analyzer and FT-IR. It is found that the liquid yield increases with temperature or gas velocity. The main component of liquid products is aromatic compounds with substituted functional group. The solid products mainly consist of carbon and fiberglas.
Abstract: The hydrolysis of cellulose under microwave irradiation using various metal chlorides as Lewis-acid catalysts was investigated. It was found that the cellulose conversion and product selectivity is strongly dependent on the reaction parameters like reaction temperature, time, microwave power, chloride type and amount used. In comparison with the conventional heating method, the microwave irradiation can accelerate the cellulose hydrolysis and improve the selectivity to glucose with good conversion. Among the metal chlorides investigated, copper chloride is the best catalyst for the hydrolysis of cellulose. For 0.5g of cellulose in 15g of water, when quitting the reaction once the temperature reached 225℃ under a microwave power of 800W, the cellulose conversion reached 72.6% with a glucose selectivity of 62.3% by using 0.05mmol of copper chloride as catalyst; the increase of the copper chloride amount to 0.15mmol led to a selectivity of 13.2% to 5-hydroxymethyl-2-furaldehyde (5-HMF); the further increase of the copper chloride amount to 0.30mmol resulted in a cellulose conversion as high as 90.6% but a glucose selectivity of only 6.7%.
Abstract: Using benzene and toluene as model compounds of biomass tar, the effect of temperature, steam content and space velocity on catalytic conversion were investigated in a fixed bed reactor over dolomite and cordierite catalyst. The results indicate that the conversion rate is improved with increasing temperature and decreasing space velocity. At 900℃, the conversion of toluene over cordierite and dolomite catalyst could reach 95%, using a molar ratio of steam/carbon (S/C mol ratio) equal to 1.5. At the same reaction temperature, the conversion of benzene over cordierite and dolomite catalyst could reach 61% and 53% separately, using a molar ratio of S/C mol ratio equal to 1.0. High steam content is favorable to adjust gas component. Stability experiment indicates that coke deposition is the key reason for catalyst deactivation.
Abstract: Co3V2O8 catalyst was prepared by co-precipitation method and was characterized by XRD, BET, H2-TPR, XPS and TEM in this paper. The catalytic performance for the oxidative dehydrogenation of propane to propylene has also been investigated. The results of H2-TPR and XPS illustrated that the transformation of lattice oxygen to mobile oxygen species (non-complete reduction oxygen) might promote the oxidation-reduction reaction between different valence vanadium, which led to abundant non-complete reduction oxygen O- and V4+ species formation over the Co3V2O8 catalyst surface. The active results showed that 49.45% and 33.74% propylene selectivity could be obtained at the reaction temperature of 425℃ and 475℃ respectively.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
