Abstract: Conversion of Xiaolongtan lignite to hydrogenrich gas was performed in supercritical water under conditions of 450℃~680℃, 23MPa~38MPa, and 1min~30min in the presence of CaO. The effects of Ca/C mol ratio and reaction conditions on the product distribution and yields of gas products were investigated. The yield of CO2 in gas product decreased and that of hydrogen increased with the increase of Ca/C mol ratio. At a Ca/C mol ratio of 0.42, nearly all CO2 is fixed and the mol fraction of hydrogen in gas product is about 48 ％. The increase in temperature leads to an increase in the carbon conversion and the yield of hydrogen, and the performance of CaO is significant at higher temperatures. Higher reaction pressure favors the conversion of coal and the formation of H2 and CH4. The effect of residence time is less significant compared with Ca/C mol ratio and temperature. Experiments of char gasification in SCW were also conducted. It shows that the addition of CaO can promote carbon gasification reaction and increase the yields of H2 and CH4.
Abstract: Coal liquefaction residue (CLR), coming from a direct coal liquefaction pilot plant, was used to investigate its rheological characteristics and the effects of temperature and oil, asphaltene, as well as solid content on its rheological characteristics. CLR is a kind of nonNewtonian pseudoplastic fluid, whose viscosity index decreases with increasing temperature, and approaches Newtonian fluid behavior at high temperature. The apparent viscosity of CLR drops greatly without peak as it is sensitive to temperature. After adding a little recycled oil (REC) into CLR, its apparent viscosity decreases remarkably. However, after the addition of a little asphaltene into CLR, its apparent viscosity increases at a low temperature and decreases at a high temperature. In addition, solid content is the factor of making the apparent viscosity increase all the time. All the results indicate that the apparent viscosity of CLR has a close relation with oil, asphaltene, and solid contents. The relationship between the apparent viscosity and temperature can be expressed by Arrhenius Equation. But there is a flex point during heating, and the viscous flow activation energy at the low temperature is greater than that at the high temperature.
Abstract: The microcrystal structure of Peicheng natural coke (Peicheng mine,Xuzhou), Hanqiao bituminous coal (Hanqiao mine, Xuzhou) and graphite (reagent) was studied by use of X-ray diffraction technique. The gasification characteristic of natural coke with CO2 was studied by thermogravimetry, which is compared with that of bituminous coal. The results show that the microcrystal structure of natural coke and anthracite is similar and there are no 101 diffraction peaks which reflect the three-dimensional structure of crystal lattice and crystallite characteristic of graphitization degree. The gasification reactivity of natural coke is less than that of bituminous coal, but it can get improved by adding the catalyst or increasing the gasification temperature. The CO2 gasification behavior of natural coke with kaliumbased, calciumbased and ironbased catalysts was examined. It is found that the kaliumbased catalyst has the best catalytic performance, and the calciumbased and ironbased catalysts are next. The gasification process of natural coke and bituminous coal can be described by the unreacted coreshrinking model. The kinetic parameters of the gasification reaction were obtained.
Abstract: The pore size distribution at different temperatures and laterally spatial locations during pyrolysis was investigated by mercury intrusion method coupling with SEM analysis. A vertical furnace with the diameter of 150mm and the height of 300mm was used to simulate the coking process. The results show that there are a lot of macropore and mesopore existed in semicoke. A regular variation of porosity and specific surface area is observed with coking temperature and spatial location. At the same coking temperature, the porosity and specific surface area firstly decrease and then increase from the brim to the center of coke bed. The porosity decreases with the increase of the coking temperature, but increases after 900℃. The specific surface area reaches the minimum value at 900℃, and then rapidly increases with the increasing of temperature. The pores with the diameter of >5.0μm dominate all the pore structures. The cumulative pore volume with the pore diameter of <0.4μm、0.4μm~5.0μm and >5.0μm reaches 10 %、20 % and 70 %, respectively, and the distribution peak lies in the pore size between 60μm and 150μm. The SEM analysis results also show that the rich macropore is existed in the semicoke and the larger pore diameter is observed in the center and brim of the coke cake.
Abstract: Pyrolysis characteristics and kinetics of wheat straw were investigated using a thermogravimetric analyzer coupled with Fourier transform infrared analyzer (TG-FTIR) under catalytic and noncatalytic conditions. The effects of pyrolysis temperature and catalyst on composition of volatile products were discussed. The pyrolysis parameters were obtained based on TG and DTG curves. The composition of pyrolysis products was online analyzed by FT-IR. The results show that two thermogravimetric peaks appear on DTG curves using nickel oxide and calcium oxide as catalyst, but only one peak appears without the catalysts. Thus the biomass pyrolysis characteristics can be improved under catalytic condition. Nickel oxide has more remarkable effect on increasing biomass pyrolysis yields, picking up volatile releasing rate, and decreasing apparent activation energy. CO and CO2 release peak is consistent with the maximal weight loss rate in DTG. CH4 is formed later than CO and CO2. In addition, using nickel oxide and calcium oxide as catalyst CO and CH4 yields increase, whereas CO2 yield decreases. While temperature is below 800℃, calcium oxide is more helpful to improve fuel gas composition during pyrolysis. When the temperature is above 800℃, nickel oxide has better catalytic effect.
Abstract: The Nibased monolithic catalyst was prepared by impregnation. The performance of the monolithic catalyst for the reforming of biomass fuel gas was studied at 750℃ for 108h. The results show that over the monolithic catalyst , the average CH4 conversion reaches 92%. The maximum conversion of CH4 is 93.8% . The average H2/CO mol ratio is 0.95 and the maximum H2/CO mol ratio is 1.15 . The conversion of CO2 reaches up to 88%. Naphthalene was added as the tar model compound. It is found that the tar is completely converted to H2, CO and trace lighter hydrocarbon compounds. The catalyst kept its activity during the 108h reaction. No pressure drop was detected in the reactor, which shows that the catalyst has excellent reforming activity and anticoking performance.
Abstract: The mean dipole moments of Dagang atmosphere residue (DGAR) fractions were investigated. DGAR can be partitioned into six fractions: saturates and light aromatics, heavy aromatics, light resins, middle resins, heavy resins, and asphaltenes. The mean dipole moments of these fractions are 1.19, 2.88, 3.79, 4.92, 6.36, and 11.70 Debye, respectively, which increase from saturates and light aromatics to asphaltenes. This result is consistent with the differences in solubility of solvents used in liquid chromatography separation. The contents of hydrogen, carbon, nitrogen, and sulfur in each fraction were also measured. Opposite to the polarity, the H/C atomic ratio of the residue fractions decreases from saturates and light aromatics to asphaltene. The ratio of S/C and N/C atomic ratio of the residue fractions vary in the same sequence of the mean dipole moment, which indicates that the heteroatom content is a factor that influences residue polarity.
Abstract: Six N-alkylpyridiniumbased ionic liquids, N-butylpyridinium nitrate ([BPy]NO3), N-ethylpyridinium nitrate ([EPy]NO3), N-butylpyridinium tetrafluoroborate ([BPy]BF4), N-ethylpyridinium tetrafluoroborate ([EPy]BF4), N-ethylpyridinium acetate([EPy]Ac), N-butylpyridinium acetate([BPy]Ac) were prepared and tested in the extraction desulfurization of gasoline. It is found that [BPy]BF4 has the best effect on the selective removal of sulfurcontaining compounds from gasoline at room temperature among these ionic liquids. The extraction rate of [BPy]BF4 is 45.5%. The desulfurization effect of [EPy]BF is the lowest. The used ionic liquids can be regenerated by rotary evaporation or re-extraction using tetrachloromethane.
Abstract: A six-lump kinetic model was derived on the basis of FCC reaction mechanism to represent the FCC naphtha olefin reformulation. Lumps were defined not only by their boiling range but also by their chemical compositions. Rate constants, frequent factors and activation energies were estimated based on the experimental data. The proposed model could not only predict successfully the yields, but also provide more information of the chemical compositions of naphtha. The model is useful for the study of how to reduce the olefin content of FCC naphtha.
Abstract: Zeolite REUSL (ultra stable zeolite L modified by rare earth ions) with different contents of composite rare earth (La and Ce) was prepared by ionexchange, substituted for REUSY of 5% as an active additive component of catalytic cracking catalyst. The catalytic cracking performance of the catalysts with the REUSL zeolites was evaluated by microactivity testing (MAT) using diesel oil as a feedstock, and compared with the catalyst containing the zeolite USL modified by single rare earth element of La or Ce. The results show that the performance of the catalyst added zeolite USL modified by a proper amount of composite rare earth into the FCC catalyst is superior to zeolite USL modified by single rare earth element. The new catalyst can decrease the content of olefins in gasoline and increase octane number of gasoline. When composite rare earth content in zeolite REUSL is about 0.4%, compared with catalyst without zeolite REUSL, MAT index increases 3.6 units, the content of olefins decreases 1.57 units, research octane number(RON) increases 2.08 units, and catalytic product distributions are more excellent.
Abstract: Commercial activated carbon (AC) samples were employed as catalysts to produce CO-free hydrogen from decomposition of methane in a fluidizedbed reactor. The primary experimental results show that conversion of methane attains about 8% and 11% at 850℃ and 900℃, respectively. It reaches 12% and 16% at 850℃ and 900℃, respectively, after treating AC in concentrated HNO3 solution. The reason is attributed to formation of lots of highly active sites due to decomposition of oxygencontaining groups on the surface of AC produced during treatment process. The promoting effect of 0.16% Ni loaded on treated AC by ion-exchange process on the activity of AC was clearly better than that by dry impregnation.
Abstract: The natural gas adsorbents were prepared with highsulfur petroleum coke as feed, potassium hydroxide as activation agent and sodium dodecylbenzene sulfonate (SDBS) as surfactant. Their pore texture and pore size distribution were measured and the activation mechanism was suggested. The results showed that the surfactant SDBS during preactivation process can enhance the homogeneity of mixed material, which is then evidently favorable for the activation of highsulfur petroleum coke. The micropore volume of the adsorbents GSR3 and GSR4, prepared under the optimal condition, were 1.0985cm3·g－1and 1.3193cm3·g－1, respectively; and the main pore size distribution was between 0.9nm and 1.5nm. Under 25℃ and the CH4 charging/discharging pressure of 3.5MPa and 0.1MPa, the CH4 mass uptake and effective desorption volume of the adsorbents GSR3 and GSR4 can be up to 0.139 and 0.145, and 111, and 115, respectively. Therefore, the highsulfur petroleum coke based adsorbents are much close to lowsulfur petroleum coke based adsorbents in quality.
Abstract: Partial oxidation of methane to syngas over NiCu bimetallic catalysts supported on La2O3 was studied. The catalysts were prepared by wet impregnation with different metal impregnate order and with different contents of Cu while keep Ni 30% constant. The results of the catalytic evaluation in a fixedbed reactor showed that the Ni-Cu/La2O3 had higher activity, the Ni-Cu co-impregnate was superior, and the catalysts with 5%～7% Cu loading had the best catalytic performance. In order to understand the Cu effect, the catalysts were characterized by XRD,TPR and SEM. Through XRD Ni-Cu alloy was observed in the Ni-Cu/La2O3 catalysts, the TPR results suggested that the alloy can reduce NiO at a lower temperature and produce more Ni site.SEM showed that a low carbon deposition was formed on NiCu/La2O3 which exhibited a stable activity.
Abstract: Molybdenum carbide of both β-Mo2C and α-MoC1-x crystalline forms was prepared by temperature programmed reaction (TPRe) between MoO3 and CH4/4H2. The structure and morphology of molybdenum carbide were characterized by XRD, BET, TEM, SEM and XPS. Its catalytic activity in the hydrogenation of carbon monoxide were investigated under 573K, 8.0MPa, GHSV=2000h－1, n(H2)/n(CO)=1.0. The results indicated that light hydrocarbons of C1～4 are the main products in the hydrogenation of carbon monoxide over molybdenum carbides, with the formation small amounts of alcohols (< 4%). Molybdenum carbide could then be a potential catalyst for the F-T synthesis or the alcohol synthesis.
Abstract: A series of CuO/ZnO/γ-Al2O3 catalysts with different Al2O3 contents were prepared using parallelslurrymixing method, in which an aqueous solution of Cu2+and Zn2+mixed nitrates and an aqueous solution of Na2CO3 were poured into a precipitation vessel containing γ-Al2O3 slurry in a parallelflow manner. The catalyst structure and its performance for methanol synthesis were investigated. The results indicated that Al2O3 as a structural promoter can inhibit CuO and ZnO crystallites from enlarging during calcination. The catalyst with a Cu∶Zn∶Al ratio of 4∶5∶1 exhibits the highest catalytic activity. With an increase in Al content, the amounts of (Cu0.3Zn0.7)5(CO3)2(OH)6 phase in the catalyst precursor before calcination shows a decrease, whereas those of Cu2CO3(OH)2 phase shows an increase; (Cu0.3Zn0.7)5(CO3)2(OH)6 in the precursor is beneficial to the catalytic activity of the final Cu/ZnO/γ-Al2O3 catalyst.
Abstract: The synthesis of dimethoxymethane (DMM) by selective oxidization of methanol over the catalyst rhenium supported on ZrO2 in a fixedbed reactor was investigated. It was found that higher temperature may promote the conversion of methanol but reduce the selectivity of DMM. The loading of rhenium on the catalyst exhibits a significant influence on methanol conversion and a maximum methanol conversion is obtained at a rhenium loading of 1.64%. XPS, H2-TPR and NH3-TPD suggested that ReOx/ZrO2 acts as a bifunctional catalyst in the reaction: the ReOx supported on ZrO2 is able to oxidize methanol, and then the reduced active sites contribute to the condensation of HCHO and methanol to form DMM.
Abstract: The soluble characteristic of dieselethanol blended fuel using cosolvent was investigated and its performance and exhaust emission behaviours in a diesel engine were examined. Four ethanoldiesel fuels named as E0, E5, E10 and E15 were prepared with the content of cosolvent being 1.5% and the contents of ethanol being 0 (20# neat diesel), 5%, 10% and 15% by volume, respectively. It was found that the composition of various hydrocarbons in the diesel fuel exhibits significant influences on the soluble characteristic and the addition of 10% ethanol and 1.5% cosolvent in the diesel can prevent the blend fuel from phase separation perfectly. The engine tests indicated that the brake specific fuel consumption increases gradually while the rated power and the maximum torque decrease with a growth in the ethanol content of blend fuel. As to the regulated exhaust emissions, the brake specific emissions of HC, NOx and PM (BSHC, BSNOx and BSPM) increase with the ethanol content in the blend fuel, but the increments of the BSNOx and BSPM emissions are not so obvious as NOx emission. The BSCO emissions tend to reduce with an increase in the ethanol content. Overall, the ethanoldiesel blend fuel with an ethanol content of 10% exhibited the optimum performance on engine operation and exhaust emission controlling.
Abstract: Activated coke (AC) supported V2O5 (V2O5/AC) is an efficient catalystsorbent for simultaneous SO2 and NO removal from flue gas at 150℃～200℃. It was found that this type of catalystsorbent can be effectively regenerated in the presence of NH3 at temperatures much lower than that required by AC under an inert atmosphere. Systematic experiments were performed in this study to know the effect of regeneration conditions on SO2 and NO removal activities in the subsequent cycles, including regeneration temperature (200℃～380℃), NH3 concentration (0%～5%), and regeneration time (10min～80min). Results indicate that the optimal regeneration conditions of SO2captured V2O5/AC are: 300℃, 3%～5% NH3 in an inert atmosphere, 60min. With the aid of elemental analysis and FT-IR characterization, it was found that the regeneration serves three roles: desorption of the adsorbed sulfur species from the catalystsorbent, surface modification by NH3, and adsorption (storage) of NH3 on the surface. The roles of NH3 are mainly in surface modification (chemical effect) and storage of NH3 on the surface (physical effect). The former occurs at relatively higher temperatures and favors SO2 removal and the latter is more significant at lower temperatures and favors NO removal.
Abstract: At high temperature, porous carbon can be easily oxidized, which limits its industrial applications in catalysis . In this paper, in order to increase the antioxidative ability of porous carbon, boron in solid state was added to porous carbon by KOH chemical activation. It has been proved that the antioxidative ability of porous carbon can be effectively increased by borondoping, because the quantity of active sites on the surface of porous carbon gradually reduced after the heat treatment, inhibiting the reaction between the oxidative gas and the porous carbon. When the content of borondoping is 10% in the porous carbon and the content of B4C is 25% in the borondoping， the relative weight loss of the porous carbon decreased from about 70% to about 20%, the surface area of the porous carbon decreased 10%～20%, Microreactive activation of the porous carbon still remained at 70.25 after 5h, borondoping treatment, comparing to the raw material at 600℃.
Abstract: Jetting characteristics, i.e., jet formation, jet development, bubble size, transient gas velocity field, transient voidage and spectral power density of pressure signals, have been investigated numerically in a gassolid fluidized bed by using a new model proposed by Brandani and Zhang. Simulation is carried out for a twodimensional fluidized bed of size 1.6m ×0.3m equipped with a jet of 0.01m width in the central bottom of the bed. Sand belonging to Geldart B Group is selected as solid material, whose diameter and density are 500mm and 2660kg/m3, respectively. Transient results show that there exist obviously axialasymmetric behaviors for the jet above the nozzle, the bubble after the jet collapse as well as the gas velocity field and the voidage profile in the whole bed. The spectral power density of pressure signals, however, keeps almost equal at the axisymmetric positions in the jetting fluidized bed. The conclusions mentioned above imply that the simulated results in the half bed can represent the characteristics in the whole jetting fluidized bed for a stable operation in the commercial process. It is obviously different between the transient characteristics in the half bed and those in the whole bed.
Abstract: Due to the advantages of high carbon conversion and high capacity, pressurized entrained flow gasification is of interest and becoming increasingly important in the production of synthesis gas. To improve the thermal efficiency, the entrained flow gasifiers often use twostage feeding mode. Recently, a novel pilot scale twostage entrained flow gasifier has been developed in China. In order to meet the requirements of the process development, a 3-D full scale(ID700mm×H11200mm) mathematics model based on the Computational Fluid Dynamic (CFD) has been developed for investigating the gassolid flow characteristics in the gasifier. In the model, the gas phase was treated as continuous phase with an Euler frame of reference, while the particle phase was modeled as dispersed phase with a Lagrange frame of reference. Base on this CFD model, a simulation was performed firstly under the base designing and operating condition, which gave the kinetics regulation of the gassolid twophase and the distribution of particle in the gasifier. And then a series of numerical simulations were performed under several different designing and operating conditions (the throat diameters and gassolid flow rate in the two stages) to investigate the effect of design and operation parameters on the gassolid flow throughout the gasifier. The results showed that throat diameter was critical in the twostage entrained flow gasifier, which might control the flow field, particle trajectory and particle distribution. The smaller throat diameter leads to not only stronger gas recirculation near the throat, swirling particle trajectories but also obviously changing of the particle distribution. The changes of feeding rate between the twostage obviously influence the gas flow flied and particle behavior. The feeding rate increase in the first stage and the decrease in the second stage will enhance the gas recirculation in the first stage, weaken the recirculation in the second stage and leads to stronger particle swirling up movement, higher particle concentration near the wall and less particle deposition at the bottom.
Abstract: The forms of oxygen in inertinite and vitrinite of Majiata coal were studied by means of X-ray photoelectron spectroscopy. The type and content of the oxygen were determined through analysis of spectrum for oxygen and carbon. The result indicates that the main type of oxygen forms in Majiata coal and its macerals is singlebond including ether link C-O and hydroxyl group O-H, then is carbonyl group and carboxyl group. Both the total oxygen content and the content of singlebond oxygen in inertinite are lower than those in vitrinite. The content of carbonyl group and carboxyl group in inertinite is higher than that in vitrinite.
Abstract: Three biomass wastes were studied with thermal analyzers. The pyrolysis characteristics were analyzed by using active and passive pyrolysis zone, and pyrolysis index. The pyrolysis kinetics parameters and controlling equations were derived from thermal gravimetric analysis. A general pyrolysis rate equation was deduced. The results show that pyrolysis of agriculture residues is not active in passive pyrolysis zone, but pyrolysis of wood residues is still active. Pyrolysis indexes increase with higher heating rate, which is beneficial to biomass pyrolysis. Pyrolysis of three biomass wastes conforms to two-stage model. Pyrolysis mechanism and kinetic parameters are different within different temperature range. For the same biomass sample, the main factors affecting the reaction rate are reaction kinetics parameters, while heating rate does not change the reaction rate equation but changes the reaction kinetics parameters.
Abstract: The nitrogen distribution in products during catalytic cracking of coker gas oil (CGO) was investigated in a laboratory twostaged riser catalytic cracking (TSRFCC) experimental unit with Kelamayi CGO as feedstock. The results showed that operation parameters, such as reaction temperature, catalystoil ratio and residence time, all could significantly affect the nitrogen distribution in the products. The nitrogen in the gas product and gasoline fractions decreased with the increase of reaction temperature and/or residence time, which could promote the thermal cracking. However, the nitrogen in gas product and gasoline fractions increased with the increase of catalystoil ratio, which could mainly enhance the catalytic cracking. On the whole, after CGO conversion, about 50% of the total nitrogen could produce nitrogen-containing coke over catalyst, and 20% of the total nitrogen remained in heavy oil, while only a little of the total nitrogen could be transfered into diesel, gasoline and gas products.
Abstract: γ-Al2O3supported molybdenum nitride, molybdenum phosphide and molybdenum carbide catalysts for hydrodesulphurization were prepared, respectively, by temperature-programmed reaction. The precursors were obtained by impregnation of γ-Al2O3 in an aqueous solution of ammonium heptamolybdate tetrahydrate [(NH4)6Mo7O24·4H2O] and diammonium hydrogen phosphate [(NH4)2HPO4], followed by drying at 120℃ and calcining at 500℃ in air. The three kinds of catalysts were characterized by XRD and BET. The results indicated that the molybdenum carbide prepared at a space velocity (CH4H2) of 10800h－1 has the biggest surface area of 175.7m2/g. The pore size distribution of molybdenum nitride catalyst was complex. The small pores of about 0.6225nm and the big pores of about 3.736nm were mainly observed in the supported molybdenum nitride catalyst. The active components in all of the three catalysts were dispersed on γ-Al2O3 uniformly. The conversion of dibenzothiophene on the three catalysts could respectively reach 85.5%、81% and 78.6%.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
