Abstract: In order to understand the mechanism of swelling and the relation between swelling behavior and solvent extraction, the swelling kinetics of residues from Shenhua coal extracted by CS2/NMP with different mixing ratios were studied in different solvents. The result shows that the swelling rates of extraction residues increase along with swelling temperature. The swelling rate in polar solvent NMP is much higher than that in nonpolar solvent THN. Solvent extraction has a great effect on the swelling of extraction residues. The swelling activation energy of extraction residues increases and the swelling rate decreases with the increase of extraction yield. The swelling activation energies of extraction residues in NMP and THN are less than 10kJ/mol, suggesting that the swelling process is controlled by solvent molecular diffusion in coal structure. Key words： coal; swelling; kinetics
Abstract: The slurryability of lignite and its mixture with different percent of petroleum coke have been investigated. It was found that only 41% of lignite water slurry could be obtained at 1000mPa·s due to the strong hydrophility and macroporosity of lignite. With petroleum coke, the solid content of lignite water slurry has been progressively improved. The more petroleum coke, the higher concentration of mixture slurry. The solid content of slurry is allowed to be 60% when the mass ratio of petroleum coke to lignite is 3 to 2. All coke-lignite-water slurries exhibit pseudo-plastic behavior and good static stability. The hydrophility of lignite is strong, while petroleum coke is hydrophobic. The complementarity of lignite and petroleum coke plays the key role in getting high mass fraction of cokelignitewater slurries.
Abstract: Release behaviors of Hg during pyrolysis of Jincheng (JC) coal, a Chinese anthracite, were studied under N2, CO2 and H2 atmospheres in a temperature-programmed unit coupled with an on-line atomic fluorescence spectroscopy. In all the atmospheres, Hg release starts at about 200℃ and increases with the increase of temperature. The release ratio (RR) of Hg is more than 95% at 1200℃, which is higher than the corresponding volatile yield. Carbon in coal may be a reducing agent during the Hg emission. Under N2 atmosphere, 97% of Hg is released as elemental form. Under CO2 and H2 atmosphere, however, only 73% of Hg is released as elemental form due to the restriction of the chemical equilibrium. H2 can promote the release of volatiles and increase the release rate of Hg, which decreases the contact probability of mercury compound with C and results in the reduction of elemental form Hg.
Abstract: For the development of a process of low temperature coal pyrolysis combined with CFBC, a hot moving-bed facility with a capacity 10kg/h of coal feeding was set up, in which high volatile bituminous coals pyrolysis by solid heat carrier was carried out. Two modifications were made in the new process. One modification is that the baffle mixing is used instead of agitated mixing; the other modification is that the granular bed is applied to the dust collection from pyrolysis gas. Compared with the fixed-bed experimental results in which coal and solid heat carriers are mixed by screw propeller, the baffle mixing is more effective. The effects of operating parameters on the dust collection of granular bed were investigated experimentally. It is concluded that the dust content in tar is reduced and the granular bed is suitable for the process of low temperature coal pyrolysis. In addition, the operating characteristics of the moving-bed system are discussed.
Abstract: The catalytic effect of single and mixed catalysts including two single catalysts with 3% Ca and 5% Na-BL, and one 3% Ca+5%NaBL mixed catalyst on carbon conversion, gasification reaction rate, relative amount of harmful pollutant like sulphur containing gases under temperature ranging from 750℃ to 950℃ and ambient pressure conditions were investigated by thermogravimetry in mixing (air/steam) gasification for three highmetamorphous anthracites of Longyan, Fenghai, and Youxia coals. The mixed BL+Ca catalyst has a synergetic effect in comparison with only using single BL and Ca catalyst. At mixing gasification the mixed catalyst of 3% Ca+5% NaBL greatly increases the carbon conversion and reaction rate by accelerating the reactions of C+CO2→2CO and C+H2O→CO+H2 because of the presence of alkali surface compounds \[COM\] and \[CO2M\], and exchanged calcium phenolate and calcium carboxylate (COO)2. This catalytic action is stronger than steam gasification. By adding CaCO3 into BL catalyst in gasification less than 900℃, the catalytic ability is improved with increasing coal conversion and effective desulphurization.
Abstract: The transformation behaviors of ironbearing minerals during O2/CO2 combustion of pulverized coal usere studied through combustion experiments of by burning wulanmulun coal and halagou coal in a drop tube furnace. 57Fe Mssbauer spectroscopy was employed to characterize and compare in detail the ironbearing components present in the ashes formed in O2/N2 and O2/CO2 combustion as well as those occurring in the parent coals. It was found that, in comparison with O2/N2 combustion, O2/CO2 combustion does not affect the ironbearing phases formed, however, it does affect their relative amounts in the ashes. O2/CO2 combustion favors the included pyrite and siderite to form ironcontaining glass silicates rather than oxidizing to form iron oxides. The changes of the relative amounts of the ironbearing phases in the ashes imply that O2/CO2 combustion may affect the potential of slagging. For the coals highly containing included ironbearing minerals, O2/CO2 combustion may enhance the slagging potential.
Abstract: Zirconium-containing mesoporous molecular sieve SO42-/Zr-MCM-41 was synthesized and used as a catalyst in upgrading bio-oil through reactive rectification. The suitable operation conditions for biooil upgrading were obtained as follows: catalyst usage based on biooil = 4%; reflux ratio = 1∶6; mass feed ratio of biooil ∶ethanol ∶ hydrogen peroxide (aqueous solution 30%) = 1 ∶ 0.5 ∶ 0.4. The yield of light oil was up to 21.4%. Under these conditions, two kinds of upgraded bio-oils (light oil and heavy oil) were obtained; their densities were reduced from the original 1.16kg/m3 to 0.91kg/m3 and 0.95kg/m3, water content from 33% to 0.5% and 5.0%, whereas, the gross calorific value increased from the original 14.3MJ/kg to 21.5MJ/kg and 24.5MJ/kg, and the pH value from 2.82 to 7.06 and 5.35, respectively. The volatile organic acids were converted into esters under the action of the solid acid catalyst SO42-/Zr-MCM-41, whereas, the heavy oil was composed of nonvolatile components in the original bio-oil.
Abstract: Effects of precalcination on catalytic activity of olivine in biomass gasification were investigated in a fixedbed reactor. The experimental results show that the catalytic activity of the olivine is improved by precalcination at higher temperature. The results of X-ray Diffraction (XRD), Local Scanning Electron Microscopy/Energy Dispersive X-ray Analysis (SEM/EDX), and Temperature Programmed Reduction (H2-TPR) indicate that the crystalline structure of the olivine is modified by the precalcination. The α-Fe2O3 formed on the surface of the precalcined olivine sample is due to the eduction of iron from the olivine structure (iron and magnesium orthosilicate) during precalcination. The distribution of Fe elements on the surface of the precalcined olivine particle becomes more uniform than that of the natural sample. The amount of reducible iron oxide on the surface of samples increases with the increase of precalcination temperature and time. It can be inferred that the increase of olivine catalytic activity after precalcination is attributed to the formation of α-Fe2O3. However, the antiattrition ability of the olivine particles decreases after precalcination at 800℃~1100℃. The optimal catalytic activity and anti-attrition ability can be obtained at the precalcination temperature of 900℃ for 4h.
Abstract: A six-lump kinetic model was derived on the basis of FCC reaction mechanism to represent the FCC naphtha reformulation for reducing olefin and enhancing propene production. Lumps were defined not only by their boiling range but also by their chemical compositions. Rate constants, frequent factors and activation energies parameters were estimated according to the experimental data. The proposed model could not only predict the yields successfully, but also provide more information about the chemical compositions of naphtha; which is useful for any attempts to reduce the olefin content in FCC naphtha and to enhance the propene production.
Abstract: The intrinsic and global kinetics of thiophene hydrodesulfurization over CoMo/Al2O3 catalysts were studied in an isothermal integral tubular reactor under the conditions of 543K~623K, 2.5MPa~3.5MPa and H2/oil mol ratio 2~4. The kinetic model was derived from the LangmuirHinshelwood mechanism and the kinetic parameters involved were estimated based on the experimental data. The kinetic model was verified by comparison of the experimental and predicted data as well as by statistical test. Moreover, the calculated Thiele modulus together with the comparison of the pore size distribution and the carbon content of the fresh catalyst with those of the deactivated catalyst revealed that the effect of the internal diffusion on the overall reaction rate was evident. The effectiveness factor was subsequently calculated from the intrinsic and global rates obtained above, and it showed that the effectiveness factor decreased dramatically with increased temperature, while the effect of H2/oil mol ratio was not evident.
Abstract: Pd-CeO2/Al2O3 catalysts with different Pd contents were prepared by stageimpregnation; their performances in hydrodesulfurization (HDS) of thiophene were investigated. XRD, H2-TPR, NH3-TPD, hydrogen and CO chemisorption were used to characterize the catalyst structure. The results show that Pd precursor is deposited favorably on CeO2 surface; new acid sites are produced due to the interface effect from the PdCe interaction. The highest promoting effect of Pd-Ce interaction is observed on the Pd-CeO2/Al2O3 catalyst with a Pd content of 2%, which exhibits highest interface acidic amounts per unit Pd. Pd(111) face is the predominant face, which brings on the strong PdCe interaction and interface effect. As to PdCeO2/Al2O3 catalysts with 1% and 4% Pd content, the space structure of Pd-Ce interaction inhibited the interface effect; hence the promoting effect was not so distinct.
Abstract: The effects of reaction parameters such as temperature, pressure, and hydrogen to hydrocarbon ratio (H2/HC) on the hydroconversion of methylcyclopentane (MCP) over Pt/HZSM-5 have been investigated in a fixedbed downflow reactor. The catalytic evaluation results were compared with the thermodynamic calculation data in order to investigate the behavior of MCP Ring enlargement (RE) reaction. Methylcyclopentane hydroconversion is described as a linear combination of three reactions: ring enlargement (RE), ring opening (RO) and cracking (CR), and RE reaction produces cyclohexane (CH) and benzene (Bz). It was shown that the conversion of MCP increased with the increase in temperature or with the decrease in H2/HC mol ratio, whereas decreased with the increase of pressure. The influence of the reaction parameters on the RE selectivity presented a complicated picture. With the increase in temperature, the RE selectivity first increased and then decreased, showing a maximum at a certain temperature. The effect of the H2/HC mol ratio was found to be relevant with temperature. At lower reaction temperatures, the RE selectivity decreased with decrease in the H2/HC mol ratio. However, at higher reaction temperatures, the H2/HC mol ratio had little influence on RE selectivity. The distribution of RE products between CH and Bz provides information on the reaction pathway. The experimental Bz/CH ratio was in excess of the equilibrium value, which strongly suggested that Bz, as the same as CH, could be a primary product from MCP. Thus, a modified reaction pathway of RE reaction could be proposed as follows: both CH and Bz were produced from the same intermediate, which was an adsorbed species on the dual function catalyst formed from MCP. In other words, the isomerization and dehydroisomerization are parallel reactions, producing CH and Bz, respectively. Meanwhile, Bz can come from CH through dehydrogenation.
Abstract: The methane reduction behavior was studied in a molten alkali carbonates (Li2CO3、Na2CO3、K2CO3) system. Thermodynamic and experimental investigations were performed to quantify the product compositions. The results showed that the CO and CO2 contents in the product gases increased with the reaction temperature, whereas it decreased with the reaction time. The reaction activity order of carbonates was Li2CO3 > Na2CO3 > K2CO3. The selectivity of CO in the mixed molten salts system was higher than that in a pure system. The mixed molten salts system was more suitable than pure system as the reaction medium of CH4 conversion. H2 was mainly from the CH4 cracking, and CO and CO2 was from the reaction between CH4 cracking carbon and molten alkali carbonates.
Abstract: Pd/HZSM-5 coating was prepared on the inner wall of φ3 tubular reactor by gas-aided fluid displacement and electroless plating technologies. The coating was characterized by means of SEM, XRD, and XPS. The coating surface was flat without flaws, with thickness of 12μm~16 μm and catalyst particle of size 1μm~5μm. Metallic Pd particles were uniformly dispersed on the coating surface. The coating was used as the catalyst for the supercritical cracking of n-dodecane, a typical model compound of endothermic fuel. With the temperature of 640℃, pressure of 4MPa, and resident time of 10s, Pd/HZSM5showed very high cracking ratio of 55.5%, hydrogen yield of 3.1%, and heat sink of 3470kJ/kg, which were increased by 8.5%, 58.7%, and 10.5% compared with HZSM-5 coating, respectively. Furthermore, they were 17.3%, 78.1%, and 13.5% higher than the case of thermal cracking reaction, respectively.
Abstract: Both silverloaded activated carbon fibre (silver-loaded ACF) with the silver content of 14.07% and activated carbon fibre (ACF) in form of sheet shape were tested to get their saturation adsorption capacities for mercury in a nitrogen stream. Results showed that silver-loaded ACF and ACF had a saturation adsorption capacity of 192.3mg/g and 29.4mg/g at 70℃, which was 48~192 and 7~29 fold that of common activated carbon, respectively. The thermal desorption characteristics of elemental mercury of the two sorbents were investigated by thermogravimetric analysis (TGA). Mercury desorption from silver-loaded ACF occurred in the temperature range of 100℃~650℃, and mercury desorption efficiency was 94.73% as temperature increased from 50℃ to 650℃ within 70min. Mercury desorption from ACF occurred in the temperature range of 100℃~230℃, and mercury desorption efficiency was 69.93% as temperature increased from 50℃ to 350℃ within 40min. Both silver-loaded ACF samples undergoing mercury adsorption and thermal desorption run were analyzed by scanning electron microscope (SEM). Results showed that after mercury adsorption run, the silver enriched in silver amalgam particles and intensively distributed on the junctures of ACF microcrystals. And after thermal desorption run, the enriching silver got to dispersedly distribute on the surface of ACF in form of globular particles in submicronsize or nanosize. The SEM micrographs of ACF after mercury adsorption and thermal desorption run showed that the elemental mercury by physical adsorption disappeared but mercuric oxide particles by chemical adsorption had a little increase. It suggested that elemental mercury can easily be removed by thermal treatment but mercuric oxide can't be removed. Parts of elemental mercury might transform to mercuric oxide during thermal desorption run.
Abstract: To enhance SO2 absorption rate and removal efficiency, hydrogen peroxide as a strong oxidant was added during the spray water humidification in the process of semi-dry flue gas desulfurization. The effects of hydrogen peroxide concentration, Ca/S mol ratio and approach to the saturation temperature on the SO2 removal efficiency were investigated. The results show that SO2 absorption rate can be significantly enhanced with hydrogen peroxide; when the lime particles are humidified by a hydrogen peroxide solution of 1.0% to 2.0%, the SO2 removal efficiency increases about 20% to 30%. Moreover, SO2 absorption rate and sorbent utilization increase with the hydrogen peroxide concentration.
Abstract: The simulation of producing acetone and methanol from water phase product of Fischer-Tropsch synthesis was carried out by the software of ASPEN PLUS(model version 11.1). Under different conditions, the simulation and optimization of the distillation columns were made and the optimal operation parameters of the whole process were obtained. Extractive distillation column: the volume ratio of solvent to feed is 1.00, the mass ratio of distillation to feed is 4.56%, the reflux ratio of mass is 2.00, the numbers of theory stage of extractive distillation column is 36, the numbers of solvent stage of extractive distillation column is 8 and the numbers of feed stage of extractive distillation column is 18, the optimal temperature of feed is 325.15K and one is 328.25K for the solvent water. Solvent recovery column: the mass ratio of distillation to feed is 42.10%, the reflux ratio of mass is 1.00, the numbers of theory stage of solvent recovery column is 19, and the numbers of feed stage of solvent recovery column is 13. Through the comparison of data between simulation and experiments, the reliability of simulation was testified.
Abstract: Micrometer-sized TS-1 has been modified with tetrapropylammonium hydroxide (TPAOH) solution. The effects of modification conditions, including temperature, time and concentration of TPAOH, on the catalytic properties of TS-1 in the hydroxylation of phenol and ammoxidation of methyl ethyl ketone (MEK) were investigated. The modified samples were characterized with XRD, SEM, TEM, UV-Vis and FT-IR techniques and N2 adsorption experiment. It was shown that the structure of TS-1 was basically unchanged after the modification, but etching occurred, as proved by the presence of a number of small caves in the modified samples. The optimum modification condition was as follows: TPAOH concentration of 0.15mol/L, time of 48h and temperature of 170℃. The sample modified under this condition showed a significant improvement in the catalytic performances in the hydroxylation of phenol and ammoxidation of methyl ethyl ketone.
Abstract: In order to understand the volatile behavior of Pb in oil shale, the pyrolysis tests were performed in laboratory with a bulk of oil shale from Huadian and Wangqing. The content of Pb in samples was determined using the inductively coupled plasma atomic emission spectroscopy (ICP-AES). The influence of different factors on the volatility of metal Pb was analyzed, and sequential chemical extract process was used to examine the occurrence of Pb. The results show that Pb of oil shale mainly exists in the forms of the sulfide and the stable state. The content of Pb in these two conditions accounts for 74.08%~79.78%. At the same time, the volatility of Pb can be affected not only by the volatility of the individual element and its compounds, but also by the occurrence, pyrolysis temperature, heating rate, and pyrolysis atmosphere. With the temperature increasing, the volatility of Pb increases. The reduction atmosphere is favorable to the volatility of Pb than the oxidizing one.
Abstract: SbSn intermetallic compound was prepared via mechanical alloying with equal molar ratio of Sb to Sn. The bulk phase structure, micromorphology, melting point and particle size of the SbSn alloy were determined by XRD, SEM, DSC and granulometer respectively. The average diameter of SbSn alloy particle is 10.622μm after 36h ball milling. The SbSn was supported on wire net as working medium, and its desulfurization behavior for four W/O emulsion of crude oil was investigated in an directcurrent field. Under the condition of temparature 30℃, surfactant addition 0.19%, desulfurization efficiency reached 36.8% for W（40）/O（60） when voltage was assigned at 9.62V and processing time was 22h. The desulfurizaition mechanism could be explained by that there are electrochemical reactions between P-polar formed by Sb which is enriched on SbSn surface and the negative polar sulfide on condition of electric current being induced. The electrochemical determination showed that the reaction of sulfur on SbSn surface is reversible.
Abstract: The catalytic performances of monolithic catalyst Ru/Al2O3/Cordierite in selective hydrogenation of benzene to cyclohexene were examined in a circulated monolithic fix-bed reactor. The monolithic catalyst exhibited excellent performances in the selective hydrogenation of benzene to cyclohexene; a high cyclohexene yield of 18% was obtained. The addition of aqueous solution of ZnSO4 during reaction was important to obtain high cyclohexene selectivity. The results indicated that both the catalyst with high activity and selectivity and the intensification of external diffusion for cyclohexene were crucial to get high cyclohexene yield.
Abstract: A series of CuZnAl slurry catalysts were prepared by the complete liquidphase technology. The influence of heat treatment atmospheres with different proportions of CO2 on the performance was investigated and the catalysts were characterized by TPR, BET, XRD and XPS. The results show that introduction of CO2 into heat treatment atmosphere influences obviously on the structure of catalysts before reaction but less on that of the ones after reaction.The reason is under the conditions of reaction, the bulk structure, pore structure and surfa ce state will voluntarily go to same. The heat treatment atmosphere with different content of CO2 influences obviously on the reductive performance of the catalysts, low reductive temperature is corresponding to high DME spacetime yield and right amount of Cu metal and Cu2O to high CO conversion. The introduction of CO2 into heat treatment atmosphere restrains the watergas shift reaction, raising the DME selectivity. The proper amount of CO2 in the heat treatment atmosphere can result in the increase of DME space-time yield. In this work, when the content of CO2 in the heat treatment atmospheres is 50%, the performance of catalysts is best.
Abstract: The effect of HF treatment on etherification activities of ZSM-5 zeolite was investigated. Appearance, crystal structure, pore structure, acid quality of treated zeolite was charactered. It was found that catalyst treated by HF remained typical MFI structure, but grain broken; pore volume and average pore diameter of treated zeolite increased obviously; Bronsted acid quantity decreased; etherification activities of fluorinate treatment of ZSM-5 zeolite increased obviously.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
