Abstract: Based on coal gasification combined with methane reforming process, the reaction of methane and carbon dioxide was investigated over quartz sand, coal ash and char, respectively, in a fixed bed system. It was proved that coal char has distinct catalytic effect on methane conversion during the coal gasification combined with methane reforming process. Other experiments were carried out with sets of operation conditions including temperature ranging from 1073K to 1223K , the inlet CH4/CO2 ratio increasing from 0.33 to 3.00 and the gas-solid contact time varying from 0.13(g·min)/mL to 1.04(g·min)/mL. The results show that methane conversion increases with increasing temperature and gas-solid contact time, but decreases with increasing CH4/CO2 ratio. The highest methane conversion rate can get 86%. H2/CO ratio in the product gas can be adjusted from 0.4 to 2.0 through changing the reactants' ratio of CH4/CO2.
Abstract: Quick coal liquefaction at high temperature (QCLHT) was studied by using a 17mL tubular resonance agitation microautoclave reactor. The results show that a low rank bituminous coal containing little mineral matter exhibits good liquefaction performance. The conversion is mainly influenced by hydrogen-donating ability of solvent and contribution of H2 is negligible. The conversion under N2 atmosphere is basically equal to that under H2 atmosphere. Effect of catalyst is not remarkable. Coal particle size has little influence on conversion, whereas vibration of reactor has important influence. Based upon the above conclusions, the reaction mechanism of QCLHT was suggested. At high temperature zone of the primary pyrolysis of coal, usually near 500℃ or so, bridge bonds in its structure are sufficiently broken for low rank bituminous coal, and large amounts of free radicals are thus formed. If enough excellent hydrogen donor solvent is used as hydrogen source, the free radicals could be stabilized and formed into liquid product. Hence, rather high conversion is achieved within dozens of seconds or a few minutes.
Abstract: Thermogravimetric analyzer (TGA) was employed to evaluate the combustion behaviors of Xuzhou bituminous coal and its char in different atmospheres, and the effects of O2 concentration, CO2 concentration and particle size on the combustion characteristics were analyzed. Results show that the atmosphere does not affect the beginning time of devolatilization, but significantly affect the combustion rate and the burnout time. Higher concentration of CO2 can increase the burnout time obviously. However, the atmosphere does not influence the combustion kinetics mechanism. Increasing the O2 concentration, decreasing the CO2 concentration and reducing the sample particle size are beneficial to the improvement of the combustion characteristic, while the improvement degree for coal is more obvious than that for char. SEM analysis indicates that the ash surface after O2/CO2 combustion is looser and more porous than that after air combustion.
Abstract: In this study, the kerogen of oil shale from Moroccan Tarfaya deposits was isolated and the changes in the initial organic matter during the removal of the mineral matrix were examined. Chloroform extraction of the oil shale increases the intensity of the peaks in the X-ray diffractograms. Infrared spectra and X-ray diffractograms reveal the presence of mineral, calcite, quartz, kaolinite, and pyrite in the mineral matrix of the oil shale. Hydrochloric and hydrofluoric acids dissolution do not alter the organic matter. The nonisothermal weight loss measurements indicate that thermal decomposition of the isolated kerogen can be described by firstorder reaction. A single kinetic expression is valid over the temperature range of kerogen pyrolysis between 433K and 873K. Furthermore, the results indicate that the removal of mineral matter causes a decrease in the activation energies of the pyrolysis reactions of oil shale.
Abstract: The influence of acid-washing pretreatment on biomass pyrolysis was experimentally studied in a radiation reactor. The results show that the metal ions content of rice husk treated by acids is reduced markedly. The yield of tar from pyrolysis of rice husk treated by 7% HCl increased from 41.74% to 52.88%, and the yields of gas and char decrease. The influence will be more remarkable with the increase of acid concentration. The gaseous products of pyrolysis of HCl-treated rice husk mainly consist of CO and CO2 which yields decreased metal ions content when compared with those of the raw sample. The effects of H2SO4, HCl, and H3PO4 on biomass pyrolysis are different. HCl has the strongest effect on the pyrolysis products distribution because of the least amounts of K+ remained after HCl treatment. The microstructures of biomass are damaged seriously by H2SO4 treatment.
Abstract: Pyrolysis properties of three manure samples were investigated using TGA and XRD. H2 was produced from them by low temperature catalytic gasification process using a two-stage fixed-bed reactor. The drastic increases in the pyrolysis conversion of the manure samples was observed in 473K~823K. During the main pyrolysis stage, pig manure samples experienced two distinct weight-loss stages and only one peak was observed in the DTG curve of hen manure sample. The difference between their pyrolysis behaviors may be due to the difference in the organic materials. XRD results show that hen manure includes lots of Ca species in the form of CaCO3 which is converted into CaO during pyrolysis. Ni/Al2O3 catalyst promotes the tar cracking into little molecules and the volatile matters are converted into H2, CO, CH4, CO2 and carbon completely. High yields of H2 and CO are obtained in low temperature catalytic gasification. These results provide a theoretical foundation on the development of low temperature gasification process for manure management.
Abstract: Bio-oil produced from biomass by fast pyrolysis is mainly composed of oxygenated organics and contains high content of water, which makes it unsuitable for direct use as fuel. By developing emulsions from diesel and bio-oil, however, the bio-oil can then be used in compression ignition engines. In this work, the emulsions from diesel and bio-oil are produced by using ultrasonic emulsification method. The physicochemical properties of the emulsions were measured, including density, viscosity, flash point, smoke point, freezing point, and gross heating value. The optimum hydrophilic and lipophilic balance (HLB) value of the emulsifier and the influence of emulsification conditions on the emulsion stability were investigated. The results show that the optimum HLB value of the emulsifier for the emulsification of diesel and bio-oil is about 5.5~6.2; the most stable emulsions are then obtained when the emulsification is conducted at 50℃~60℃ and with the input work of 180J/mL~300J/mL. With the increase of bio-oil content in the emulsions, the density, viscosity, flash point and smoke point of the emulsions are increased, while their freezing point and gross heating value are decreased.
Abstract: The bio-oil from fast pyrolysis of biomass has chemical instability and high viscosity and is difficult to be emulsifid with 0# diesel. Surrounding these problems, an emulsification process, the bio-oil aqueous solution was emulsified with 0# diesel, is suggested. Four common emulsifiers and one co-emulsifier were selected and remixed to two new emulsifiers. Under certain conditions, the effect of two remixed emulsifiers, the mass ratios of remixed emulsifiers and the ultrasonic time on emulsification results were studied. The results show that the six emulsions are not broken within 30d. Compared with characteristics of 0# diesel, its density and heat value are almost the same, water content is below 3%, kinematical viscosity increases about 40%, and pH value decreases about 50%. Factor analysis shows that mass ratio of bio-oil aqueous solution to diesel and different types of bio-oil aqueous solutions are most important to influence on the emulsification. The emulsification mechanism was preliminarily discussed. Polar compounds such as water, aldehyde, acid and ketone from bio-oil aqueous solution were wrapped in W/O emulsion droplet. The compounds such as ethyl acetate and aromatic compounds were solubilized in the micelles of the nonionic emulsifiers. The thermodynamic analysis on emulsification shows that entropy increase of ultrasonic emulsification process is more than that of static biooil, and the emulsions tend to be equilibrium state.
Abstract: The ionic liquid \[BMIM\]\[AlCl4\] was synthesized to upgrade heavy oils. The influences of contents of sulfur and water, reaction temperature, and transition metal salts on upgrading heavy oils were investigated. The experimental results show that a certain amount of sulfur in heavy oils is beneficial to the viscosity reduction. The reduction of viscosity by \[BMIM\]\[AlCl4\] ionic liquid is better when the water content of heavy oils is less than 10%. The optimum temperature to upgrade the Xinjiang heavy oil with \[BMIM\]\[AlCl4\] ionic liquid is 65℃~85℃. The combination of transition metal salts and \[BMIM\]\[AlCl4\] can enhance the viscosity reduction in heavy oils. More than 60% of viscosity can be reduced by treating the heavy oil with the mixture of \[BMIM\]\[AlCl4\] and NiNaph, and in addition, the asphaltene content can be reduced by 78%.
Abstract: Dihexadecyl fumarate-styrene copolymer (FOS) was synthesized by solution free radical copolymerization with benzoyl peroxide as the initiator. The monomer dihexadecyl fumarate (DHF) was obtained by direct esterification of fumaric acid and hexadecyl alcohol using paratoluenesulfonic acid as catalyst, hydroquinone as polymerization inhibitor and toluene as solvent. FOS obtained was then evaluated as a cold flow improving agent for diesel fuel. Zhangjiagang 0# diesel and Shengli Haike 5# diesel were used. The structures of monomer and copolymer were characterized by IR and 1H-NMR and the composition of diesel oils was analyzed by gas phase chromatography. The effects of FOS on the cold filter plugging point (CFPP) and the depression mechanism were then investigated. The results indicated that the copolymer FOS obtained in this work can be used as the cold flow improver for diesel fuel. The CFPP values of Zhangjiagang 0# diesel and Shengli Haike 5# can be depressed by 6℃ and 3℃, respectively, by adding 0.1% FOS in the diesel oils. The sensitivity of FOS as cold flow improver may vary for different diesel products. When mixed with two kinds of commercial cold flow improvers, FOS exhibits excellent performance and good application prospects as the diesel oil additive.
Abstract: The amorphous Ni-Mo-B catalysts were prepared by ultrasonic as well as regular chemical reduction and characterized by BET, SEM, XRD, XPS, and FT-IR. Their catalytic activity in the hydrodeoxygenation of phenol was evaluated. The influences of the catalyst preparation conditions and the reaction temperature on the phenol hydrodeoxygenation were investigated, and a reaction mechanism was proposed. The results showed that the particle size, agglomeration phenomenon, surface area, and MoO2 and B content of the Ni-Mo-B catalysts can be regulated by introducing the ultrasonic treatment into the chemical reduction, which is effective to enhance their catalytic activity in phenol hydrodeoxygenation. At 498 K, the conversion of phenol is 81.08% and the hydrodeoxygenation selectivity reaches 93.39%.
Abstract: Ni/ZnO catalyst prepared by impregnation and co-precipitation methods for ultra-deep hydrodesulfurization of benzene was studied. The structures and properties of the catalysts were investigated by H2-TPR, XRD and BET techniques. It was found that the interaction between NiO and ZnO has important influence on the activity and selectivity of the catalysts. NiO with weak interaction with ZnO has high benzene hydrogenation activity after reduction by H2, resulting in conversion of benzene to cyclohexane, whereas, NiO with strong interaction with ZnO has hydrodesulfurization activity, but has no benzene hydrogenation activity. The catalysts prepared by impregnation showed certain content of weak-interaction NiO, so the benzene exhibited great lose. The NiO, prepared by co-precipitation, has strong interaction with ZnO，so the catalyst has better selectivity toward desulfurization. Furthermore, the catalyst prepared by co-precipitation had a higher BET area. As a result, the activity and selectivity were higher over catalyst prepared with co-precipitation than that over catalyst prepared by impregnation. It was found that reduction temperature has important influence on catalyst activity and selectivity. Catalyst reduced at 400℃showed the best performance while reduction at 500℃ resulted in the decrease of the activity due to crystal particles sintering and specific surface area decrease. Addition of Sn can change the interaction between NiO and ZnO. Due to the inhibition of formation of weakinteraction NiO, Sn addition suppressed greatly the loss of benzene.
Abstract: A series of silica supported MoP (MoP/SiO2) catalysts with different Mo loadings were prepared by sol-gel method, followed by temperature programmed reduction treatment. The hydrodesulfurization (HDS) activity of the MoP/SiO2 catalysts was evaluated with thiophene and dibenzothiophene as model compounds. The influences of Mo loading, reaction pressure and temperature on the HDS activity were investigated. The catalysts MoP/SiO2 exhibit high activity for the HDS of thiophene and dibenzothiophene; the highest activity is observed over MoP/SiO2 with a Mo loading of 20%. An elevation of the reaction pressure or temperature can enhance the HDS of dibenzothiophene; however, it may also decrease the content of biphenyl in the products.
Abstract: A set of lumped kinetics models were developed from two kinds of F-T reaction mechanisms inspired on the basis of study on quantum chemistry in reference. The experimental data were measured in a continuous stirred tank reactor with an industrial FeMn catalyst. It is concluded that the optimized model in analogy with the one in reference was derived from the mechanism of hydrogen assisted dissociation of CO through its oxygenate intermediate.
Abstract: The composite ZSM-5/SAPO-5 molecular sieves were synthesized by two-step hydrothermal crystallization process. The effects of the mixing manner of the ZSM-5 gel and SAPO-5 gel, the acid type used to adjust the pH value of ZSM-5 mother solution, the composition of SAPO-5 gel, and the crystallization time on the synthesis of the composite were investigated. The results showed that the composite could not be obtained by simple mixing of two synthesized gels. The composite was successfully synthesized when the pH value was adjusted by sulfuric acid solution, the mass ratio of ZSM-5/SAPO-5 was 3.5 and the P2O5/Al2O3 molar ratio in the SAPO-5 gels was 1.2. The composite material contained small amount of amorphous substance, which could not be eliminated completely by extending the crystallization time.
Abstract: Beta zeolites with the SiO2/Al2O3 molar ratio of 30 and 150 were synthesized in an extremely dense aqueous system by using tetraethylammonium hydroxide (TEAOH) as template and solid silica gel as silica source. Meanwhile, another beta zeolite sample of high SiO2/Al2O3 ratio (about 150) was obtained by dealuminization of the low SiO2/Al2O3 ratio (30) zeolite in an oxalic acid solution at 70℃. All three zeolites samples were characterized by XRD, SEM, N2-adsorption and pyridine adsorption IR spectrum. The effects of their addition on the performances of a hydrocarbon cracking catalyst were investigated in a microactivity test (MAT) unit at 460℃. The results indicated that the intrusion of zeolite beta into the cracking catalyst can enhance its catalytic activity and improve the product distributions. When the zeolite beta of low SiO2/Al2O3 ratio was added in the cracking catalyst, the isomerization was promoted and the selectivity to ethene and propene was increased. On the other hand, the addition of high SiO2/Al2O3 ratio beta zeolites or the dealuminized one was able to enhance the aromatization of olefins, to increase the C4 olefin yield and to lower the carbon deposition during reaction.
Abstract: The deactivation of binderless 5A molecular sieves for the adsorption-separation of normal hydrocarbons was investigated on a fixed bed adsorber. The deactivated molecular sieves were regenerated by removing the coke deposited through oxidation under various conditions. The deactivated molecular sieves exhibited lower surface area (ABET), smaller pore volume (vp) and larger pore diameter (dp) than the fresh sample, because certain passages in the molecular sieves were blocked by the coke deposited. With the increase of the coke content in the molecular sieves, the deactivation rate decreased gradually. With the increase of oxidation temperature from 582K to 787K, the coke removal efficiency was elevated from 64% to 100%. At 787K, coke deposited in the molecular sieves was completely removed and the adsorption activity of the molecular sieves was recovered; however, ABET and vp of the regenerated molecular sieves could not be restored to the original values of the fresh samples. Under 685K~884K, the removal of coke from the binderless 5A molecular sieves by the oxidative treatment could be expressed with a macrokinetic formula：ln(C0/C) = 0.013exp(-28122.1/T) (pO2)0.32t.
Abstract: A blended solution based on amino acid salt was presented as a CO2 absorbent. Coupling process of a membrane contactor and the blended solution was investigated. The performances of the blended solution were experimentally compared with the single amino acid salt solution. Effects of various factors such as gas and liquid flow rates on CO2 concentration at gas and liquid outlets, capture efficiency, and overall mass transfer coefficient were discussed. A resistance in series model was developed to predict the overall mass transfer coefficients. Results show that performance of the blended solution is evidently better than that of the single solution. The blended solution can give lower CO2 concentration at gas outlet and higher CO2 concentration at liquid outlet as well as higher capture efficiency when compared with the single solution. The overall mass transfer coefficient with the blended solution is much higher than that with the single solution. The blended solution is confirmed to be an efficient absorbent for CO2 capture in membrane gas absorption. Model values are in good agreement with the experimental values.
Abstract: Single-step synthesis of bifunctional mesoporous solid acid materials SBA-15-SO3H－(CH3)x containing different hydrophobic alkyl (methyl, dimethyl or trimethyl) was carried out by hydrothermal treatment of gels. The catalysts were characterized by XRD, N2 adsorption, elementary analysis, and were tested in the esterification reaction of acetic acid with ethanol. The results revealed that the hydrophobicity of the as-prepared materials increased with the increase of methyl number of hydrophobic precursors, and the catalytic activity increased with the hydrophobicity of the materials. Among these materials, SBA-15-SO3H－(CH3)3 showed good performance toward the esterification reaction. Effects of reaction temperature, catalyst amounts, reaction time and the molar ratios of acetic acid/ ethanol over the catalyst SBA-15-SO3H－(CH3)3 were also studied. Under the optimal reaction conditions of temperature 120℃, n(acetic acid)∶ n(ethanol) = 4∶1, catalyst 1%, time 1h, the conversion of ethanol and the selectivity of ethyl acetate were 93% and 100%, respectively.
Abstract: Na-X zeolite (ZFA) was successfully synthesized from coal fly ash (CFA) through NaOH fusion and hydrothermal treatments and used to remove Ni2+ in waster water. To obtain the optimum conditions of Ni2+ sorption on the ZFA, the influence of operation conditions like solution pH value, adsorbent dose, contact time, Ni2+ ion concentration and adsorption temperature was investigated. The results showed that the ZFA obtained in this work is comparable with the 13X zeolites synthesized from chemicals in the efficiency of Ni2+ removal from wastewater. More than 90% of Ni2+ could be removed by ZFA from the waste water with initial Ni2+ concentration of 20mg/L~150mg/L at 20℃, solution pH value of 6, sorbent dose of 10g/L, and contact time of 15min. The adsorption of Ni2+ on the ZFA fits the Langmuir isotherm well; its monolayer adsorption capacity reaches 11.2×10-3 at 20℃. ZFA exhibits good regenerability and its removal efficiency for Ni2+ does not decrease within five recycles.
Abstract: The combustion characteristics of sludge samples including paper mill sludge, lake sludge and tannery sludge were investigated by using thermogravimetric analysis(TGA). The sludge tested had high volatile, high ash and lower calorific value. The results show that the combustion process of sludge can be divided into two stages. The first stage is the release and combustion of the volatile matter in sludge, and the second is the combustion of the fixed carbon. The weight loss for both combustion of volatile and fixed carbon for tannery sludge is almost equal, while the weight loss by the combustion of volatile accounts for more than 70% of total for lake sludge and paper mill sludge. It is indicated that the main combustible matter in sludge is the volatile matter, and the volatile is combusted in a wide temperature region (from 200℃ to 600℃). The overlapping phenomenon of peaks of the weight loss during the combustion reflects the complexity of the volatile matter in the sludge. Moreover, the reaction kinetics of the combustion of sludge was studied by the integration method of CoatsRedfern.
Abstract: A better insight into pressure signals could be helpful for the understanding of bubble behaviour as well as for the designing and manipulating of the gas-solid fluidized beds. Pressure fluctuations were measured in a rectangular fluidized bed with a height of 2.0m and a width of 0.3m by using a multi-channel pressure data acquisition system. Resin, belonging to Geldart B Group, was selected as experimental solid material. The characteristics of the pressure fluctuation were explored, and influences of superficial gas velocity and static bed height on the pressure fluctuation, pressure wave velocity and pressure fluctuation major frequency were investigated by using the standard deviation and the auto- and cross-correlation functions. The results show that the bubble behaviours such as formation, development, coalescence and break-up are major influence factors for the pressure fluctuation in the fluidized bed. The amplitude of pressure fluctuation near the interface between the dense phase and freeboard is governed by the bubble eruption. Pressure wave propagates within the bed and the pressure fluctuation signals along the bed height have obvious periodic characteristics in nature. Moreover, the pressure fluctuation, pressure wave velocity and main frequency are greatly dependent on the superficial gas velocity and the static bed height.
Abstract: The up to date research progress of the processing technology for Fischer-Tropsch syncrude were reviewed. The review emphasized on the processes of olefins oligomerization, hydrodeoxygenation, waxes hydroprocessing and hydrocracking according to the properties of Fischer-Tropsch syncrude. The characteristics of Fischer-Tropsch syncrude and processing technology were summarized and a few suggestions about the processing of Fischer-Tropsch syncrude in future were proposed.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
