Abstract: A Chinese lignite Yitai (YT) was pretreated by pyridine vapor and pyridine solvent. The effects of the treatments on the pyrolysis behavior of the pretreated coals were studied by thermogravimetric mass spectrometry (TG-MS). The results showed that both treatments could suppress the crosslinking reactions (CLRs) during pyrolysis of the treated coal, but the suppressing temperature range and mechanism were different. Some inherent hydrogen bonds (HBs) in the coal were broken by pyridine vapor treatment and new stronger N—OH HBs were formed. Thus, low temperature CLRs (below 400℃) that were related to the hydrogenbonded COOH—COOH and COOH—OH were suppressed. However, pyridine solvent pretreatment influenced the pyrolysis behavior by reducing the association interactions between the low molecular weight compounds and macromolecular network, thus, relaxing the threedimensional network of coal and enhancing the transmission efficiency of hydrogen in coal.
Abstract: The correlation between trace elements and coal-forming environment in the 6# coal from Junger coalfield has been studied with correlation analysis method. The result shows that there is obvious rule of trace elements separation in the coal facies. The most of “light elements” including IA, IIA and B groups of the forth period in periodic table are sensitive to the index of V/I and GI. The most of “heavy elements” such as elements after ones of IIIA and B groups of the fifth period in periodic table are sensitive to OI and BI index. Other elements are respectively correlated with TPI, VI, GWI and TI index. In a word, there is a trend in trace elements sensitive from V/I or GI to OI or BI when they are changed from light one to heavy, from low rank period to high and from low order A elements to high one.
Abstract: Conversions of 3 coal tars and their fractions in supercritical water (SCW) were investigated using a batch reactor. The results indicate that the conversion of the coal tar which has the highest content of asphaltene can obtain more lightproduct compared with the other two coal tars. It is also noticed that asphaltene is the main active component and it converts to maltene, gas and char in SCW. Compared with pyrolysis in N2, the conversion of asphaltene to maltene is enhanced while the formation of gas and char is restrained in SCW. Based on analysis of pyrolysis product, it is deduced that aromatic nucleus of asphaltene molecule is mainly composed of 1～4 rings aromatic compounds. Moreover, less than 10% of maltene fraction converts to gas, asphaltene and char. The fraction of char is very stable in SCW. Reaction pathway of coal tar in SCW is proposed from the reaction property of each fraction.
Abstract: For the production of hydrogen from lignite, a Supercritical Water (SCW) reactor with a coal feed rate of 1kg/h was set up, which was operated with continuous feeding of coal water slurry. The effects of reaction temperature (500℃～650℃), pressure (20MPa~30MPa), slurry concentration (20%~50%) and catalyst loading amount (0%~1% of coal) on the hydrogen generation characteristics were investigated. It is found that there is a notable increase in the hydrogen content and yield with the elevation of the reaction temperature. The hydrogen concentration and yield increase from 11% and 25mL/g coal to 29% and 110mL/g coal when the temperature increases from 500℃ to 650℃. The formation of methane is favored with the increase of reaction pressure. However, the carbon gasification rate and hydrogen yield decrease with the increase of slurry concentration. Moreover, the addition of 0.5% KOH can greatly improve the hydrogen production from high concentration coal water slurry. It is indicated that the reaction temperature and catalyst loading amount have a significant influence on the coal conversion and hydrogen yield, while the effect of pressure is relatively less significant.
Abstract: The online upgrading process that combined the fast pyrolysis of biomass and catalytic cracking of bio-oil was developed to produce a high quality liquid product from the biomass. The installation consisted of a fluidized bed reactor for pyrolysis and a packed bed reactor for upgrading. The proper pyrolysis processing conditions with a temperature of 500℃ and a flow rate of 4m3·h-1 were determined in advance. Under such conditions, the effects of temperature and weight hourly space velocity (WHSV) on both the liquid yields and the oil qualities of the online catalytic cracking process were investigated. The results showed that such a combined process had the superiority of increasing the liquid yield and improving the product quality over the separate processes. Furthermore, when the temperature was 500℃, with a WHSV of 3h-1, the liquid yield reached the maximum and the oxygenic compounds also decreased obviously.
Abstract: This paper demonstrates the thermal pyrolysis of olive residue, low density polyethylene (LDPE) and olive residue/LDPE mixture in an inert atmosphere of N2 using thermogravimetric analysis (TGA). Measurements were carried out in the temperature range 300K~973K at heating rates of 2K/min, 10K/min, 20K/min and 50K/min. Based on the results obtained, three temperature regimes were selected for studying the nonisothermal kinetics of olive residue/LDPE mixture. The first two were dominated by the olive residue pyrolysis, while the third was linked to the LDPE pyrolysis, which occurred at much higher temperatures. Discrepancies between the experimental and calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on copyrolysis. The maximum degradation temperatures of each component in the mixture were higher than those the individual components; thus an increase in thermal stability was expected. The kinetic parameters associated with thermal degradation were determined using Friedman isoconversional method.
Abstract: was carried out using thermogravimetric analysis with washing and salt adding samples. The original sample was washed with 5% acids (H2SO4, HCl) and distilled water, respectively. Inorganic compounds in pretreated samples were examined with ICP-AES. The catalysis effects of alkaline compounds on pyrolysis characteristics of original and pretreated biomass were analyzed with K2CO3 and dolomite (CaCO3·MgCO3) addition. The results show that acid wash can decrease the concentration of alkaline cations in biomass, enhance the mass loss rate of biomass pyrolysis, and shifts the pyrolysis to higher temperature. Alkaline compounds addition can promote biomass pyrolysis at lower temperature.
Abstract: The influence of indole on the hydrodesulfurization (HDS) of dibenzothiophene (DBT) and the influence of DBT on the hydrodenitrogenation (HDN) of indole were investigated over a presulfided NiMoS/γ-Al2O3 catalyst in a fixedbed highpressure microreactor. A significant negative effect of indole on the HDS of DBT was observed. The inhibitory effect of indole on the hydrogenation route (HYD) was stronger than on the direct desulfurization route (DDS). Indole and its HDN intermediate products suppressed HDS of DBT through the competitive adsorption on active sites of the catalyst. DBT and H2S produced insitu promoted the conversion of coordinatively unsaturated sites (CUS) to Brnsted acid sites on the catalyst surface, which in turn facilitated the cleavage of C(sp3)—N bond in indoline; the conversion of indole and the relative concentration of o-ethylanline (OEA) then increased. Although the presence of sulfur atoms is essential for the formation of active sites on the catalyst for HDN, a small amount of sulfur species is sufficient to maintain the HDN active sites; higher content of sulfides may bring on a negative influence on the HDN of indole.
Abstract: The protolytic cracking of Daqing vacuum gas oil (VGO) catalytic cracking process was studied by conducting multiple series of experiments from the low reaction conversion to high conversion over acid catalyst in a small fixed fluid bed (FFB) unit. A concept of the secondary protolytic cracking is proposed for VGO catalytic cracking process. The reactants of the secondary protolytic cracking are mainly paraffins in naphtha that are readsorbed on the acid catalyst and then cracked subsequently. The primary reason that causes the secondary protolytic cracking is the change of selective adsorption of the intermediate products on catalysts at the late reaction stage. The secondary protolytic cracking is not very sensitive to the reaction temperature. The portion of the secondary protolytic cracking in the whole protolytic cracking process is 60% for Daqing VGO at 500℃.
Abstract: To probe the possibility of producing microcrystalline wax with high melting point from Shenbei-Daqing vacuum residue, the residue was first deasphalted through a series of solvent deasphalting procedures with propane and butane to obtain deasphalted oil (DAO), and then the microcrystalline wax was prepared from DAO by solvent refining and dewaxing. The carbon number distribution, average molecular weight，composition and structure of microcrystalline wax were determined by GC, GPC, FT-IR and 1H-NMR. The melting points of microcrystalline wax samples meet the demands of 80# to 85# commercial products. The potential content of microcrystalline wax is about 10% in Shenbei-Daqing vacuum residue. The carbon number of the light microcrystalline wax ranges from 23 to 68. The number average molecular weight ranges from 1200 to 1600 and H/C atom ratio from 1.95 to 1.98. The microcrystalline wax is dominated by paraffins of long chains; of them about 70% are isoparaffins. There are a small amount of cycloalkanes and almost no aromatic hydrocarbons in the microcrystalline wax. The molecular structure of microcrystalline wax can be regarded as cycloalkanes with 1 or 2 rings and various long alkyl chains.
Abstract: SbSn intermetallic compound was synthesized by chemical method; its bulk phase structure, melting point and valence electron state on surface layer were determined by XRD, DSC and XPS. With SbSn powder supported on wire net as carrier, the viscosity variation of two types of crude oil emulsions was investigated through cycled process under electrifying. The SbSn product with Zn powder as reductive agent exhibited a particle size of between 500nm and 1000nm. With the extension of cycled processing time and the increase of electric field voltage, the viscosity of two types of emulsions declined obviously. After 20h processing at 10.35V, the viscosities of W(10)/O(90) and W(20)/O(80) decline from 9000mPa·s to 6000mPa·s and 8500mPa·s to 4500mPa·s, respectively. It was presumed that the viscosity reducing is due to the electrochemical reaction between negative polar organics in emulsion and SbSn surface on the condition of electric current induction.
Abstract: Thermal simulation experiments on n-heptane and six sulfates including Fe2(SO4)3, Al2(SO4)3, MgSO4, CaSO4, Na2SO4 and K2SO4 were carried out in autoclave in the presence of water to investigate the possibilities of thermochemical sulfate reduction (TSR). It was found that Fe2(SO4)3, Al2(SO4)3 and MgSO4 could intensely react with n-heptane at 400℃ to produce metal oxide and / or metal sulfide, hydrogen sulfide, coke and a series of organic sulfur compounds such as mercaptans, sulfoethers and thiophenes as the main products. Under the same reaction conditions, the extent of reactions of nheptane with CaSO4, Na2SO4 and K2SO4 is very limited. Based on the analysis of the gas-oil-solid 3-phase products of the reactions between n-heptane and six sulfates, the elementary steps and reaction mechanism of TSR were tentatively studied.
Abstract: The sulfur species and their distribution in the residua of Kazakhstan and Russia crude oils were investigated by using pyrolysisgas chromatography (PY-GC) with the pulsed flame photometric detector (PFPD). The major sulfur-containing products from the residua pyrolysis were H2S, thiophene species, benzothiophene (BT) species and dibenzothiophene (DBT) species; therefore, the pyrolysis of the model compounds thiophene, BT and DBT under 400℃~1000℃ for 5s～10s was carried out to determine the origin of sulfur species in the residua. Thiophene can easily be cracked into H2S, while BT and DBT are partially cracked into H2S. The reactivity of BT and DBT can be inhibited for pyrolysis in the blend of thiophene, BT and DBT; thus the sulfur pyrolysates can illustrate the origin of BT and DBT, while thiophene may be under estimated since it can easily be cracked. The residua of Kazakhstan and Russia crude oils were separated into 18 and 19 narrow cuts, respectively, by supercritical fluid extraction and fractionation. The sulfur species distribution for sulfides, thiophenes, BTs and DBTs in these narrow cuts and non extractable end cuts were obtained through the pyrolysis at 1000℃ for 10s. As the cuts become heavier, the sulfur content in each cut increases; the relative fraction of thiophene sulfur in total sulfur content also increases, while the relative sulfide sulfur fraction decreases. Russia vacuum residue and its cuts show higher total thiophene contents than Kazakhstan vacuum residue and its corresponding cuts.
Abstract: The catalyst for slurrybed hydrotreating of distillate oil was prepared; the preparation parameters like the loading of active components and phosphorus additive on the hydrotreating performance were investigated. The optimum catalyst (SP25) was obtained through impregnation of γ-Al2O3 particles with an aqueous solution of ammonium tetrathiomolybdate (ATTM) and certain complexing agent, drying at 120℃ for 12h, then impregnation with an aqueous solution nickel nitrate and ammonium dihydrogen phosphate, drying at 120℃ for 12h, at last calcined at 500℃ in N2 atmosphere for 3h. The as-prepared catalyst SP25 exhibited a specific surface area of 212.3m2/g, pore diameter of 11.3nm, pore volume of 0.60mL/g, particle size of 17.3μm, skeleton density of 2.79g/cm3; the active components in the asprepared catalyst were in sulfided form and presulfurization was not necessary before using. XRD and H2TPR suggested that the addition of complexing agent during impregnation could enhance the dispersion of MoS2 on γAl2O3. Under the conditions of 350℃, 6MPa, wcatal/woil = 6%, reaction time 2h, the efficiencies of hydrodesulfurization and hydrodenitrogenation for FCC diesel oil reached 85.1% and 82.0%, respectively.
Abstract: The catalytic reactions of C4 hydrocarbons on a fluid catalytic cracking (FCC) catalyst were studied in a confined fluidized bed reactor. The effect of reaction temperature and space velocity on product yields and distribution was investigated. The results show that the FCC catalyst has the good performance of aromatization and cracking of C4 hydrocarbons and can be used to produce propylene and aromatics under the suitable reaction conditions. It is mainly the butylene in the C4 hydrocarbons that undergoes catalytic reactions over the FCC catalyst and butane is hard to convert. Low reaction temperature favors the production of aromatics, while high reaction temperature favors the production of propylene. Low space velocity is beneficial to promote the conversion of butylene and the production of both aromatics and propylene. According to the bimolecular mechanism and reaction results, the reaction network for the catalytic reactions of C4 hydrocarbons on the FCC catalyst is proposed. The analysis on the this reaction mechanism indicates that the main reason of resulting in the lower yields of ethylene and propylene could be the poor secondary cracking performances of C5 and C6 olefins formed in the catalytic conversion of C4 hydrocarbons on the FCC catalyst.
Abstract: The La2O3-ZrO2-Al2O3 composite support was prepared by coprecipitation method with the mixed aqueous solution of La(NO3)3, Al(NO3)3, and ZrOCl2 dropping into the precipitant of (NH4)2CO3 aqueous solution. The Cu/La2O3-ZrO2-Al2O3 catalyst was prepared by the impregnation of La2O3-ZrO2-Al2O3 with active component Cu2+ aqueous solution. The effects of the catalyst on the selective catalytic reduction of NO with propylene in excess oxygen were investigated. The relationships among the preparation method, structure, and properties of the Cu/La2O3-ZrO2-Al2O3 catalyst were also explored by means of Scanning electron microscope(SEM), X-ray diffraction（XRD）, Surface area measurements (BET), Pyridine absorption infrared spectrum (Py-IR), Thermalgravimetry(TG), and Temperatureprogrammed reduction (TPR). The results indicate that the support γ-Al2O3 prepared by Al(NO3)3 dropping into (NH4)2CO3 can remarkably enlarge the surface area; the addition of La2O3 contributes mainly to the enhancement of the thermal stability; the introduction of ZrO2 can increase the amount of Lewis and Brφnsterd acid. Consequently, the catalyst Cu/La2O3-ZrO2-Al2O3 has excellent activity for the selective reduction of NO with propylene in excess oxygen. The NO conversion is up to 88.9% at 300℃ and 81.9% even at the presence of 10% volume fraction of water vapor.
Abstract: The carburizing reaction of molybdenum trioxide was investigated in CH4/H2 mixture using insitu TG-DTA. The effects of ramping rate and carburization temperature on the carburizing reaction of molybdenum trioxide were also studied. The results indicate that molybdenum carbide can be prepared by temperatureprogrammed reaction(TPR) to carburize molybdenum trioxide through the pathway of MoO3→MoO2 →MoOxCy→Mo2C under CH4/H2 atmosphere at ramping rate of 1℃/min with the optimal carburization temperature of 675℃. When the ramping rate is above 2℃/min，the carburizing reaction process of molybdenum trioxide changes to MoO3→MoO2→Mo＋MoOxCy→Mo2C. In the mean time, the amount of Mo element generated in the second weight loss stage increases with the increase of the ramping rate. The beginning and the finishing temperature of carburizing reaction also increase with in the increase of the ramping rate. Despite the fact that the carburizing reaction pathway of MoO3 in CH4/H2 mixture is similar in a range of carburizing temperatures, high reaction temperature could lead to the coking reaction of the hydrocarbon and deposit of free carbon on the catalyst surface, which could induce the BET surface area decrease and hence reduce the catalytic activity of the Mo2C.
Abstract: Na-P1 zeolite was synthesized by hydrothermal method from coal fly ash and used to remove fluorine from drinking water. The effects of adsorption time, zeolite usage and fluorinion concentration in water on the removal efficiency were investigated. The results suggested that the fluorine adsorption capacity of Na-P1 zeolite can be enhanced significantly through the modification with 1.0% NaOH solution for 12h and 2.0% KAl(SO4)2 solution for 36h in turn. The fluorine removal ability increases with the adsorption time and the amount of zeolites used. The mechanism of the adsorption was also discussed. The adsorption isotherm could be descried by the Langmuir isotherm equation.
Abstract: Mass loss process of fly ash from solid waste incineration was investigated by high temperature TG apparatus. The experiment was performed at the range of 40℃~1400℃ under heating rate of 10℃ /min and N2 atmosphere. Two main mass loss peaks were found at 800℃~1000℃ and 1000℃~1200℃, respectively. Weight loss ingredients and air pollutant were investigated by benchscale experiment. The results shows that emissions of heavy metals and air pollutant in these two temperature spans exceed National Standard, and ash melting must be operated carefully.
Abstract: Considering the reaction of SO2 and surface CuO，a mathematical model based on the grain model was developed to simulate the SO2 removal process over a NH3-regenerated CuO/Al2O3 pellet. SO2 removal from flue gas over CuO/Al2O3 pallets of various sizes was carried out in a thermogravimetric analyzer to study the effects of reaction temperature, particle diameter and porosity, and to validate the single particle model developed. The reaction of CuO with SO2 and O2 yields CuSO4 that is larger in molecular size than CuO and results in a decrease in particle porosity and gas diffusivity. The effective SO2 diffusivity can be correlated with CuO conversion by De=α(1-x)b, which allows the model to fit the experimental data better. Mathematical analysis using this particle model indicates that the pore diffusion is important for the SO2 removal over CuO/Al2O3 pallets and the activation energy of pore diffusivity increases with the reaction going on.
Abstract: A series of oxides (WO3, MoO3, CrO3, MnOx, FeOx and CoOx) supported on homogeneously precipitated CeO2-ZrO2 prepared by incipient wetness impregnation was used as catalyst for the selective catalytic reduction (SCR) of NO in diesel exhaust with NH3. The catalyst was aged in air at 800℃ for 1h and tested in a simulated diesel exhaust containing 0.055% NO, 0.055% NH3, 6% O2, 10% H2O and 10 % CO2, at a space velocity of 90000h-1. The catalyst WO3-CeO2-ZrO2 exhibited high thermal durability. The effects of WO3 loading and Ce/Zr ratio in WO3-CeO2-ZrO2 were examined; 10% WO3 and equimolar composition of Ce-Zr gave it a superior performance for NH3-SCR of NO. The fresh and aged catalyst samples showed a NO conversion above 90% at temperatures 250℃~450℃ and 350℃~500℃, respectively. The catalysts also exhibited the excellent performance for circle and longterm aging.
Abstract: The copper-manganese mixed oxides prepared by coprecipitation were tested for water gas shift reaction on a micro-reaction system with on-line GC analysis and characterized by XRD，TEM，BET and TPR. The adding rate of precipitator has significant effect on the texture and activity. The copper-manganese mixed oxide with adding time of precipitator less than 33min presents higher activity, especially the higher thermo stability. The coppermanganese mixed oxide prepared at adding time of precipitator less than 160min are mainly consisted of Cu1.5Mn1.5O4. With the increasing of adding time of precipitator, especially for longer than 160min Mn2O3 appears. After catalytic reaction MnO, Cu and Cu2O are the crystalline structure of the samples. With the increase of Mn2O3 the activity, especially the thermo stability activities decrease. Therefore, it can be concluded that the adding rate of precipitator is most curial factor for the preparation of high performance coppermanganese mixed oxides for the water gas shift reaction.
Abstract: Zinc-substituted aluminophosphate molecular sieves (ZnAPO-5, AFI topology) containing different zinc contents were synthesized by static hydrothermal method, using triethylamine as an organic template agent. The as-synthesized ZnAPO-5 molecular sieves were characterized by XRD, SEM, N2-adsorption, MAS-NMR and ICP-AES techniques. Experimental data indicate that Zn as a heteroatom was successfully incorporated into the framework of AlPO4-5. The resultant ZnAPO-5 molecular sieves with regular hexagonal prism morphology are of high crystallinity and purity. The n-hexane cracking over ZnAPO-5 was examined under different reaction conditions. It is found that ZnAPO-5 molecular sieves exhibit a moderate activity for the n-hexane cracking conversion in the temperature range of 723K~823K. The cracking results obtained show that the conversion level of n-hexane increased with increasing reaction temperature and contact time, and that the first order was determined in the nhexane concentration. Relations between rates and reaction temperature can be expressed in terms of Arrhenius formula in the whole temperature range. Based on the kinetic data and product distributions, monomolecular protolytic mechanism was concluded to prevail under the reaction conditions applied.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
