Abstract: The CO2 gasification of Fuijian anthracite using black liquor (BL) as a catalyst was performed in a thermogravimetry analyzer (TGA) under the temperature ranging from 750℃ to 950℃ at ambient pressure to evaluate the catalytic effect of 3%, 5%, 8%, 10%NaBLLoading on carbon conversion. Better catalytic activity was found with 8%NaBLLoading than those of other concentrations. Under the reaction control conditions the relationships of coal conversion vs reaction time of three kinds of Fuijian highmetamorphous anthracites were measured within temperature range from 750℃ to 950℃. Both homogeneous model (HM) and shrinkingcore model (SCM), were applied to correlate the relations between conversion and time and to determine the reaction rate constants (k) under different temperatures, then the reaction activation energy (Ea) and the preexponential factor (A) of the three anthracites were predicted by using Arrhenius equation k＝A·exp(－Ea/RT). The Ea ranged from 76.18kJ/mol to 104.22kJ/mol at 8% NaBL Loading condition was detected, which is less than that from 150.93kJ/mol to 185.44kJ/mol at noncatalyst case, clearly demonstrating that the BL could be the source of inexpensive and effective catalyst for coal gasification.
Abstract: The effect of char on the melting characteristics of coal ash was studied in the argon atmosphere using an ash fusion determinator connected with a camera and a computer. The results show that the coal char in ash has remarkable influence on the ash melting points as well as the ash melting behavior. The effects are related to the coal rank and the char content addition. For the coal ashes investigated, the deforming temperatures (DT), the softening temperatures (ST), and the flowing temperatures (FT) of all samples with the addition of coal char are higher than those of corresponding initial ashes. The ash melting points increase with the coal char addition amount. When the content of coal char is 20% and the temperature reaches or exceeds the corresponding original ash melting point, an infusible skeleton can be formed because of the sticking interaction between char and ash. When the skeleton is formed, the softening temperature and flowing temperature of the sample are difficult or impossible to occur.
Abstract: The swelling behavior in different solvents of 4 bituminous coals with different ranks and their residues from extraction by CS2/NMP mixed solvent (1∶1 in volume) were measured. The change in swelling property of the four coals thermally treated at different temperature was observed. The results show that the swelling ratio decreases with increasing rank of coal. For lower rank bituminous coals the swelling ratios in polar solvent are higher than those in nonpolar solvent, and this difference decreases with increasing rank. The crosslinking densities of the four residues decrease, and the swelling ratios increase compared with those of raw coals. The swelling ratios of the four thermally treated coals under 150℃ in CS2 increase, suggesting the decrease in crosslinking density of them. When the thermal treatment temperature increases to 240℃, the swelling rations of the other three coals in NMP and CS2 increase again except gas coal, demonstrating the further decrease in crosslinking density. This result is coincident with the extraction yield change in the mixed solvent of the thermally treated coal. For example, the extraction yield of lean coal treated at 240℃ increases from 6.9% to 17.3%. FT-IR results show the removal of oxygen group of the thermally treated coals. This may explain the increase in swelling ratio and extraction yield in the mixed solvent of coal after thermal treatment. The crosslinking density of the thermally treated coal decreases because of the break of hydrogen bonds due to removal of C=O and OH oxygen groups during the thermal treatment, resulting in the increases of swelling ratio and extraction yield in the mixed solvent of thermally treated coal compared with those of raw coal.
Abstract: Twenty four Chinese coals with various ranks were used and systemically analysisd. The correlationships of the CWS properties including slurryability, rheological behaviour, and static stability with the coal properties were investigated by the plurality linear regression analysis and multivariate progressive regression analysis, respectively. The results show that the carbon content, the moisture content by air drying ,the grindability index, and the surface area by Mercury Porosimeter are the main factors influencing the slurryability of CWS. The content of ash, the content of soluble mineral matters in CWS, the pore volume and the Zetapotential properties of coal surface mainly affect the rheological behaviour of CWS. The content of inertinite in petrographic macerals and the content of SiO2 in coal ash are the major factors influencing the static stability of CWS.
Abstract: An experimental study was conducted on the porous structure of the char particles of JX anthracite by using nitrogen absorption method. The coal chars were produced under high temperatures ranging from 1500K to 1800K in a drop tube furnace. The distributions of specific surface area and pore volume with pore diameter were derived by using BET and BJH methods. It is found that the pores in microsize and mesosize are major contributors for the overall specific surface area and pore volume. Furthermore, with the increasing of pyrolysis temperature, the specific area and pore volume vary in the shape of mountain and the temperature of peake is around 1600K. The SEM observation shows that the surface of char particles becomes smoother and denser when the pyrolysis temperature is higher than 1600K. It is suggested that the melting of internal ash during high temperature pyrolysis is the main cause for such a phenomenon, and thus the turning point is related to the melting point of the char.
Abstract: Dongdu weathered coal was oxidized with nitric acid. The structures and properties of the products of nitric humic acid (NHA) were investigated by element analysis and Fourier Transform Infrared Spectra (FT-IR). Effects of catalyst on NHA yield, elemental composition and functional group were discussed. The results show that NHA yields increase apparently with catalyst of H2SO4, H2O2, carbon transition metals supported on carbon nanotubes (CNTs) and solid acid. The contents of carbon, hydrogen and H/C atomic ratio of NHA produced decrease while nitrogen contents and E4/E6 value increase. Nitrogen contents increase apparently in the presence of solid acid or H2SO4. Molecules of NHA produced with catalyst of ferric oxide supported on nickel plating CNTs, nickel supported on CNTs or H2SO4 are smaller. The contents of active functional groups increase significantly with catalyst and the influence is dependent on the kind of catalyst.
Abstract: Experiments to examine the combustion characteristics of residues from sawdust liquefaction under different operation conditions (solvent, atmosphere, temperature and catalyst) were performed in a thermogravimetric analyzer (TGA92). The effect of liquefaction conditions on the combustion property of the residues was examined through comparing their characteristic parameters such as ignition temperature (ti), peak temperature of maximum weight loss rate (tp) and burnout temperature (tb). Based on the TG/DTG profiles, a residue combustion kinetics model was proposed and the kinetics parameters such as activation energy (E) and frequency factor (A) were obtained by Coats-Redfern method. The results show that liquefaction solvent could affect the combustion characteristics of residue obviously. The residue from biomass liquefaction with tetralin as solvent has the best combustion reactivity than both with toluene as solvent and without solvent, while the higher heating value of residue has the opposite trend. The residues from different liquefaction atmospheres almost have the same combustion characteristics. Other liquefaction conditions such as temperature and catalyst also could affect the combustion characteristics of residues. The kinetics of residue combustion could be described by a two-stage first order kinetic model.
Abstract: In order to quickly and economically obtain the information of molecular changes occurring in heavy oils during thermal processing, simulated mixtures of heavy oils and their pyrolyzed products were prepared from four model compounds, i.e., naphthalene, tetralin, decalin, and nheptane. FT-IR absorption characteristics and average molecular parameters of the mixtures were correlated; the molecular parameters included the number ratio of methylene to methyl (NCH2/NCH3), hydrogen aromaticity (faH), atomic ratio of hydrogen to carbon of the aromatic sheet (NHar/NCar), etc. Considering heavy coker gas oil (HCGO) as a heavy oil feedstock, HCGO was thermally processed in an autoclave and its gas oil fraction (GOF) was separated into group fractions and analyzed by FTIR. The results show that the simulated mixtures show good linearity between faH and the absorption area ratio of the bands at 2750cm－1～3100cm－1 to 3000cm－1～3100cm－1 (S3000~3100/S2750~3100), and so doesNCH2/NCH3 and absorbance ratio of the bands at 2920cm－1～2960cm－1 (A2920/A2960). These correlations could be useful tools for illustrating molecular changes occurring in heavy oil during thermal processing. As the processing proceeds, the NCH2/N１CH3 of the saturate molecules increases first and then declines, in sharp contrast to that of the aromatic molecules, which shows a consistent decline. As far as faH or NHar/NCar is concerned, however, the aromatic molecules show a rising trend. The chemistry behind these phenomena is also discussed in some detail.
Abstract: Nanonickel catalyst was prepared in methylcyclohexanewater noctanolAEO9 microemulsion system, and used in the viscosity reduction process of Liaohe extraheavy oil by aquathermolysis. It is observed that the nanonickel could catalyze the aquathermolysis reaction of extraheavy oil at 280℃. The experimental results demonstrate that compared with the original crude oil sample, the mean molecular weight of the upgraded sample decreases, the content of sulfur changes from 0.45% to 0.23%, the content of resin and asphaltene reduces 15.83% and 15.33%, respectively. Based on the GC-MS analysis results, a reaction pathway is proposed that involves hydrogen transfer from methylcyclohexane to the extraheavy crude oil resulting in the formation of toluene. During the cooling process after upgrading reaction, the W/O emulsion is formed because of the presence of the surfactant AEO9. As a result, with respect to the original crude oil, the viscosity of upgraded sample is changed from 139800mPa·s to 2400mPa·s at 50℃, an approximately 98.90% reduction by the synergetic effects of upgrading, emulsification and diluting.
Abstract: FCC light gasoline containing great lot olefins is a kind of good catalytic cracking feedstock for propylene production. A series of experiments about catalytic cracking of light gasoline and 2M1C5＝were carried out with the ZSM-5 catalyst under different conditions on the riser experimental unit and the subminiature reactorchromatograph united apparatus. Results show that the contents of C5＝ and C6＝ in FCC gasoline can be enhanced via using the ZSM-5 catalyst in catalytic cracking. Light gasoline is more suitable for producing propylene than heavy gasoline or full fraction gasoline. High propylene yield can be obtained from light gasoline even when reaction temperature is low and the contact time is only several milliseconds. The effects of temperature and flow velocity of N2 on propylene yields of cracking light gasoline and 2M1C5＝are nearly the same, namely propylene yield increases when temperature increases or flow velocity of N2 decreases. The ratio of propylene to butenes can rise via increasing temperature and prolonging contact time. The coking rate of the ZSM-5 catalyst is rapid at beginning and afterwards slow gradually. There is a greater influence of the coking of ZSM-5 catalyst on propylene yield than on butenes yield. It is beneficial to increase propylene yield when there are more strong sites on ZSM-5 zeolite.
Abstract: The oxidative desulfurization (ODS) of diesel oil in the presence of copper ion and hydrogen peroxide was investigated with ultrasonic irradiation as an extra energy. The effects of operation parameters such as the aqueous phase pH and ultrasonic power on the desulfurization efficiency were examined and the ODS mechanism under ultrasonic irradiation was suggested. The results showed that the sulfur removal rate increases at first, and then decreases with an increase in the aqueous phase pH; the highest sulfur removal rate is obtained at about pH = 2.00. ODS is in conformity with apparentfirst order kinetics for any of the four cases: with hydrogen peroxideacetic acid (without ultrasound), Fentontype reagent (without ultrasound), combination of ultrasound and hydrogen peroxide, and combination of ultrasound and Fentontype reagent. Moreover, the sulfur removal rate increases with the ultrasonic power, because the production of cavitation bubbles in the liquid and the collapse of the bubbles are enhanced by the ultrasonic power.
Abstract: Adsorption desulfurization by activated carbon obtained from DuShanzi petroleum coke was investigated. The activated carbon was prepared through the improved physical activation and the surface area reached 500m2/g～900m2/g; its porous structure and distribution were modified by acid oxidation. With the surface acid oxidation, the amounts of oxygen function groups on the activated carbon surface increases for almost 5 times more than those on the original activated carbon. The optimum nitric acid oxidation conditions are 120oC and 40min. The optimum process conditions of desulfurization are 25oC, 1.0MPa and 6 hours by static status adsorption. Under these conditions, the sulfur content of model compound decreases from 137.9×10－6to 3.1×10－6. Activated carbon with the average pore diameter from 0.8nm to 2.1nm was effective to reduce the sulfur content in the model compound, it suggest that such a microporous structure could benefit the desulfurization.
Abstract: The FeMnCu/ZnO catalysts for higher alcohols synthesis were prepared by coprecipitation and sequential precipitation methods. The texture and structure properties of FeMnCu/ZnO catalysts were characterized by ICP, BET, XRD, and TPR. The catalytic activity for C1~5 alcohol synthesis was determined in a fixed bed flow reactor system. The results showed that the catalytic performance of the catalysts was influenced by the precipitation methods remarkably. The alcohol yield and alcohol selectivity of sequential precipitation catalysts were obviously higher than that prepared by coprecipitation method. The alcohol selectivity of 33.5% with C2+ alcohol selectivity of 31.72% was obtained over “Fe atop Cu” catalyst under the reaction condition of T=503K，p=8.0MPa，GHSV=8000h－1，H2/CO＝2(volume ratio). It was found that sequential precipitation exhibited larger pore size, which could be favorable for long chain molecules to diffusion. The catalysts prepared by sequential precipitation method showed better dispersion of CuO and ZnO. Therefore, the performance for higher alcohols synthesis over catalysts prepared by sequential precipitation can be promoted. The copper ions in sequential precipitation were found to be reducible as compared with coprecipitation catalyst due to their initial temperature of reduction. Combined with the performance of the CO hydrogenation, better performance for higher alcohols over catalysts prepared by sequential precipitation can be ascribed to a mount of reducible Cu species.
Abstract: The synthesis of isobutyraldehyde from methanol and ethanol was investigated over vanadium catalysts at 375℃ and under normal atmospheric pressure. The influence of V2O5 content and preparation conditions of catalysts on catalytic performances was studied. The results showed that 75% V2O5 content, 480℃ calcination temperature and 2h calcination time were the optimum conditions, and the ethanol conversion and isobutyraldehyde selectivity reached to 98.03% and 47.52% respectively. The fresh, reacted and regenerated catalysts were investigated by XRD and the reacted catalyst was also tested by DTATG to establish change of vanadium oxide. The results showed that V2O5 was reduced to V2O3 during reaction and deactivated catalyst could be regenerated.
Abstract: MnH-4SiW12O40/SiO2 heteropolyacid catalysts were prepared by impregnation method from different Mn salt precursors, such as MnSO4, Mn(NO3)2, MnCl2 and Mn(CH3COO)2. The catalytic oxidation reaction of dimethyl ether (DME) to dimethoxymethane (DMM) was carried out in a continuous flow type fixedbed reactor with a ratio of DME/O2=1∶1(md ratio). It is found that the sequence of catalytic activity for DMM synthesis is Mn-Cl2H4SiW12O40/SiO2 > Mn-(NO3)2H4SiW12O40/SiO2 > MnSO4H4SiW12O40/SiO2 > Mn(AC)2H4SiW12O40/SiO2. The effects of reaction temperature (573K～633K) on the catalysts were also investigated. With the increase of reaction temperature, the DME oxidation reaction is more exquisite over MnSO4H4SiW12O40/SiO2 catalyst. 42.4% of DME conversion and 0.9% of DMM selectivity have also been obtained at 613K. However, MnCl2 modified H4SiW12O40/SiO2 catalyst obtains higher DMM selectivity (37.5%, at 593K) than other three catalysts at mild reaction conditions. H2TPR profiles show that MnSO4 modification demonstrates stronger oxidative performance at high temperature than other catalysts, while MnCl2H4SiW12O40/SiO2 catalyst exhibits better oxidative performance at low temperature. XRD patterns of the catalysts show that the diffraction peaks are strong and MnO2 diffraction peak is also found over the MnCl2 modified catalyst.
Abstract: The effect of pressure on coke and its precursor's formation was studied during catalytic cracking of toluene over USY catalyst. The coke and its precursors were characterized by TGA, FTIR, solidstate 13C NMR，elemental analysis, GCMS, and temperatureprogrammed oxidation (TPO) analysis. The results indicate that coke deposited on the catalyst is mainly composed of polyaromatic hydrocarbons (PAHs). It reveals that the total amount of coke decreases, whereas the number of the rings of PAHs and yields of PAHs in the liquid phase increase with increasing cracking pressure. It is concluded that supercritical fluid plays an important role in extracting coke precursors during catalytic cracking.Finally, the mechanism of coke formation was proposed.
Abstract: Nanocrystalline ZnFe2O4 with crystallite size of 15nm～32nm was directly synthesized by stearate precursor. The overall process involves three steps: formation of homogeneous sol, formation of dried gel, and calcination of the dried gel. TG-DTA, XRD and BET techniques were used to analyze and characterize the dried gel and the assynthesized sorbent, respectively. The results show that the zinc ferrite prepared by stearate precursor could proceed at relatively lower temperature. The calcination temperatures have great impact on the desulfurization performance of zinc ferrite. When the temperature increases, the specific surface area decreases and the average crystallite size increases, which results in deterioration of desulfurization performance of the sorbent. The prepared sorbent shows a high reactivity and high sulfur capacity when operated at moderate temperature range. It also has good reproducibility and can be regenerated even at 450℃. These indicate that the stearate precursor technique would be a potential approach for the synthesis of desulfurization sorbent.
Abstract: The airborne particle samples were collected onto the glass filter with a five stage cascade impacter sampler. The samples gathered from rural and urban area of Beijing in four seasons in 2003 were analyzed. The aromatic fractions were analyzed by gas chromatography-mass spectrometry. The characteristic of the contents of total priority polycyclic aromatic hydrocarbons (PAHs) of different seasons shows that winter is the most,autumn is the second, spring is the third and summer. Particle size distribution of PAHs with different rings were compared. The result shows that the ratios of 2 or 3rings PAHs in the grain particles are bigger than those of high rings PAHs.
Abstract: β Zeolite supported molybdenum carbide catalyst has been prepared by temperature programmed reduction with n-pentane as a source of carburization, and characterized by XRD. The influences of reaction temperature, pressure, space velocity and the ratio of hydrogen to hydrocarbon on the catalytic performance for hydroisomerization over βMo2C/β zelite have been investigated in a fixedbed downflow reactor using n-heptane as a model reactant. The optimum conditions for the isomerization of n-heptane were 270℃～275℃, 1.0MPa～1.5MPa, LHSV 1.0h－1and the hydrogen to hydrocarbon ratio (Volume Ratio) 200∶1. The results of the reaction showed that the selectivity and yield of isomers reached to 71% and 58%, respectively, with the n-heptane conversion of 82% in the optimum conditions.
Abstract: Fe, Mn substituted Lahexaaluminate were synthesized by reverse microemulsion in system of water / Triton X-100 /n-hexanol / cyclohexane. The effects of substituted elements on phase, specific surface area were investigated by means of XRD and BET. The results indicated that the synthesis method could make the hexaaluminate crystal form at lower temperature, 1100℃. Among 了LaMxAl12－xO19－α catalysts, the catalyst with 1 Mn iron (x=1) was the best. The introduction of Mn could improve the catalytic activity at low temperature and make methane lightoff temperature shift to lower value. Fe substituted Lahexaaluminate could make methane completely convert at lower temperature. Fe and Mn substituted LaMnFeAl10O19α had the highest activity at both low temperature and high temperature. Stability experiment was carried out for 100h, the conversion kept99.7％, and no deactivation was observed.
Abstract: Pyrolysis of three high rank coals, Changcun, Rujigou and Jincheng, were investigated by TG, and the evolved hydrogen was on-line analyzed by mass spectroscopy. The results show that Rujigou and Jincheng coals have higher initial pyrolysis temperature, higher temperature of maximum weight loss rate and lower maximum weight loss rate. This indicates that the macromolecular structure tends to be stable with the increase of coal rank. Analysis of the evolution characteristics of hydrogen indicates that the initial temperatures (t0) of hydrogen evolution increases with the increase of carbon content. The maximum rate temperature (tmax) is the highest for Changcun coal. This maybe relates to the low aromaticity of Changcun coal. The condensation between the aromatic hydrocarbons will occur up to higher temperature. The evolution intensity of hydrogen from Changcun coal is obviously higher than that for Rujigou and Jincheng coal.
Abstract: The pyrolysis of Zhalaiteqi oil sand was undertaken with a fixedbed reactor under nitrogen atmosphere. Effects of pyrolysis temperature, time and flow rate of carrier gas on the oil and water yield were analyzed in detail. Optimum pyrolysis condition of the oil sand was determined as well. The oil yield from NO.2 and NO.6 oil sand is 12.55% and 7.18%, respectively. It is 22.92% and 43.03%, respectively, higher than the carbonization result with aluminum retort. The results indicate that pyrolysis is a good way for Zhalaiteqi oil sand to produce oil.
Abstract: A experimental study of characteristics of NO reduction by a simulating production gas of biomass gasification was performed in a ceramic flow reactor heated by an electric furnace. The gas was composed of CO, CO2, CH4, H2 and N2, and the temperature used in the experiments ranged from 1000℃ to 1400℃. The influence of the inlet concentration of oxygen (0%～5%), the local equivalence ratio, φ(0.5～2.28), and the reactor temperatures was studied to analyse the characteristics of biomass gasificationreburning. The results indicate that more consumption of reducting agent is needed to increase the NO reduction efficiency in pyrolysis condition. The suitable values of the local equivalence ratio, φ, could make the NO reduction efficiency in oxidation condition higher than that in pyrolysis condition. The local equivalence ratio is an important parameter for NO reduction, and higher NO reduction efficiency can be obtained when 〖φ varies between 0.8 and 1.1. The reduction of NO is favored at high temperatures.
Abstract: A new adsorptive resin, N,Ndi(2chloroethyl)sulfonamide resin, was synthesized through the modification of sulfuric acid resin with di(2chloroethyl)amine. Its capacity and selectivity on the adsorption of six typical organic sulfides was investigated in the hydrocarbon samples. The results indicated that the resin exhibits different adsorption abilities for various sulfides; the adsorption activity decrease in the order of primary mercaptan, secondary thiophene mercaptan, and then sulfur ethers benzothiophene.
Abstract: Molecular sieves of SAPO-41 with different silicon contents were synthesized and characterized by XRD, N2 adsorption, XRF, pyridineIR and 29SiMAS-NMR. The isomerization properties of the SAPO-41 were investigated by using m-xylene as a feedstock. The SAPO-41 obtained from the synthesis gel with SiO2/Al2O3=0.3 showed the highest activity to the isomerization of m-xylene and the largest number of Brnsted acid sites was also observed with PyIR over this sample. The state of Si in the framework of SAPO-41 plays a predominant role on the Brnsted acidity. The relationship between the activity and the acidity obtained in this study can be explained in terms of the distribution of stronger Brnsted acid sites.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
