Abstract: Effects of liquefaction conditions, including temperature, time, initial hydrogen pressure, and catalyst dosage on direct liquefaction were investigated by batch hydro-liquefaction of Shenhua coal catalyzed by SO42-/ZrO2 solid acid. The mechanism and catalysis of Shenhua coal liquefaction catalyzed by SO42-/ZrO2 solid acid were also discussed by distribution and IR analysis of the products. The results indicate that increase in temperature is favorable for catalytic hydrocracking of coal, an increase in liquefaction conversion, and yields of oil plus gas. Raising the initial hydrogen pressure facilitates coal conversion into asphaltene and preasphaltene, but depresses the formation of oil and gas. The increase of liquefaction time is beneficial to the hydrocracking of preasphaltene with an increase in yields of oil plus gas. SO42-/ZrO2 solid acid mainly catalyzes the hydrocracking of coal macromolecular structure so that the conversion and yields of oil plus gas increase with increasing catalyst dosage. In addition, the conversion of the oxygen-containing structures such as hydroxyl needs high liquefaction temperature and initial hydrogen pressure.
Abstract: A new method to recycle waste liquor from cellulose ethanol fuel was suggested. It was mixed with coal to prepare slurry which could be utilized as fuel. Rotating viscometer was used to determine the rheology of waste liquor coal slurry of cellulose ethanol fuel (WLCS-CEF). The effects of slurry concentration, dosage of waste liquor and additive on rheology of WLCS-CEF were studied. The apparent viscosity increases with the increasing of solid concentration and dosage of waste liquor. Additive could improve the rheology greatly. Constituents with large molecular weight in the waste liquor (lignin, cellulose and semicellulose) are not hydrolyzed completely, which is able to stabilize the WLCS-CEF. Meanwhile, the stability of WLCS-CEF is better than coal-water slurry at the same concentration. The stability of WLCS-CEF increases as slurry concentration increased, and suitable additive can also improve its stability. When additive A was used, and the concentration of WLCS-CEF is 62% with the waste liquor dosage of 2.5%. It is much more suitable for gasification.
Abstract: Some influencing factors on hydrogen production from steam gasification of lignin with Al2O3·Na2O·xH2O/NaOH/Al(OH)3 catalyst in a fixed bed reactor were examined. The results show that the formation rates of hydrogen increase with increasing ratio of Na2O/C and ratio of vapor to lignin as a whole. Higher flow rate of vapor is conducive to inhibit the generation of CO and CO2 at lower temperature. H2O(g) produced by the hydrates contained in the catalyst can bring on more Na+ and OH- ions to be formed by dissociation of NaOH within the catalyst. This leads to more remarkable reduction of the C—H bond energies of lignin. The conversion degree of hydrogen of lignin at 473K~973K reaches 134.94%, which shows that the present catalyst has good catalytic activity on hydrogen production from steam gasification of lignin at low temperature.
Abstract: Novel five basic binuclear functional ionic liquids with an imidazolium structure were synthesized via a two step method and used as the catalyst in the preparation of biodiesel through transesterification from cottonseed oil. The ionic liquids exhibit good catalytic performances in the transesterification; among them, bis-(3-methyl-1-imidazolium-)-ethlyene dihydroxide performs best. Their catalytic activity is related to the lengths of the carbon chain in the cations. The influences of the catalyst dosage, reaction time and temperature, and the molar ratio of methanol to cottonseed oil on the transesterificaion were investigated. The fraction and selectivity of fatty acid methyl ester in the biodiesel product reach 98.5% and 99.9%, respectively, at 55℃ for 4h with a bis-(3-methyl-1-imidazolium-)-ethlyene dihydroxide catalyst dosage of 0.4% and methanol to cottonseed oil molar ratio of 12. The fraction of fatty acid methyl ester can be maintained at 96.2% with only little monoglycerides and diglycerides in the product after the catalyst is repeatedly used for 7 times, which implies that these bication ionic liquids with an imidazolium structure are suitable catalysts for the synthesis of biodiesel through transesterification.
Abstract: A kind of Fe(II)-Zn double-metal cyanide (DMC) complexes solid catalyst was prepared through coreaction of potassium ferrocyanide, zinc chloride, and complexing agent of tert-BuOH. The catalyst has highly catalytic activity on the simultaneous transesterification of triglycerides and esterification of free fatty acids (FFA) reactions. The effect of various factors on the reaction was studied, including different cocomplexing agents, DMC catalyst amount, reaction temperature, methanol/oil molar ratio, reaction time, and water and fatty acid content in raw materials. High catalytic activity was observed for DMC under relatively higher content of water or FFA. Under the optimum condition the methyl ester yield can reach 98%. 93.45% of the catalyst can be recovered after 6 cycles.
Abstract: Transesterification of Swida wilsoniana oil with methanol to biodiesel was conducted by using the immobilized lipase Lipozyme TL IM as the catalyst in MgCl2-saturated solution. The effects of alcohol/oil molar ratio, immobilized lipase loading, agitation speed, and reaction time on the transesterification were investigated. The yield of biodiesel reaches a maximum value of 86.5% after reaction for 8h under the optimal conditions: methanol/oil molar ratio of 3, 20% of Lipozyme TL IM based on Swida wilsoniana oil, and agitation speed of 150r/min. Compared with the traditional transesterification methods like using 3-step methanolysis or with tertiary butanol as solvent, the problem of immobilized lipase inactivation is solved effectively by using the MgCl2-saturated solution. Moreover, the current process has potential for biodiesel production owing to its improvement in lipase stability, reaction efficiency, and production costs.
Abstract: A bifunctional catalyst JC207/HZSM-5 was used for dimethyl ether(DME)synthesis from a biomass- syngas, which was produced by pine sawdust steam gasification combined with two sections of catalytic cracking. Effects of temperature, pressure and space velocity on DME synthesis were studied by biomass-syngas. The results showed that DME yield achieved maximum at 260℃, the yield increased with the increase of reaction pressure. But the yield increased and then decreased with the increase of SV(space velocity). In addition, the rate of methanol synthesis increased if the content of carbon dioxide in the biomasssyngas reduced to 5%, resulting in the increase of the formation rate of DME.
Abstract: The diesel distillate （200℃~360℃）accounting for about 41% in Huadian shale oil has higher sulphur，nitrogen and alkene contents. The main sulphur-containing compounds in the diesel distillate are BTs (benzylthiophene) and DBTs (di benzylthiophene), and the content of basic nitrogen compound in the distillate approaches to that of nonbasic nitrogen compound. In order to produce a clean fuel, the catalytic hydrotreating of diesel fraction from Huadian shale oil was investigated preliminarily in a fixed bed reactor using two kind of commercial catalysts including CoMo/Al2O3 and NiW/Al2O3 at different temperatures, hydrogen pressures, LHSVs (Liquid hourly space velocity) and the ratios of hydrogen/feedstock. The results show that increasing temperature, hydrogen pressure and residence time (reciprocal LHSV) can promote the removal of sulfur and nitrogen, while the hydrogen/feedstock ratio has little influence. The catalyst NiW is more active for hydrodenitrogenation (HDN) than CoMo. Under relative mild conditions, the diesel can be produced from Huadian shale oil distillate with low contents of sulfur, nitrogen and alkene, and lower density and higher cetane number, which can be used as a high quality fuel.
Abstract: CoFe/SBA-15 catalysts for Fischer-Tropsch synthesis were treated in different reduction atmosphere. It was found that the reduction in H2 favored the formation of hexagonal cobalt, and then their catalytic activities were determined by the reduction of cobalt oxide. The presence of Fe3O4 promoted the water gas shift reaction, thus CO2 selectivity increased with the increase of iron content. Compared with the catalysts reduced in H2, the pretreatment in CO led to carbon deposition on cobalt active sites and lowered catalytic activities, but it facilitated the reduction of iron catalysts and led to the increase of olefin to paraffin ratio for C2～4 hydrocarbons. Among them, 20Fe/SBA-15 catalyst showed high activity due to the formation of iron carbides.
Abstract: The mono-, dual- and tri-metallic Pt catalysts for the catalytic dehydrogenation of propane to propylene were prepared by impregnation method using SBA-15 as the support. The fresh catalysts were characterized by some physicochemical characterizations such as BET, H2-TPR, H2-chemical adsorption, and TEM. The amount of deposited carbon on used catalysts was analyzed by O2-pulse technology. The results show that the highest dispersion (about 29%) and the smallest particles size (about 3nm) of Pt are obtained over the trimetallic Pt catalyst. Over the trimetallic catalyst, the loading components can enter the pore of the SBA-15.The tri-metallic Pt catalyst shows the excellent catalytic dehydrogenation performance. The main reasons are the very weak acidity of support, the strong interactions between Pt, promoter, and the support, and the electronic modifications of the Zn to Pt, which can reduce the coke reaction, promote the stability, and selectivity of PtZn-Sn/SBA-15 catalyst in dehydrogenation of propane.
Abstract: The modified HZSM-5 zeolite which contains MgO was prepared by impregnating Mg(NO3)2·6H2O ethanol solution with HZSM-5 and then mixed mechanically with methanol catalyst (MeLi) for LPG synthesis. The effects of MgO were investigated in a fixed bed reactor for LPG synthesis. The result showed that with increase of the MgO addition, the strong acid of HZSM-5 zeolite was decreased. The best mass content of MgO in the HZSM-5 was between 0.25%～1.00%. The hybrid catalyst, which consisted of modified HZSM-5 and MeLi, demonstrated a high activity, high selectivity to the target product C3 and C4 hydrocarbons and long catalyst lifetime.
Abstract: P-HZSM-5 zeolite was successfully synthesized in one step under conventional hydrothermal conditions by using tetraethyl orthosilicate (TEOS), sodium metaaluminate, phosphoric acid (85%), and tetrapropylammonium hydroxide (TPAOH, 25%) as raw materials. The influence of phosphate acid content on the structure, acidity, particle size, and catalytic performance in methanol conversion to propene (MTP) of P-HZSM-5 obtained was investigated. The results indicated that the crystallinity, acidity and particle size of PZSM-5 zeolites are decreased with the increase of phosphoric acid amount used in the synthesis; meanwhile, the crystal symmetry is changed from orthorhombic to monoclinic and the morphology is transformed from spherical into strip. When P-HZSM-5 is used as the catalyst in MTP, these changes exhibited evident influence on the product selectivity. Over the P-HZSM-5 samples obtained with a molar ratio of H3PO4/Al2O3 being 2 and 4, the total yields of ethylene and propylene are close (52.30% and 52.63%, respectively), but the ratio of propene/ethene in the product are quite different (7.02 and 4.12, respectively); it suggests that the product selectivity of MTP can be adjusted by the phosphoric acid content.
Abstract: The hydrocracking of C6~8 mixed chain hydrocarbons(mixed hydrocarbons) and o-xylene over HZSM-5 zeolites with different acidity was studied in a fixed-bed down-flow reactor, and the effects of reaction parameters such as temperature, WHSV and H2/CH volume ratio were investigated after the catalyst reached stable performance. Hydrocracking of mixed hydrocarbons was accompanied by aromatization over HZSM-5 zeolite. The hydrocracking was the main reaction with catalyst of weak acid sites, and the hydrocracking products were main normal alkanes, while both methane and isoalkane were pretty low. However, with HZSM-5 zeolite of strong acid sites, the main reaction was aromatization at the beginning. After a certain time, a stable catalytic performance was reached, presenting similar product selectivity to that of weak acidic HZSM-5. The hydrocracking of mixed hydrocarbons displayed obvious temperature effect, while both the WHSV and H2/CH volume ratio had a small effect. At 380℃,3.0MPa,WHSV of 1.02h-1 and H2/CH volume ratio of 1000, the conversion of mixed hydrocarbons kept above 99% within 100h, and the stable hydrocracking selectivity was above 95%. o-Xylene hydroconversion was found to be a linear combination of three reactions: hydrocracking, isomerization and disproportionation. Over the strong acidic HZSM-5, the yield of hydrocracking products was higher than that of the weak acidic HZSM-5, and over both HZSM-5 the hydrocracking product distribution was similar to that of mixed hydrocarbon hydrocracking. At 380℃, 3.0MPa, WHSV of 1.3h-1 and H2/CH volume ratio of 1000, the stable hydrocracking selectivity was less than 10% for o-xylene hydroconversion.
Abstract: CeO2 samples were prepared by the hydrothermal method. The NiO/CeO2 catalyst was prepared by impregnation. The catalyst was characterized by means of X-ray diffraction(XRD),Scanning Electronic Microscope(SEM) combined by the X-ray energy spectrometer (XES) and BET area. The catalysis properties of the catalysts were tested using a fix bed micro-reactor fitted in a programmable oven. 1.0g catalyst was loaded and the inflow liquid was 0.05mL/min. Results showed that NiO/CeO2 had high activity and stability on low temperature ethanol steam reforming reaction. And, trace amount of Cr, Zn, Cu were added to inhibit CO, CH4 formation and to improve the yield of H2 as well the resistance to carbon deposition greatly. Catalyst stability was achieved in more than 2000h reaction. Cycle test repeated 12 times and showed high stability and good catalytic activity.
Abstract: For the purpose of removing CO to less than 100×10－6 to meet the demand of the proton exchange membrane fuel cells (PEMFC), a bimetallic catalyst 4Ni-2Ru/ZrO2 for CO selective methanation was prepared by homogeneously coating on the foam niekel. The effect of space velocity of feedstock, coating methods and calcination temperature on CO selective methanation was investigated in a microreactor.The relationship between the preparation method and activity of the 4Ni-2Ru/ZrO2 catalyst was also explored by means of X-ray diffraction (XRD) and temperatureprogrammed reduction (TPR). The results indicate that the outlet concentration of CO can be reduced to less than 30×10－6 at 260℃ and the space velocity from 2000h-1 to 6000h-1, with the calcination temperature of 350℃. The outlet concentration of CO can be reduced to 7×10－6 and the CO2 conversion is less than 1.5% as the space velocity is 5000h-1.Because of excellent heat transfer and mass transfer ability, the CO conversion can reach a high level more than 99.6% with the outlet concentration below 50×10－6 even at a high reaction temperature of 300℃.
Abstract: A novel Mn-V-Ce/TiO2 catalyst for selective catalytic reduction (SCR) of nitric oxide was prepared by impregnation method. The effects of reaction temperature, NO and O2 concentrations, NH3/NO ratio and space velocity on Mn-V-Ce/TiO2 catalytic activity were studied. The SCR reaction mechanism on this catalyst was explored with transient response reaction of NO, O2, and NH3. The effect of H2O and SO2 on the catalyst activity was investigated using FT-IR and TG techniques. Experimental results showed that Mn-V-Ce/TiO2 catalyst has good SCR activity at low temperature. High NO conversion of over 99.2% were observed at 150℃ and space velocity 5000h－1. When both SO2 and H2O were added in feed gas, the NO conversion could be kept over 98% at 170℃ for 350min. However, it was observed that the loss of catalytic activity was quick when SO2 was added in feed gas alone; while 8% H2O alone in feed gas had little negative effect on the catalytic activity, which was always over 98% at this situation.The catalyst is expected to be applied in the removal of NOx from exhaust gas without SO2 at low temperature, such as exhaust gas from nitric acid production process or boilers of natural gas.
Abstract: The regeneration characteristics of the Ni-Zn-Fe based oxide desulfurizer prepared by a sol-gel auto-combustion method were investigated. The effect of temperature and the concentration of O2 on the regeneration behaviour were examined in a fixed bed reactor under atmospheric pressure. In addition, the second cycle desulfurization experiments were conducted. XRD, BET and SEM techniques were used to analyze and characterize the fresh and regenerated sorbent. The results show that the sorbent can be basically regenerated at 400℃. The sorbent shows good second cycle sulfidation reactivity after being regenerated with 2% of oxygen concentration at 400℃. X-ray powder diffraction patterns of the sorbent regenerated at 400℃ is almost same as that of fresh sorbent and no sulfate is generated. SEM results show that the sorbent regenerated at 530℃ or with 4% of O2 (vol) concentration has been seriously sintered. Kinetic model tests show that the regeneration process can be well fitted by the shrinking core model. The kinetic controlling steps will transfer with the sorbent conversion. At the initial stage, the regeneration process is controlled by the chemical reaction, which has the activation energy of 27.16kJ/mol and the pre-exponential factor of 4.62m/min. As the reaction proceeds, the product layer is gradually thickened, and the regeneration process gets to being controlled by the diffusion through the reacted layers. The diffusion activation energy is 40.37kJ/mol and preexponential factor is 0.49×10-3m2/min.
Abstract: Methane adsorption equilibrium on Ajax activated carbon and graphitized thermal carbon black BP280 above the critical temperature were studied experimentally and theoretically. Isotherms of adsorption were volumetrically measured at 253K~313K and 0~20.5MPa and isosteric heats of adsorption were determined by adsorption isosteres and temperature dependence of Henry's Law constant. An approximate model for adsorption equilibrium was developed and the maximum adsorption capacity was further determined by Langmuir plot of the adsorption model. The interaction energy among the adsorbed methane molecules was obtained by linearization of the model and fitting with the adsorption data. The results showed that the isosteric heats of methane adsorption on activated carbon and carbon black are 11.9kJ/mol~12.5kJ/mol and 17.5kJ/mol~22.5kJ/mol, respectively; the isosteric heat of adsorption on carbon black varies evenly with the adsorption amount. The maximum adsorption capacity decreases with the increase of temperature; the density of adsorbates is lower than that of liquid methane. The strength of the interaction energy among the adsorbed methane molecules suggests that the adsorbed phase of the supercritical methane is in a state of compressed gas. The adsorption capacity of supercritical methane on a carbonbase adsorbent is largely determined by its specific surface area and micropore volume.
Abstract: The interaction of methoxy (CH3O·) with Rh (111) surface was studied by hybrid-method B3LYP based on density functional theory. The Lanl2dz basis set for Rh atom and the 6-31G(d,p) basis set for O, C and H atoms were used. The Rh13(9,4) cluster was used to simulate the surface. Four typical adsorption sites, top, hcp, bridge and fcc sites, were investigated theoretically and the information about the preferred adsorption geometry and energy of CH3O· species was extracted. The results show that the bridge site is more favorable than the other adsorption sites and the amount of electronic charge transferred from Rh to methoxy species is higher than those on the other sites when CH3O· is bonded to the surface via the oxygen atom. C—O bond is activated and its stretching frequency is red shifted in the process of C—O bond adsorption on Rh (111) surface.
Abstract: The catalyst Pt-Ni supported on carbon with different atomic ratios of Pt to Ni was prepared by the interval microwave method and its performance on the oxygen reduction for direct methanol fuel cell application was investigated. The results show that the active particles of the catalysts prepared in this way were highly dispersed and in small size. The catalyst PtNi/C(3∶1) (with the atomic Pt/Ni ratio being 3) has the smallest particle size; it also exhibits the highest activity for oxygen reduction, no matter whether methanol is present or not in the electrolyte, indicating a small effect of methanol on its catalytic performance for oxygen reduction.
Abstract: The present work focused on the evolution of char surface structure during pyrolysis of sewage sludge. It shows that the char pore structure is developed greatly as the release of volatile. Both high temperature and low temperature pyrolysis increase the pore with a diameter of 3.75nm. The fractal analysis of char surface with N2 adsorption shows that there are two fractal dimensions: FD-1 and FD-2, which are mainly account for the larger pore (>0.86nm) and ultramicropore (<0.86nm) fractal characteristics, respectively. The increase in pyrolysis residence time increases the FD-1 and FD-2 firstly, and then tends to be stable. The FD-2 increases greatly at high temperature pyrolysis compared with that at low temperature, which shows a great development in ultramicropore, while FD-1 is not the case.
Abstract: The pyrolysis weight loss of twisted nematic liquid crystal was studied in nitrogen atmosphere by TGAFTIR. The pyrolysis products from tube furnace experimental system were analyzed GC-MS. The result indicates that the temperature of initial weight loss is 120℃ and that of apparent weight loss is 220℃~430℃. The pyrolysis products are mainly aromatic compounds besides carbon dioxide, which include benzene, phenol, benzenefuran with 1~5 carbon functional groups, polycyclic aromatic hydrocarbons and hydrocarbon organic matters mainly composed of propane. Most of the organic matters are poisonous and harmful and can be harmless by further incinerating.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
