Abstract: The effects of the addition of CaO, temperature and residence time on the conversion and product yields of a highash peat in supercritical water was investigated. The experiments were carried out in an autoclave in the temperature range of 623K~773K at pressure up to 30MPa. At a Ca/C molar ratio of 0.46, almost no CO2 remained in gas phase. It was found that CaO facilitates the extraction of volatile matter from peat and the decomposition of volatile matter to small molecular compounds. Moreover, CaO catalyses the steam reforming reaction of hydrocarbons and the watershift reaction. The addition of KOH might favor the reforming reaction of oil product to hydrogen and carbon dioxide. Furthermore, the yield of oil reaches a maximum at the temperature approximately 723K. A threefold increase in the yield of oil product was observed under 36.5MPa compared with pyrolysis. However, the polar compounds decomposed with the prolongation of reaction time.
Abstract: The conversion of nitrogenous gas products during coal pyrolysis was investigated in the drop tube reactor. Four raw coals and two demineralized coals have been used to pyrolyse at 500℃，700℃，900℃and1100℃. The pyrolysis results indicate that the yields of N2 and NO precursors, such as HCN and NH3, increase with increased temperature. The coal type has significant effect on the yield of nitrogenous gas products. For low rank coal sample, the conversion ratio of fuel nitrogen is higher. The most of fuel nitrogen in high rank coals is built into condensed aromatic structures to form CharN. The mineral substances in coal promote the conversion of fuel nitrogen to N2, but they suppress the conversion of fuel nitrogen to HCN and NH3.
Abstract: Terephthalic acid (TPA) can be obtained in the presence of Zn(Bzo)2 by isomerization of potassium salt of coal acid (water soluble acids, WSA) with organic dispersant having high boiling point in slurry reactor. The effects of initial CO2 pressure, amount of catalyst, reaction time, reaction temperature and the amount of dispersant on the yield of TPA were examined. The optimum conditions of isomerization, with TPA yield of 24.1%, using biphenyl as the dispersant were: temperature 420℃, initial CO2 pressure 3MPa, addition of Zn(Bzo)2 3%, dispersant 60% and reaction time 1h. The optimum conditions, with TPA yield of 25.2%, using pterphenyl as the dispersant were: temperature 380℃, initial CO2 pressure 1MPa, addition of Zn(Bzo)2 3%, and dispersant 60%. The yield of TPA by isomerization of mixture of potassium salts of coal acid and benzoic acid were 60% (use biphenyl as the dispersant) and 62% (use pterphenyl as the dispersant), respectively. The products were analyzed by gas chromatography.
Abstract: Fast pyrolysis of the industrial lignin made by acid precipitation method was investigated at 400℃～700℃，and the liquid pyrolysate obtained was analyzed by Chromatography/Mass Spectrometry (GCMS) to investigate the influence of pyrolysis temperature on the composition of liquid pyrolysate product. The results show that the lignin pyrolysate is composed of singlering phenolic compounds, including phenol(phydroxyphenyl type) as the main component, guaiacol(guaiacyltype) and 2,6dimethoxyphenol(syringyltype), and their methlylic or ethylic derivatives. In the temperature range of 400℃~600℃， the variety of the distribution pattern and the yields of the compounds of pyrolysate is minor. However, the proportion of methoxyphenolic compounds decreases significantly and the proportion of phenol increases markdly when the temperature is up to 600℃~700℃. At 700℃, the relative content of phenol reaches to about 27.81% two and half times higher than that at 400℃. In addition, the formation of aromatic hydrocarbons is enhanced, and small amounts of indene, naphthalene and their derivatives are produced as well.
Abstract: ZSM-5 was insitu synthesized on silica gel by using nbutylamine as the template and characterized by XRD, SEM, FTIR and N2 adsorption. The results indicated that the synthesized sample not only has a composite structure with ZSM-5 and silica gel, but retains the shape of silica gel microsphere. To obtain detailed information on the rules of synthesized chemistry, the effects of SiO2/Al2O3 of initial gel, H2O/SiO2, BuNH2/SiO2, OH-/SiO2, crystallization time and crystallization temperature on ZSM-5 crystallinity were systematically studied. The composite materials were tested in a micro fixedbed reactor, using Daqing Vacuum Gasoline Oil (VGO) as the feedstock. The results showed indicated that the composite structure zeolite yields more light olefins and has good selectivity to light olefins.
Abstract: Room temperature ionic liquids (RTILs) with various anions and cations were synthesized. The effects of the structure of RTILs and reaction conditions on the isomerization of npentane were investigated. The mole ratio of AlCl3 to Et3NHCl plays an important role in the acidity and the catalysis of the RTILs. Normal butyl alcohol was selected as the initiator of the isomerization of npentane and its dosage is about 2.5 weight percent of the npentane. The optimal reaction temperature, reaction time and stir speed are 30℃, 10h and 1500r/min, respectively. Under these conditions, the conversion and the isomerization ratio are 85.66% and 92.86%, respectively.
Abstract: Bifunctional catalysts (M/C) were prepared by impregnating different metals (M) on composite zeolite (C) of HZSM5 and Hβ with different acidities and pore sizes. The physicochemical characteristics of the supports and catalysts were characterized by XRD, NH3TPD and physical adsorption. The catalytic performance of M/C in hydroisomerization and hydroaromatization was evaluated in a microreactor with octane as model compound. The results showed that the composite zeolite C had appropriate distribution of acidity which was beneficial to isomerization and aromatization of octane. The hydrogenation active sites could be offered and the Bronsted and Lewis acid distribution in the catalysts could be adjusted by the modification with metal like Ni, which could enhance the hydroisomerization and hydroaromatization of octane. The hydroisomerization and hydroaromatization behavior depended also on the reaction conditions and the optimized conditions were 320℃， 2.8MPa and LHSV of 2.0h－1.
Abstract: Photosensitized oxidative desulfurization of thiophene in noctane/water extraction system was studied with riboflavin as photosensitizer and O2 in air as oxidant. A 500W high pressure Hg lamp was used as the light source for irradiation and air was introduced by a gas pump for supplying O2. The desulfurization yield of thiophene was 85.4% for a 3h photoirradiation under the conditions with the air flow at 150mL/min, water/oil ratio at 1∶1 and riboflavin concentration at 30μmol/L. The mechanism of photosensitized oxidative of thiophene is 1O2 exited from 3O2 by the addition of riboflavin. Under the above conditions, the photooxidation kinetics of thiophene with O2/ riboflavin is firstorder with a rate constant of 9.10×10-5s-1 and halftime of 2.12h.
Abstract: The mathematical model was studied for the intensification of FCC diesel catalytic oxidation desulfurization by phase transfer catalyst. The mathematical model of diesel desulfurization was established based on the kinetic equations for oxidation reaction of organosulfur compounds, the model equation of intensification for phase transfer catalyst and the equation of sulfides liquidliquid phase equilibrium. It is found that the modeling result of intensification for phase transfer catalyst is precise in the form of exponential function. The model parameters of intensification for phase transfer catalyst, the activation energy and frequency factor of sulfide oxidation reaction, the phase equilibrium constant for solvent extraction are determined through parameter estimation by use of the experimental data of diesel desulfurization. The model prediction shows that the desulfurization degree of FCC diesel changes with the oxidation time. If the oxidation time is short, the desulfurization degree increases with the increase of the amount of phase transfer catalyst. But the desulfurization degree lowers if the oxidation time is longer. The desulfurization degree of FCC diesel increases with increasing the volumetric fraction of oxidation solution or the ratio of extraction solvent to diesel.
Abstract: Deactivation of composite catalyst for onestep dimethyl ether (DME) synthesis in slurry reactor was studied under reaction conditions of 260℃ and 5.0MPa. It was found that instability of Cubased methanol synthesis catalyst led to rapid deactivation of the composite catalyst. Deactivation rate of the Cubased catalyst in slurry reactor was compared with that in fixedbed reactor. The results indicated that harmfulness of water, which is formed in the synthesis of DME, caused the Cubased catalyst to deactivate at a high rate in slurry reactor. Techniques of TPR, XRD, and SEMEDS were used to characterize the reduction behaviors, crystal structures, and surface properties of the catalyst. The results showed that carbon deposition and grain growth of Cu were important reasons for the rapid deactivation of the Cubased catalyst, and no obvious metal loss of Cu was found.
Abstract: Synthesis of dimethyl ether (DME) was carried out in a fixed bed reactor over a bifunctional catalyst CaO/HZSM5+JC207, which was composed of a methanolsynthesis catalyst JC207 (Jingjing Catalyst Plant, China) and a dehydrator HZSM5 (Si/Al = 38) modified with CaO. The effects of zeolite modification with CaO on the performance of the bifunctional catalyst in onestep synthesis of DME were investigated. XRD analysis of the modified zeolite CaO/HZSM5 indicates that CaO is highly dispersed on the zeolite HZSM5 without any new species formed. PyridineIR analysis shows that the modification of HZSM5 with CaO not only brings on significant changes in acid type and acid amount but also turns some of Bronstead acid sites into Lewis acid sites. NH3temperature programming desorption analysis indicates that the number of acid sites on the zeolite surface, especially, that of the strong acid sites decreases with the increase of CaO loading. Modification of zeolite HZSM5 with appropriate dose of CaO turns the strong acid sites into weak or less strong acid sites; such a redistribution of acid sites may be beneficial for the increase of DME selectivity.
Abstract: The effects of adding order of K on the textural properties, reduction behavior, phase transformation, surface basicity and slurry FischerTropsch synthesis (FTS) performances over the spherical Fe-Cu-K-SiO2 catalysts were studied by using N2 physical adsorption, H2 temperatureprogrammed reduction (TPR), CO2 temperatureprogrammed desorption (TPD), Mssbauer spectroscopy and Xray diffraction (XRD). The results indicated that adding order of K could affect the textural properties very slight. The catalysts with later addition of K have stronger surface basicity, which could inhibit the H2 reduction of Fe2O3→Fe3O4 but promote carburization of the catalyst. The catalysts with later addition of K show better reaction stability, higher FTS activity, lower CH4 selectivity and higher selectivity of olefin and heavy hydrocarbon. The results indicate that the later addition of K should be a better choice for Fe-Cu-K-SiO2 catalyst preparation.
Abstract: Influence of reduction method (temperatureprogrammed reduction (TPR) and isothermal reduction) and reduction temperature on the structure and performance of nickelbased catalysts for methane partial oxidation was investigated by means of H2TPR, TEM and catalytic tests. Two catalysts were first prepared at different calcination temperatures (POM-1, calcined at 550℃; POM5, calcined at 950℃). For POM-1 catalyst, the isothermal reduction led to lower reduction degree and smaller nickel crystallites compared with TPR. However, the catalysts with different reduction methods had little difference in the catalytic activity. With increasing isothermal reduction temperature, the reduction degree of POM-1 catalyst decreased, and that of POM5 catalyst increased slightly. The size of nickel crystallites was smaller in POM-5 catalyst than that in POM1 catalyst. With increasing isothermal reduction temperature, there was no marked effect on the reactivity of POM-1, while the hotspot of POM-1 catalyst bed increased. However, the reactivity of POM-5 catalyst increased and the hotspot of POM-5 catalyst bed decreased, with increasing the reduction temperature. The hotspot of catalyst bed was related to the size of nickel crystallites. The larger the size of nickel crystallites was, the higher the hotspot temperature of the catalyst bed; this was perhaps due to the complete oxidation of methane promoted by large nickel crystallites.
Abstract: The effect of alkalineearth promoters on the catalytic properties of supported PtSn/γ-Al2O3 catalysts for longchain paraffin (C10~13) dehydrogenation has been studied by using infrared spectroscopy of adsorbed pyridine (Py-IR), thermalgravimetry (TG), H2 chemisorption and temperatureprogrammed reduction (TPR) combined with microreactor tests. The results show that addition of alkalineearth metal (Mg, Ca, Sr, Ba) to PtSn/γ-Al2O3 can improve its catalytic stability for paraffin dehydrogenation by decreasing the amount of coke formed on the catalysts and increasing the fraction of bare metallic Pt surface after carbon deposition．However, coaddition of alkalineearth metal with higher basicity, e.g. Ba2+, results in stronger interaction between Sn and support, leading to weaker interaction between Pt and Sn and decrease of bare fraction of Pt after carbon deposition. As a result, the PtSnBa/γ-Al2O3 catalyst shows a lower catalytic activity for longchain paraffin dehydrogenation.
Abstract: A series of WP/Al2O3 catalysts with WO3 loading of 30% were prepared by impregnation and reduced in H2 for 4h at different temperatures. The catalysts were characterized by XRD, BET, TG and 31P MASNMR. Over these catalysts, the hydrodenitrogenation (HDN) of carbazole was performed at 633K and 3.0MPa. The results indicated that the active species of WP was accumulated on the support surface at a reduction temperature above 1023K. Only phosphate was detected at the chemical shift of -2.4×10-5 in the catalyst reduced at 923K. WP species was observed at the chemical shift of 2.55×10-4 with low speed of sample rotation in the catalyst reduced at 1073K, while another peak was also detected with the chemical shift of 6.88×10-4 at high speed of sample rotation; this was probably related to a similar structure of —Al—O—W—P owing to the strong interaction of active species with support, which corresponded to the species with the peak at 2θ of 40.44° by XRD. The phosphiding degree of catalyst precursor could be improved by increasing reduction temperature. WP/Al2O3 prepared at 923K exhibited the highest HDN activity with a carbazole HDN conversion of 79%. Three reaction paths of carbazole HDN were derived, which suggested that hydrodenitrogenation was superior to the direct denitrogenation.
Abstract: The chemical reaction in the process of fluoride removal with limestonegypsum from flue gas was described. Based on the twofilm theory, the kinetic model of CaCO3HF reaction was established and analyzed. The effects of reaction temperature, reaction time, HF vaporphase pressure and ratio of Ca/F molar ratio on the fluoride removal reaction were explored. The results show that the conversion of a CaCO3 particle and the fluoride removal efficiency increase as the reaction temperature, the reaction time and HF vaporphase pressure are raised. The molar ratio of Ca/F molar ratio significantly affects the fluoride removal efficiency. It is suggested that twofilm theory model can be used to describe the dynamical behavior of fluoride removal reaction with wet limestone/gypsum. The investigation results are of important significance for studying the mechanisms of gaseous fluoride removal by the typical wet FGD techniques and developing the uniform control technology of coalfired pollutants.
Abstract: The effects of Na additive on the elemental sulfur production during the H2regeneration and on the SO2 sorption capacity for the regenerated Nadoped CuO/Al2O3 were investigated. The results show that the elemental sulfur yield and the SO2 sorption capacity of Na doped CuO/Al2O3 are 1.3 times that of CuO/Al2O3 at 400℃. The addition of Na significantly increases the sulfation of Al2O3 to form Al2(SO4)3 that can be partially regenerated at temperatures lower than 400℃ due to the existence of Na and Cu in the CuO/Al2O3 sorbent.
Abstract: Ironmanganese composite oxides doped with CeO2 as desulfurizer were prepared by coprecipitation and characterized by XRD, SEM, TG and XPS. Its performance in desulfurization was investigated at 325℃ and atmospheric pressure. The results illustrated that CeO2 doping may influence the crystal size, dispersion and surface configuration of ironmanganese composite oxide. As compared with the desulfurizer without CeO2, smaller crystal size and better dispersion can be achieved through CeO2 doping. The content of chemisorbed oxygen on the desulfurizer surface was increased through the addition of 3% CeO2 in ironmanganese composite oxides; its reduction and desulfurization performance were also improved largely. The addition of proper content of CeO2 in ironmanganese composite oxide may increase the active sites for COS adsorption and then enhance its desulfurization activity in COS removal, however, excess amount of CeO2 may cause a negative effect on the desulfurization capacity.
Abstract: By comparing the thermogravimetric curves (TG/DTG) of waste polyethylene and residual oil, the theoretical feasibility of treating waste polyethylene by delayed coking was demonstrated. With the experiments of simulating delayed coking, the reaction characteristics of the simplex waste polyethylene and the waste polyethyleneresidual oil mixtures were studied. The components of fuel oil from the products with simulated distillation were analyzed. The production feasibility of this technology was discussed. In addition, it proposed the industrial application model to achieve the delay coking disposal. The results show that the temperature zone for PE pyrolysis is 350℃~480℃, and that of residue oil is 250℃~460℃. The pyrolysis characteristic of both samples is very similar. The gasoline and diesel oil fraction in liquid product from PE pyrolysis is 62%. The wax oil accounts for 38%. The gas from PE pyrolysis is mainly hydrocarbon with small molecular amounts and hydrogen. The gasoline fraction increases remarkably from delayed cocoking of PE and residue oil than that from pyrolysis of residue oil solely.
Abstract: Formation of residues is a common issue in oxidation of phenol over activated carbon (AC) based materials, which results in the decrease of phenol adsorption capacity and phenol oxidation activity of these materials. Therefore, H2treatment of Cu-Ce/AC (activated carbon supported copper and cerium) subjected to phenol adsorption and oxidation and containing phenol oxidation residues were investigated at elevated temperatures. The H2treatment is found effective to promote decomposition of the residues, to recover phenol adsorption capacity of Cu-Ce/AC, and to reduce phenol desorption in the subsequent phenol oxidation process. In the range of 400℃~600℃, the effectiveness of H2treatment increases with the treatment temperature. The H2treatment, however, can not recover the phenol oxidation activity of Cu-Ce/AC due to agglomeration of the active phase.
Abstract: The pyrolysis behavior of three typical agricultural residues including rice husk, rice straw and wheat straw, was studied at different heating rates(15℃/min, 40℃/min and 100℃/min) in a dynamic nitrogen flow of 80mL/min by TG analysis coupled with Fourier Transform Infrared Spectroscopy (FTIR). The various gaseous products released during biomass pyrolysis were examined. The kinetic parameters under different heating rates were acquired by kinetics analysis. The correlation coefficients are above 0.99. The results show that as heating rate increases the TG curve shifts to low temperature zone and the peak of DTG curve goes to low temperature area accordingly, but the total weight loss and activation energy of pyrolysis fluctuate little. The releasing behavior of gaseous products during pyrolysis of the three samples is similar. CO, CO2, H2O, CH4 and organics are the main gaseous products during biomass pyrolysis. When the heating rate increases, the yield of gaseous products released increases, so does the releasing rate.
Abstract: The convertion of acid oil to biodiesel by use of immobilized Candida lipase absorbed on textile cloth was studied in a fixed bed reactor，which can not only reduce the environmental pollution of acid oil, but also produce a substitute for petroleum diesel. The acid oil mixed with methanol was pumped into three fixed bed reactors in series, and the methanol was added with the molar flow rate same as the acid oil in each reactor. The effects of enzyme content, solvent content, water content, flow rate of reactant and temperature on the enzymatic reaction were analyzed. The result of orthogonal experiments indicates that the optimal transesterification can be performed under the following conditions: immobilized lipase content in acid oil, 20%; hexane content in acid oil, 10%; water content in acid oil, 10%, reaction temperature, 50℃; and flow rate of reactant, 0.08g/min. Under these conditions, the FAME content of 90.18% in the product is obtained. The immobilized lipase can be reused with relatively stable activity after glycerol being removed from the surface. By refining, most of the chemical and physical properties of biodiesel will meet the American and Germany biodiesel standards and exceed the Chinese standard of 0＃ petroleum diesel except for carbon residue， density and kinematic viscosity.
Abstract: CaOloaded solid base used in transesterification of rape oil was prepared by loading CaO on MgO. The base strength and content of the solid base at different preparation conditions were analyzed. The solid base belonged to superbase with the base strength of 27.0 < H- < 37.0. After dipped in 22.4% Ca(AC)2 for 1h and calcined at 700℃ for 24h, highest basic content of the solid base were achieved (H- >9.3, 25.68 mmol/g). The solid base exhibited high catalytic activity in transesterification of rape oil into biodiesel, and the rape oil conversion reached 97.95%.
Abstract: Synthesis of liquefied petroleum gas (LPG) from synthesis gas using hybrid catalyst consisting of methanol synthesis catalyst and USY or ZSM-5 was investigated in a fixed bed reactor. The composition of the hybrid catalyst had great effect on the activity and selectivity of the catalyst. The effect of reaction temperature (260℃～360℃)，GHSV（1500h-1～9000h-1）were investigated. The results showed that the best reaction temperature of bifunctional catalyst which consisted of MeLi and ZSM-5 zeolite is 325℃, and the CO conversion achieved 72.28%. The hybrid catalyst, which consisted of ZSM-5 zeolite and methanol synthesis catalyst, demonstrated a highly activity for the formation of light hydrocarbon and the selectivity for C3 and C4 hydrocarbons was 23.90% and 19.06% respectively.
Abstract: Using natural Na montmorillonite as the host clay, porous silicapillared montmorillonites (SiPILC) were prepared by the template synthesis method. Furthermore, the texture and structure of such composite materials were investigated by using modern several physicochemical techniques such as powder X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Fourier Transformation Infrared Spectra (FTIR), and N2 adsorption/desorption measurements. The results reveal that tetrathylorthosilicate (TEOS) agent has been successfully intercalated into the montmorillonite and the characteristic d001 spacing of SiPILC increases from 1.28nm to 3.15nm. The resultant products with large gallery height possess BJH pore volume as large as 0.30cm3/g, remarkably high BET specific surface area of over 592.0m2/g, pore size distribution in the mesopore region 3.3nm~4.3nm after thermal treatment at 800℃.
Abstract: Circulating entrained bed reactor has many good characteristics as follows: good mass transfer, good solid suspending, little axial backmixing, sufficient contact of different phase, wide adjustable range of gasliquid ratio and high efficiency of catalyst. Study on methanol synthesis has been carried out in the hot model experimental apparatus, and the effects of these factors such as slurry recirculation flow rate，space velocity，concentration of catalyst, the number of nozzle on the methanol synthesis has been investigated in the present study. The results show that the outlet product concentration and spacetime yield increase with slurry recirculation flow rate, concentration of catalyst and the number of nozzle. High space velocity of syngas enhanced the spacetime yield of catalyst，but decreased the outlet product concentration.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
