Abstract: The facility for analysis of chemical thermodynamics (F*A*C*T) based on the Gibbs energy minimization principle was used to characterize the evaporation of mineral elements of coal in O2/CO2 recycle combustion. The effects of atmosphere and temperature on the speciation of mineral species were discussed. The results show that Na(K)Cl(g), FeO(g) and SiO(g) are dominant gaseous species of mineral elements. The dominant species of mineral elements in flue gases depend on both the combustion conditions (reducing or oxidizing) and the atmosphere. In O2/CO2 mixture combustion, the evaporation rate of mineral elements is much lower than that in air combustion, especially in reducing atmosphere. The total evaporation of mineral elements in O2/CO2 atmosphere and air combustion under reducing conditions is 4.46% and 9.65%, respectively,up to temperature of 2400 K. The calculation values are consistent with the experiment values. The decrease of mineral elements evaporation is helpful to suppress the formation of fine particle matter and the tendency of initial ash deposition.
Abstract: The catalytic effects of alkali, alkaline earth and transition metals on pyrolysis of a lignite and a bituminous coal were investigated using TG-FTIR. The results indicate that the orders of catalytic effect on the pyrolysis of lignite and bituminous coals are Ni>Fe～Ca>K and Ca～Fe>Ni>K, respectively. The maximal increments of conversion for the lignite and the bituminous coal are 10.1% and 6.4% respectively with catalysts loaded. The CH4 yield of the bituminous coal is larger than that of the lignite. The increase in yield of CO2, H2O, CH4 and CO is dependent on the catalysts, which are closely related to temperature region and coal ranks.
Abstract: Wujiaping coal pyrolysis was investigated in a fluidized bed reactor under atmospheres of 3.0%, 5.6% and 8.7% O2N2 at the temperatures ranging from 500℃ to 800℃ and the residence time of 30min. GC and flue gas analyzer were used to measure the sulfurcontaining gases . It is found that the main forms of sulfurcontaining gases are H2S, COS and SO2, which have similar evolution rule: the evolution rate increases quickly with increasing temperature and oxygen content. The ratio of H2S and COS to the total sulfur amount in pyrolysis gas decreases much under 5.6% O2N2 compared with that under 3.0% O2N2, however, under 8.7% O2N2, it increases greatly. But the effect of oxygen content on SO2 evolution is contrary to that of H2S and COS. Under 5.6% O2N2, above 93% of total sulfur in the pyrolysis gas is SO2, but under 8.7% O2N2 the ratio decreases remarkably to 56%. This suggests that under 8.7% O2N2, more oxygen takes part in the reactions of C—C bonds cleavage, which results in the formation of more CO and higher ratio of CO/SO2 than that under 5.6% O2N2.
Abstract: The occurrence mode of chlorine in solid products from copyrolysis of coal and waste plastic was studied by IR and TGMS. In addition, the emission characteristic of those solid products during combustion was studied. The results indicates that when copyrolysis temperature is below 600℃, there are some organic as well as inorganic chlorine compounds in coke; when the temperature is above 600℃, there is only inorganic one in the coke. The emission ratio of chlorine is relative to combustion temperature, the copyrolysing temperature as well as the percentage of PVC. The emission ratio of chlorine increases with the rising temperature of combustion. When the combustion temperature is 900℃, the emission ratio is up to 94%. On the contrary, the emission ratio is lower for the solid product from higher copyrolysis temperature as the combustion temperature is the same. The highest chlorine emission ratio from pyrolysis at 400℃ is 99.86%, but that from 1000℃ pyrolysis is 94.35%.
Abstract: Sulphoaluminate calcium is not only a very desulfuration product at high temperature，but also a primary material of a new special type of cement. The formation process of sulphoaluminate calcium at different temperatures and the influence of additive on the formation of sulphoaluminate calcium were studied by XRD, SEM and intelligent sulfur measuring apparatus(KZDL4M). The results indicate that the sulphoaluminate calcium can be formed at the temperature ranging from 1150℃ to 1450℃，12CaO·7Al2O3 can be produced simultaneously. When the temperature is higher than 1400℃， the sulphoaluminate calcium decomposing to 3CaO·Al2O3. MgO promotes the formation of sulphoaluminate calcium. Fe2O3 can promote the formation of sulphoaluminate calcium under low temperature， whereas it will promote its decomposition under high temperature. SiO2 will restrain the decomposition of CaSO4 effectively under high temperature， which makes against the formation of sulphoaluminate calcium.
Abstract: In this paper, through the CFD modeling of the ashagglomerated fluidized bed gasifier, the gas molar concentration distributions in the bed with the influences of the oxygen flow rate from the central nozzle, the steam flow rate from the distributor and the pressure of the bed are studied. The effects of the different operation conditions on the different reactions are deeply explored and then the law about how the operation conditions work on the gas concentrations in the gasifier can be explained.
Abstract: The influences of mesoporous materials like MCM41/SBA15 as catalysts on pyrolytic liquids from wood were investigated. The pyrolysis oil was analyzed by elemental analyzer, size exclusion chromatography and gas chromatographymass spectrometry. Elemental analysis for the upgraded oils shows a decreasing trend for oxygen content of the oil, which confirmed that the mesoporous materials is a kind of effective substances for removing oxygen from the pyrolysis oil. After catalysis upgrading the proportion of the long chain compounds is obviously diminished, while the aromatic compounds markedly increase in pyrolytic oil. The analysis from GCMS show that the content of the compounds such as pentadecane, hexadecane, dimethyjbenzene, naphthalene, etc. markedly increase, and methylphenol, 2methoxy4methylphenol, 2methoxy4ropylphenol, etc. decreases.
Abstract: Biooil production from fast pyrolysis of biomass has aroused great attentions and interests extensively in recent years because the excess consumption of fossil fuels and high efficiency of biomass pyrolysis technique. The product of fast pyrolysis of biomass, biooil, has deleterious properties of high viscosity, thermal instability, corrosiveness and chemical complexity, which results in many obstacles to their applications. A novel upgrading process, selective esterification over solid acid catalysts, were suggested. With model compounds of acetic acid and ethanol reacted to get ethyl acetate, solid acid catalysts 40％SiO/TiO2SO42－was selected as the best one for esterification activity. Upgrading of biooil over this solid acid catalyst in the subsequent experiment was investigated. The heating value increases by 50.7%. Dynamic viscosity is only one tenth of that of the original. Density of biooil is lowered by 22.6%. GC-MS analysis shows that organic acids are converted to esters such as formate, acetate et al over the solid acid by undergoing catalytic esterification. All of those proved that the properties of biooil are improved. However, the dehydration characteristic of 3A molecular sieve is not good and it has little effect on the properties of acidity, density and viscosity.
Abstract: It has been generally accepted that internal diffusion in catalyst has become increasingly important for Residue Fluid Catalytic Cracking (RFCC) because of the large molecules of residue, high reaction temperature and the short contact time between the catalyst and residue during the catalytic process. The creation of mesopores and macropores inside RFCC catalyst is considered as an effective approach to improve the accessibility and catalyst performance. In this paper, polystyrene particles were used as template to introduce macropores to the RFCC catalysts. The pore structure was characterized by SEM and N2 adsorption. The catalytic cracking performance of the RFCC catalysts with macroporous structure was tested in a fixedbed tubular reactor using Daqing atmospheric residue as feed. The macroporous catalysts exhibit better catalytic performance, higher conversion, and higher yield of light oil than the controller catalyst.
Abstract: Quantum chemical calculations have been performed on the structure of petroleum gums. The structures of the single layer (SG), double layers (DG) and triple layers (TG) for the petroleum gums were obtained. The parts of aromatic rings and alicyclic rings are approximate plane structures, while alkyl side chains extend from the plane. The distances of C—C bonds in aromatic rings, alicyclic rings and alkyl side chains of the gum are all shorter than those in benzene ring, naphthenes and alkyl group. The bonds in alkyl side chains are weaker than those in aromatic rings and alicyclic rings. This suggests that the bonds in alkyl side chains can be broken easily with proper catalysts. DG and TG are slightly different in bond distances, bond angles and net charges. Moreover, hydrogen bonds (H-bonds) are found between layers. The action energies in DG and TG are -22.8416kJ/mol and -43.8455kJ/mol, respectively. The large bulks of DG and TG may cause obstructs for their diffusion into the holes of molecular sieves.
Abstract: Ni promoter was introduced into the coprecipitated FeMnK/SiO2 FischerTropsch synthesis catalysts. The effects of Ni on catalyst structural properties, reduction and carburization behaviors were studied by N2 physical adsorption, XRD, Mssbauer spectroscopy, temperature programmed reduction (TPR) in H2 and CO, and isothermal reduction in syngas. The results indicate that Ni promoter increases the BET surface areas of catalysts and is favorable to the formation of smaller crystallite particles. H2TPR results show that Ni decreases the reduction temperature of catalysts, and CO-TPR results show that Ni facilitates the oxygen removal and increases the carbon introduction content. These effects contribute to a significant improvement of the reduction and carburization behaviors of catalysts in syngas, and the promotion effect increases with the Ni loading content.
Abstract: Two kinds of immobilized Ru catalysts were synthesized by anchoring different ruthenium complexes on the functionalized mesoporous MCM-41 and then characterized with elemental analysis, atomic absorption spectrophotometer, UVVis and FT-IR. Hydrogenation of carbon dioxide to formate was investigated over these catalysts in CO2expanded solvent. The effects of solvents and bases on the catalyst activity were also examined. These two catalysts are different in their activities and stabilities, especially at lower temperature and hydrogen partial pressure. High formate yield is obtained and no byproduct is detected. The immobilized Ru catalysts are promising in industry due to the facility in catalyst separation and reuse.
Abstract: Vapor phase carbonylation of methanol was investigated over NiPd/AC catalyst under the conditions of 260℃, 1.5MPa, CO/CH3OH/CH3I(mol ratio)20/19/1, W/F=7.5g·h·mol-1. The structure and surface property of the fresh and deactivated NiPd/AC catalysts were characterized by BET specific surface area, PyrolysisFTIR and XPS. It was found that the deactivation at the primary step appeared to be consistent with a strong adsorption of reaction products that plugged the catalyst pores and leaded to diffusion limitation. With the proceeding of the reaction, the carbonylation active site Ni migrated gradually and enriched on the catalyst surface, resulting in easy carbon deposition, which enhanced the deactivation of the catalyst. Further investigation revealed that the carbon deposited on the catalyst surface has graphite structure or similar to graphite structure.
Abstract: The Au/αFe2O3MOxcatalysts(M=Zr、Al、Mg、Ca、Ba) prepared by coprecipitation method were characterized by BET ,XRD, H2-TPR and CO2-TPD-MS.The catalytic performance for lowtemperature watergas shift reaction(WGSR) in H2 rich gas was investigated. It was found that the activity and stability of Au/αFe2O3MOxwas strongly dependent on the type of additive. Among the tested samples, the Au/αFe2O3 catalyst modified by ZrO2 or Al2O3 showed highest activity and stability. On the contrary, the modification by MgO,CaO and BaO resulted in an activity decrease. The structure and surface analyses revealed that zirconia added to the the Au/αFe2O3 catalyst increased the surface area, decreased crystallite size of support, and limited the growth of the crystallite size of support during the catalytic reaction. The results indicated that addition of the promoter zirconia and alumina, changed the structure and performances of the support and resulted in higher activity and stability.
Abstract: The pyrolysis properties of three tire samples were investigated by means of nonisothermal thermogravimetric analysis in N2 of high purity (99.99%) at heating rates ranging from 5K/min to 20K/min. The pyrolysis process of the samples from outer cover has two distinct phases with increasing temperature because of complex rubber ingredients in outer cover. The major rubber ingredient in inner tube is single and the pyrolysis process of the sample from inner tube has only one distinct phase. The temperature range for distinct weight loss of all three samples is from 600K to 800K, which corresponds to a tire conversion range of 0.2~0.8. The pyrolysis of the three samples can be described by the firstorder kinetic model and the related kinetics parameters of the samples pyrolysis were determined.
Abstract: The sampler for PM10 from atmosphere was refit, with which a set of PM10 (inhaled particulate matter) sampling system applied in flue gas from waste incinerators was established. With the sampling system PM10 from 3 different incinerators was sampled respectively. 16 kinds of polycyclic aromatic hydrocarbons (PAHs) in PM10 were quantified by GC-MS. The mass fraction of PAHs in PM10 and the concentration of PAHs in flue were obtained. The PAHs with different rings were compared. And the toxic parameters of PAHs were analyzed. The result show that most of the PAHs in PM10 is of 4, 5, and 6 rings, while only little PAHs is of 3 and 2 rings. Compared with coalfired power plant, the concentration and toxic parameters of PAHs emitted from waste incinerators are higher.
Abstract: The depolymerization of polytrimethylene terephthalate in methanol was carried out in an autoclave reactor. The effects of reaction temperature and reaction time on the reaction were investigated. The results showed that the yields of monomers were dependent on the reaction temperature and reaction time. The variation of carboxymethl group in the solidproducts were analyzed by gel permeation chromatograph. A kinetic model was used to describe the reaction, which fitted well with the experimental data. The dependence of rate constant on the reaction temperature was correlated by the Arrhenius plot giving the activation energy of 87.8kJ/mol.
Abstract: To investigate the enhancement of impregnation of sodium carbonate and relative humidity of the feed on the adsorption of low concentration H2S on activated carbon under anaerobic conditions at ambient temperature, the experiments of dynamic adsorption of hydrogen sulfide on activated carbon and the impregnated one were carried out under different relative humidity. The effect of temperature on adsorption processes was also investigated. The results show that the adsorption equilibrium data were fitted well with the Freundlich Isotherm. Compared with the activated carbon，the BET surface area and the micropore volume of the impregnated ones were reduced slightly while the adsorption capacity of H2S increased. This indicates that H2S reacts with the impregnant on the surface of activated carbon. When relative humidity is increased, the adsorption capacity is evidently enhanced on both of activated carbon and the impregnated one. The equilibrium adsorption capacity decreases and the breakthrough time reduce with the temperature increasing.
Abstract: The synthesis of diphenyl carbonate (DPC) by oxidative carbonylation of phenol was studied. Fe(III)EDTA was found to be efficient in PdCl2/Fe(III)EDTA/1,4benzoquinone (BQ)/ tetrabutylammonium bromide (TBAB) catalyst system. The role of each component in the catalyst system was discussed. A catalytic mechanism was proposed. The optimum reaction temperature for oxidative carbonylation of phenol to DPC was 100℃～120℃. When the reaction was catalyzed over PdCl2/Fe(III)EDTA/BQ/Bu4NBr, at 100℃，p CO=2.0MPa，pO2=0.5MPa，phenol 0.5mol, PdCl2 0.28mmol, nPdCl2)∶n(redox cocat.)∶n(BQ)∶n(Bu4NBr)=1∶1∶10∶40, 4 A molecular sieve 5.0g, 4h, the yield and selectivity of DPC were 8.35% and 97.5% respectively. High pressure was favorable for the production of DPC.
Abstract: Silicoaluminophosphate molecular sieves SAPO-5, SAPO-11 and SAPO-41 were synthesized and characterized by XRD, IR and pyridine adsorption IR. Their catalytic performances in isomerization of m-xylene were investigated. SAPO-11 owns the largest number of acid sites, particularly the strong Brnsted acid sites, and then exhibits the highest activity and selectivity to p-xylene; whereas low activity and selectivity were obtained over SAPO5 catalyst. The sequence of activity and the number of strong Brnsted acid sites of the SAPOs followed SAPO-5＜SAPO-41≈SAPO-11. Both SAPO-11 and SAPO-41 produce predominantly the p-xylene isomer due to their medium size pores.
Abstract: The roles of such classical hydrogen-donor solvents as tetralin, decahydronaphthalene, dihydrophenanthrene and dihydroanthracene in visbreaking of vacuum residue were examined. It revealed that the effect of the hydrogendonor solvents could be ranked as dihydrophenanthrene≈dihydroanthracene> tetralin> dihydrophenanthrene and that the appropriate amount added was around 15％. Further studies showed that the coke formation can be greatly reduced by adding hydrogen-donor solvents, consequently the hydrogen-donor approach allowed the operation of visbreaking at higher severity. The effect of hydrogen could be negligible when the hydrogen pressure was lower than 2.5MPa.
Abstract: The surface of activated carbon (AC) was improved with chemical modification by HNO3 oxidation and loading with metallic ions. The adsorption property for organic sulfur complexes in gasoline was studied. The results show that the surface acidity groups of activated carbon increase considerably by HNO3 treatment. The carboxyl groups increase 11~17 times by 4mol/L~8mol/L nitric acid than by 0.5mol/L one. The BET surface area (SBET) of AC decreases from 667.6m2·g-1 to 372m2·g-1. After loading with metallic ions the SBET of AC decreases in different extent. The adsorbing ability of a sulfur compound will be better by choose of loading a specific metallic ions based on the characters of organic sulfur complexes. The AC loading with Fe3+ exhibits a good adsorption performance, with removal ratio of 85.1%, to sulfur complexes of thiophene that is difficult to be removed from gasoline.
Abstract: Enrichment of organic sulfur compounds in gasoline was investigated with acid extracting agent (sulfuric acid + phosphoric acid + water) and solvent n-hexane. Sulfides and thiophene derivatives in gasoline are extracted into n-hexane; the concentration of sulfur compounds enriched in n-hexane can be higher than 12 times of the sulfur concentration in gasoline sample. Thus, sulfides and thiophene derivatives enriched in n-hexane can be analyzed easily by using a gas chromatography with flame photometric detector (GC-FPD) and a gas chromatographymass spectrometry (GC-MS) because of less interference of hydrocarbon. In this work, 52 sulfur compounds were detected with GC-FPD, of which 14 sulfur compounds with determinate structures were identified with GC-MS.
Abstract: Mesoporous molecular sieves AlMCM41 with 〖ＷＴＢＸ〗n〖ＷＴＢ１〗(SiO2)/〖ＷＴＢＸ〗n〖ＷＴＢ１〗(Al2O3) ratio being 20, 50 and 100 were prepared. As proved by Xray diffraction (XRD) patterns and the N2 physical sorption, the assynthesized AlMCM41 exhibited typical hexagonal structure, large surface areas and narrow pore distribution. The performance of HAlMCM41 as catalyst for tertbutylation of pcresol with methyl tertbutylether (MTBE) was then investigated. The effects of temperature, weight hourly space velocity (WHSV) and the feed ratio 〖ＷＴＢＸ〗n〖ＷＴＢ１〗(MTBE)/〖ＷＴＢＸ〗n〖ＷＴＢ１〗(pcresol) on pcresol conversion and product selectivity were examined. The results showed that mesoporous HAlMCM41 molecular sieves (n-SiO2)/n-Al2O3) = 20) is an efficient catalyst with high activity, selectivity and stability for the synthesis of 2tertbutyl p-cresol from p-cresol and MTBE by tertbutylation.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
