Abstract: Coals rich in barkinite and semi-fusinite were selected to study their liquefaction behavior as well as their chemical structure, and to seek correlations between the yield of liquefaction products and chemical structural parameters. The liquefaction tests were done in tubing-bomb reactors in a pre-heated sand bath. The samples were characterized by ultimate analysis, proximate analysis, petrographic analysis and 13C -NMR. The results show that barkinite-rich samples contain higher hydrogen and volatile matter contents, and have higher H/C atomic ratios. The chemical structures of the samples used are rich in aromatic carbon. The aromaticity of WEST coal was the highest. The content of methylene carbons of LP, CG and DHB coals is higher than methyl carbon, and is also higher than in the other three coal samples. The LP, CG and DHB coals have higher liquefaction conversions and higher yields of oil. Definite correlations between the yield of oil and the content of methylene carbons and between liquefaction conversion and aromaticity have been observed, which indicates the yield of liquefaction products can be predicted on the basis of solid state 13C-NMR spectral data of coal.
Abstract: Mercury release behavior and speciation during pyrolysis of Datong and Baorixile coals were studied in a temperatureprogrammed tube furnace under N2 atmosphere. The results showed that mercury emission from coal pyrolysis significantly depended on temperature. The release ratio of Hg in coal increased dramatically with increasing temperatures, and more than 92% mercury was released at 600℃. Elemental mercury was the dominant species in the gaseous mercury during coal pyrolysis. The percentage of Hg0 of Datong coal increased firstly, and then decreased, while it reduced gradually for Baorixile coal. Both the rate of Hg release and the percentage of Hg0 rose finitely through the time ranging from 0~60min, and Baorixile coal displayed more significant increase than Datong coal. Higher heating rate promoted the mercury release in coal and enhanced the proportion of Hg2+ in gas; especially for Baorixile coal it reached 19.5%, being apparently higher than that for Datong coal.
Abstract: The high-temperature coal tar sample was separated into 10 narrow oil fractions and one solidphase pitch product by supercritical fluid extraction and fractionation using npentane as solvent at 220℃ and pressure from 5MPa to 15MPa. Results show that the accumulative yields increase with the extract pressure especially at the lower pressures, and the yield increase rate decrease gradually. The total yield of the oil extract is 78.36%, and the raffinate pitch yield is 21.64% which is far below that of the conventional distillation. Elemental analysis and chromatographmass spectrometer analysis show that with the increase of the extraction pressure, the atomic ratio of carbon to hydrogen, the average ring numbers, as well as the average molecular weight of narrow oil fractions increase gradually.
Abstract: The volatility and transformation of Na in raw coals and washed coals by water and 0.1mol/L HCl during coal pyrolysis were investigated in a fixed bed from 400℃ to 700℃ and atmospheric pressure. The semichars were extracted by water and 0.1mol/L HCl, and the forms of Na were divided into three parts: water soluble, acid soluble but water insoluble and acid insoluble. The results show that Na in the raw coal is mostly water soluble NaCl. The Na volatility shows a maximum value between 500℃~550℃ because the organic Na as the carboxylic salt releases as atom Na. However, above 600℃ the Na in acid washed coal transforms into acid soluble but water insoluble, leading to the volatility of Na to increase again. It is found that at higher pyrolysis temperatures the volatile Na in the raw coal is transformed into water soluble; however, the Na in water washed coal may react with SiO2 to transform into acid insoluble Na.
Abstract: The desulphurization performance of nano-CaCO3 during coal combustion was studied by using ZCS-1 intellective sulf-meter, and the effect of additives was also examined. The results show that the desulphurization efficiency is 90% when the temperatures is 900℃ and Ca/S ratio is 2, and more than 50% at 1150℃. Nano-CaCO3 has a higher desulphurization efficiency than the ordinary calcium carbonate. It is indicated that the desulphurization efficiency decreases with the increasing of particle size. The coal type has a great influence on desulphurization due to its different contents and chemical state of sulfur. The temperature is the major factor for the desulphurization. The desulphurization efficiency reaches the highest value at 900℃, but obviously decreases when the temperature is over 1100℃. The SEM and BET results show that nano-CaCO3 can improve the desulphurization process due to its abundant pores. The desulphurization efficiency is increased by adding nano-Al2O3 and nano-ZnO. The nano-Al2O3 additive improves the desulphurization rate by 20% at 1150℃.
Abstract: The combustion characteristics of residues from co-liquefaction of lignite and sawdust under different operation conditions including solvent, temperature, atmosphere, and with/without water added were examined by a thermogravimetric analyzer. The effects of different liquefaction operation conditions on the combustion characteristics of the corresponding residues were investigated through comparing their characteristic parameters such as ignition temperature, peak temperature of maximum weight loss rate and burnout temperature. Based on the TG /DTG profiles, a residue combustion kinetics model was also proposed and the kinetics parameters were obtained by Coats-Redfern method. The results show that the residue with tetralin as solvent has a better combustion reactivity than the residue with toluene as solvent, and the residue from liquefaction at 360℃ has a better combustion reactivity than that at 420℃. Syngas is beneficial to the residue having higher combustion reactivity than hydrogen atmosphere. While adding water to the feedstock during liquefaction lowers the combustion reactivity of the residue compared to the case without water added. The different atomic ratios of H/C, specific surface area and ash content of the residues that arise from the different operation conditions may contribute to the different combustion characteristics of the residues. The kinetics of residue combustion could be described by a threestage second order kinetic model. The activation energy of three stages almost follows the order of high-low-high.
Abstract: The pyrolysis of eucalyptus wood was carried out in a batch reactor to optimize the yield of bio-oil. Effect of various parameters like feed (particle) size, temperature, presence of catalyst and heating rate on the yield of bio-oil was investigated. The optimum conditions for high yield of bio-oil are for the particle size 2mm~5mm (average l/d=12.84/2.03mm) at 450℃ in high heating rate. The reaction kinetics and the quality of bio-oil produced are independent of the presence of different catalysts like mordenite, kaoline clay, fly ash and silica alumina. The physical properties like odour, colour, PH, viscosity, heating value were determined. The FT-IR analysis of bio-oil indicates the presence of different functional groups such as monomeric alcohol, phenol, ketones, aldehydes, carboxylic acid, amines, and nitro compounds. The composition of the bio-oil at different conditions was analyzed using GC-MS and found that the components are temperature dependent but independent of catalysts used.
Abstract: To study biomass pyrolysis mechanism step-pyrolysis experiments were carried out to investigate the pyrolysis products distribution in different temperature ranges using pyrolysis-GC/MS. The results show that pyrolysis products are deeply influenced by chemical components of biomass and pyrolysis temperature. The liquid yield of eucalyptus pyrolysis within 25℃~400℃ is less, which were mainly pyrans and aromatics. The dominant pyrolysis product of eucalyptus is 5,6-dihydro-4-hydroxy-2H-pyran-2-one which decreases with increasing temperature. However, high liquid yield and more species are generated in 450℃~500℃ in form of ketones and aromatics. Corn cob has the similar pyrolysis property with eucalyptus. However, its liquid products are mainly furans such as 2,3-dihydro-benzofuran and 4-hydroxyl-3-methylacetophenone in 25℃~350℃, whereas ketones are the main products in 400℃~450℃. Different liquid products are produced from the major chemical components of biomass in different temperature ranges. It is possible to carry out a selective pyrolysis for the major chemical components of biomass to achieve efficiently utilization of biomass resource.
Abstract: The characteristics of pyrolytic oil from fast pyrolysis of corncob in a built-in fast pyrolysis fixed-bed reactor were studied through column chromatographic separation. It is shown that the pyrolysis temperature has a great effect on the yield and the compositions of the bio-oil. The GC chromatogram of the aliphatic fraction show that the carbon distributions are between C12~34. Carbon distributions of the aliphatic fraction are similar to those in diesel fuel. The bio-oil obtained at 600℃ was analyzed using FT-IR and 1H-NMR. The chemical characterization shows that the bio-oil from corncob may be potentially valuable as a fuel and chemical feedstock.
Abstract: Triglyceride is a kind of renewable sources and widely exists in animals and plants. The cracking properties of triglyceride were analyzed through TG, DTG and DSC using soybean oil as material. The catalysis mechanism was changed with base catalyst. The results show that the fuel properties of cracking product are improved because the base catalyst can promote decarboxylation reaction in cracking process. The temperature of cracking of soybean oil is about 400℃~500℃. The suitable cracking technology is flash pyrolysis in a trickle bed reactor. Several kinds of catalysts such as Al2O3, MCM-41 and Na2CO3 were compared. Under the optimum conditions, the obtained cracking oil shows low acid value (30mg KOH/g). The cracking oil characterized by FTIR and GC-MS shows the formation of olefins, paraffins. The heat value of pyrolytic oil is 43MJ/kg and its dynamic viscosity and density is 2.6mm2/s and 0.84g/cm3, respectively.
Abstract: The reaction behavior of both catalytic pyrolysis and thermal pyrolysis of HGO (heavy gas oil) and LGO (light gas oil) derived from Canadian synthetic crude oil was investigated in a confined fluidized bed reactor. For the catalytic pyrolysis of HGO and LGO, the yields of total light olefins (ethylene, propylene and butylene) reach a maximum at about 660℃ (33.8% and 35.6%, respectively). The thermal pyrolysis of HGO and LGO is in high extent; the conversions of HGO and LGO at 700℃ reach 66.7% and 76.3%, respectively. For the thermal pyrolysis of HGO, the yield of total light olefins shows a maximum of 27.9% at 680℃. Through comparing the gas product yield of catalytic pyrolysis with that of thermal pyrolysis, it was found that the addition of the catalyst accelerates the formation of ethylene and liquefied petroleum gas (LPG), and simultaneously restrains the formation of methane and ethane. Current results suggested that methane and ethane are mainly produced by the free radical reaction, while ethylene and LPG are produced by both the free radical reaction and the carbonium ion reaction.
Abstract: Natural gas hydrate can be easily formed from the water base drilling fluid during the deep water drilling, which will affect the normal progress of drilling operation. To solve the problem, a reaction equipment was designed and developed, which can simulate the temperature and pressure conditions of deep water drilling .The effects of additives used in water drilling fluids including CPAM, 80A51, HPAM, FA367, NW-1, MP-Ⅱ, HEC, MC, XY-27, SMT, FCLS, EG600, HCOONa, HCOOK and NaCl on natural gas hydrate formation were investigated. And the subcooling degree of drilling fluid system was obtained. The result shows that CPAM, 80A51,HPAM, FA367, NW-1, SMP-Ⅱ, HEC, CMC, XY-27, EG600, HCOONa, HCOOK, NaCl and KCl can inhibit the formation of natural gas hydrate to some degree, but SMT and FCLS can help the formation of natural gas hydrate faintly in water base drilling fluids. The inhibition of the ion species of polymer additives on gas hydrate can be ignored.
Abstract: An experimental investigation on CO2 reforming of CH4 to synthesis gas was performed by a novel atmospheric pressure plasma jet, which is initiated by an alternating current of 50Hz and a high ratio transformer. The plasma jet proved to be a stable and uniform atmospheric pressure discharge that held the advantages of both thermal and non-thermal plasma. The effects of discharge distance, CH4/CO2 mol ratio in the feed, feed flow rate and discharge power on the reforming reaction were investigated. The results showed that the products of the reforming reaction are simple, including H2, CO, a small amount of H2O and carbon powder. The optimal discharge distance between two electrodes is 9mm and the optimal CH4/CO2 mol ratio is 4/6. When the flow rate is 1000mL/min and the discharge power is 88.4W, the conversions of CH4 and CO2 are 94.99% and 87.23%, respectively, which are higher than those via other plasmas. The conversions of CH4 and CO2 increase with increasing the discharge power and decrease with increasing the flow rate. Current process is more advantageous in treatment capacity and conversion ability for carbon dioxide reforming of methane than other plasma systems.
Abstract: The production of hydrogen-rich gas by plasma reforming of DME was conducted in a self-made three-cavity reformer at atmospheric pressure and ambient temperature. The effects of reformer structure parameters, electrode material, heat transfer characteristic, and operation parameters on the gas composition and hydrogen yield were investigated. The results indicated that with the increase of pulse duty ratio and arc frequency, the yield of hydrogen increases first and reaches a maximum when the pulse duty ratio and arc frequency are 80% and 170Hz, respectively. The yield of hydrogen increases with the increase of anode diameter and discharge cavity number, but decreases with the increase of anodic heat transfer characteristic. The optimal air/DME ratio is 3.5 to get the highest hydrogen yield. Hydrogen yield and hydrogen concentration in the product can be enhanced by using iridium anodes, cuprum cathodes and reasonable radius of cavities.
Abstract: Alkylation of benzene with ethanol has been investigated over Fe,Ni,Ti ion exchanged modified HZSM-5 catalysts. The catalysts were characterized by NH3-TPD,PyIR,XRD,BET,ICP. The Ti loading amount is the most and the Ni loading amount is the least. Modification of Ni enhanced the strong acid and depressed the moderate acid. After modified by Fe the weak and moderate acid increased and the strong acid decreased. With modification of Ti, the weak and moderate acid did not change significantly while the strong acid increased .The ratio of B acid and L acid of Ni-ZSM-5 decreased, the Fe-HZSM-5 and Ti-HZSM-5 increased. The pore diameter of and the BET surface area decreased after Fe and Ti modification. The reaction results showed that the ethylbenzene selectivity of the catalysts decreased a little after modification, while the ethylbenzene yield and benzene conversion increased. In conclusion, the Fe-HZSM-5 and Ti-HZSM-5 were the proper catalysts for the title reaction.
Abstract: Monometallic catalyst Pt/SAPO-11 was prepared by impregnation method. Bimetallic catalysts including LaPt/SAPO-11, CePt/SAPO-11 and SnPt/SAPO-11 were prepared by sequential impregnation method. X-ray diffraction (XRD), nitrogen adsorption, temperatureprogrammed desorption of ammonia (NH3-TPD), chemisorption of hydrogen and Fourier transform infrared spectroscopy (FT-IR) techniques were employed to characterize the catalyst. The results showed that BET surface areas, microporous volume, the amount of Bronsted acid and the total acidity of catalysts decreased slightly with the addition of metal additive La, Ce or Sn. However, the addition could lead to an increase in the amount of Lewis acid. Meanwhile, the introduction of the additive was feasible to promote the dispersity of Pt. In addition, the catalytic performances of catalysts for the hydroisomerization of n-heptane were studied. At 360℃, addition of La and Ce to Pt/SAPO-11 catalyst could increase its conversion of n-heptane from 65.14% to 77.40% and 78.12% respectively, and yield of i-C7 from 61.67% to 69.72% and 68.48%, respectively. While the conversion of n-heptane and yield of i-C7 over SnPt/SAPO-11 catalyst was 63.22% and 59.09% respectively.
Abstract: Three Ni-based catalysts with or without MgO or CaO promoters were prepared by co-impregnation method and their properties for methane steam reforming to syngas were studied in a fixedbed reactor. Results showed that CaO promoter on Ni-based catalyst had the best performance with 96.95% methane conversion, 68.93% CO selectivity and 73.58% H2 yield at the condition of n(H2O)/n(CH4)/n(N2)=2.86/1/3.28 with a GHSV 1800h－1 at 700℃. Results from XRD and H2-TPR experiments showed that the addition of CaO enhanced the active component NiO, and had the best reducibility and dispersibility. The type of carbonaceous species Cγ, which may cause catalyst deactivation, wasn't found on the Ni-CaO/Al2O3 catalyst after 10h reaction by using TGA techniques.
Abstract: Ceria-alumina composite oxides with different ceria loadings (5%, 10%, 20%, 25%, and 30%) were prepared by impregnation method and deposition-precipitation method, respectively. Gold catalysts supported on these oxides were used to water gas shift reaction. All samples were characterized by nitrogen adsorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and hydrogen temperatureprogrammed reduction (H2-TPR). It is found that the preparation method and calcination temperature of ceria-alumina oxides have a marked influence on their surface areas, porous structures and the catalytic performances of supported gold catalysts for water gas shift reaction. Ceria-alumina oxides prepared with impregnation method gave larger ceria particle size and high catalytic activity than those prepared with depositionprecipitation method. Gold catalyst supported on 20%CeO2-Al2O3 oxide calcined at 500℃ showed the highest activity. CO conversion reached 78.1% at 250℃ and atmospheric pressure.
Abstract: The supported Ru-based catalyst promoted by lanthanum oxide was prepared by impregnating the SBA-15 carrier with aqueous Ru(Ac)3 and La(NO3)3 solution using vacuum absorbing method. The as-prepared catalysts were investigated by means of X-ray powder diffraction, transmission electron microscopy, and catalytic activity measurement for water-gas shift reaction. SBA-15 silica synthesized with P123 by reaction at 80℃ for 24h proved to be a mesoporous product with a mean pore size of 8nm. Metallic Ru was well dispersed on SBA-15 carrier as nanoparticles in 1nm size. The results indicated that the optimized content of ruthenium and lanthanum oxide in catalyst is 4% and 8%, respectively. Under conditions of SV=2000h-1 and Vsteam/Vgas=1, the CO conversion is 56% at 255℃ and 98% at 265℃ for catalyst R4L8/SBA-15.
Abstract: Experimental research on biomass derived gas reburning for N2O removal was carried out in a small scale fluidized bed combustor. The effects of reburning position, the height of material bed, the rate of reburning fuel, the initial oxygen content of flue gas and reaction temperature on N2O emission were investigated. The results show that the decomposition rate of N2O with the reburning of biomass derived gas at nozzle B (200mm over the air distributor) is hiher than that at nozzle A (100mm higher than air distributor). When 1% of biomass derived gas with regard to N2O/N2 mixture is ejected from nozzle B at 850℃ of bed temperature and 10mm of bed height, N2O is decomposed nearly completely.
Abstract: Experiments were conducted in a small self-designed bubbling apparatus to investigate the effect of acid additives including hydrochloric acid, sulfuric acid, phosphoric acid, citric acid and boric acid on the wet flue gas desulfurization by ethylenediamine. The results show that the acid additives can observably increase the available absorption capacity of the absorbents. The available absorption capacity of ethylenediamine/boric acid (266mg/L) and ethylenediamine/phosphoric acid (269mg/L) are higher, and have good pH buffering ability. It is found that the desulfurization efficiency of ethylenediamine sharply decreases with time. After adding acid additives, a higher desulfurization efficiency can be maintained for a long time. The recovery of SO2 in ethylenediamine/boric acid, ethylenediamine/phosphoric acid and ethylenediamine/citric acid was studied. All the mean SO2 removal efficiency of the three absorbents in ten cycles can reach 99%, and the SO2 desorption efficiency follows the order: ethylenediamine/boric acid＞ethylenediamine/phosphoric acid＞ethylenediamine/citric acid. According to the experimental results, boric acid and phosphoric acid seem to be the most promising additives.
Abstract: A MgO/Al2O3 adsorbent prepared with impregnation method was characterized by using N2-adsorption and XRD, and its CO2 kinetic sorption properties were studied by means of breakthrough analysis in a fixed bed flow adsorber. The effects of MgO loadings, adsorption temperatures and gas flow rates were investigated. The stability and regenerative abilities were studied by cyclic experiment. The results indicated that the optimal loading of MgO was 10%, the maximal adsorption capacities were achieved when the temperature was 50℃ and the gas flow rate was 45mL/min. The texture properties as well as the adsorption capacity were maintained in multiple cycles, thus the MgO/Al2O3 adsorbent could be considered as a potential CO2 adsorption in industrial application.
Abstract: Adsorption behavior of a number of aromatic compounds on an activated carbon was investigated in static state system, and the adsorption data were fitted using Langmuir model. It is found that adsorption behavior of aromatics on activated carbon is approximately described by Langmuir model, solubility and/or polarity of the compounds have major influences on the adsorption, and π－π dispersion interaction plays little role in the adsorption.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
