Abstract: Modes of iodine occurrence in bituminous coal and anthracite were investigated by using inductively coupled plasma mass spectrometry (ICP-MS) and sequential chemical extraction. The results showed that iodine in both these coals occurs in a descending order of organic, bound with Fe-Mn oxide, water-soluble, residue, ion exchangeable, and the fraction bound to carbonate. In bituminous coal and anthracite, the mean relative content values are 47.4%±3.28% and 43.3%±2.42% for iodine bound to organic matter, 36.8%±3.70% and 34.6%±4.77% for the iodine bound to Fe-Mn oxides, respectively; the amounts of water soluble and ion exchangeable iodine are 10.3%±3.00% and 14.3%±3.37%, respectively; the potential leachable rates of iodine are 10.9% and 16.0%, and potential leachable iodine contents 0.9 μg/g and 1.2 μg/g, respectively. These results suggested that iodine leaching from both these coals can lead to an increase of iodine concentration in surface water at the supergene conditions; the effect of iodine in anthracite is more environmentally favorable than that in bituminous coal.
Abstract: The dehydrated Huolinguole lignite (HL) together with the extracts and the extraction residues obtained from supercritical ethanolysis of HL were analyzed by Fourier transform infrared spectrometry (FT-IR). The extracts were further analyzed by gas chromatography/mass spectrometry. The mechanism for supercritical ethanolysis of HL was discussed according to the analytical results. The supercritical ethanolysis of HL includes alkyl substitution and cleavage of ether bonds. The cleavage of ether bonds is mainly occurring in aliphatic ether bonds.
Abstract: Experiments on chemical looping combustion were conducted in a 1 kWth interconnected fluidized bed reactor using a natural hematite as oxygen carrier and Shenhua bituminous coal and Huaibei anthracite as fuel. An evaluation of hematite oxygen carrier decorated with NiO by mechanical mixing and impregnation methods was also performed. The results indicate that coal gasification rate is a time limiting step in chemical looping combustion of coal and the coal type has a great impact on CO2 capture efficiency. When fuel reactor temperature is 970 ℃ and hematite as oxygen carrier, CO2 capture efficiency for Shenhua bituminous coal is 81.7%, whereas the one for Huaibei anthracite is 65%. Hematite shows stable reactivity in a process of long-term operation and it should be a good candidate of oxygen carrier for chemical looping combustion of coal. It is an effective way to improve the reactivity of hematite oxygen carrier as well as CO2 capture efficiency by mechanical mixing with NiO/Al2O3 oxygen carrier. Impregnating NiO on hematite shows a negative effect of reaction performance between product of coal gasification and oxygen carrier due to the poor microstructure after calcination. Further investigations on method and process of impregnation should be done.
Abstract: Deposition behavior of coal and rice straw co-combustion is studied in different reaction time at 1 200 ℃. The deposition was analyzed by scanning electron microscopy and spectroscopy, X-ray diffraction and electron microprobe in the 18 kW drop tube furnace. The results show that Si, Al and Ca of deposition get a little change in different mixing ratio or different reaction time. The K-feldspar stickability of surface make it easier to deposit, and K-feldspar makes the deposits structure more stable. Aluminum silicate and Fe in the deposition process plays an important role.
Abstract: The transformation behavior of mineral matter in two coals (Xiaolongtan lignite and Fugu bitumite) with a high Si/Al ratio in coal ash was investigated under reducing atmosphere at high temperature by XRD and FT-IR. Furthermore, the theoretical changes of the main mineral composition at high temperatures were calculated using the thermodynamic software package FACT sage. It is found that the transformation behavior of mineral matter in the two high Si/Al ratio coals is different. The content of CaO has different effects on the transformation behavior of mineral. The major mineral matter formed at high temperature for the coal ash with high Ca content may be anorthite or gehlenite that maybe includes Mg, Na and K elements, while the major mineral formed for the coal ash with low Ca content maybe contains a large amount of aluminosilicate and a little anorthite. Iron oxide has little effect on the components of mineral matter in coal ash. The content of quartz decreases with increasing temperature. The forming of eutectic mixture leads to the decrease of the fusion temperature of coal ash, and the increase of the amorphous phase as well. The results of FACT sage calculation are consistent with the analysis of XRD and FT-IR.
Abstract: The appropriate ashing temperature, ashing time and ash characteristics of co-firing of platanewood and bitumite were studied by SEM/EDS analysis, X-ray diffraction and ash fusion experiment. It was found that the appropriate ashing time was 2 h. The ashing temperature should be adopted at 650, 700 and 800 ℃ according to the different proportions of platanewood proportion. With the increasing of platanewood proportion, the SiO2 and Al2O3 contents decrease, but the contents of K2O, CaO and MgO are the reverse, the Na2O and Fe2O3 contents are at a low level which have no obvious trendy change. Anorthite appears in the ash with the 30% mixture ratio. The albite appears and the mullite disappears with the 50% mixture ratio. The crystalline phase intensity reduces with the increasing of ashing temperature. The aluminosilicate formed by alkali oxides with high content in the platanewood ash and silicon, aluminum oxide is the immediate cause of a low ash fusion point.
Abstract: The gasification kinetic characteristics of petroleum coke treated in micromave was studied at 1 000~1 150 ℃ with a water vapor fraction range of 30%~100% by using a thermogravimetric analyzer, and the experimental data was fitted with four kinetic models. The results show that the gasification rate of petroleum coke treated in microwave increases with the decrease of microwave irradiation time, power and temperature. At 1 100 ℃, the steam gasification rate of petroleum coke-treated increases with coke conversion initially, and then decreases after reaching a maximum value when the coke conversion is about 20%, which does not change with the microwave treatment conditions and the water vapor fraction. However, the maximum rate occurs earlier with the increase of gasification temperature. The steam gasification reaction rate of petroleum coke by microwave treatment at different temperatures can be well fitted with the normal distribution function model, which has the correlation coefficients above 0.97.
Abstract: The chemical looping gasification (CLG) of biomass with natural hematite (Fe2O3) as oxygen carrier was experimentally investigated in a bubbling fluidized bed reactor using argon as fluidizing gas. The effects of reaction temperature, resistance time, and the presence of oxygen carrier on the syngas composition, gas yield, carbon conversion, and gasification efficiency were examined. The experimental results show that the natural hematite can be used as oxygen carrier in CLG of biomass. The concentration of CO and H2 increases slightly, while that of CO2 and CH4 declines slightly with the increasing of temperature during biomass gasification. In addition, the concentration of H2, CO, and CH4 in the syngas slowly increases with the reaction time, but CO2 concentration shows an opposite trend. The presence of oxygen carrier can significantly increase the gas yield and carbon conversion. The analysis by Scanning electron microscopy-Energy Disperse Spectroscopy (SEM-EDS) shows that the iron ore oxygen carrier is obviously sintered when the reaction temperature is greater than 850 ℃. However, the composition of element on the particle surface changes little during the reaction.
Abstract: The characteristics of biomass gasification with oxygen-steam mixtures in a fluidized bed are studied in this paper. The effects of feedstock, equivalence ratio (ER), steam to biomass ratio (S/B), gasification temperature, secondary oxygen supply and bed materials on gasification performance were investigated. The results showed that higher C and H content of feedstock was more favorable for higher H2 and CO content and lower tar content of fuel gas. The H2 content increased with gasification temperature and reached its maximum at ER=0.27 and S/B=0.6. Higher gasification temperature (>840 ℃) also contributed to higher CO content. The introduction of secondary flow upper the feedstock inlet with a second flow ratio of 15% improved the gas quality significantly, and more tar was reduced as the secondary flow inlet move upward the gasifier. Dolomite and limestone performed better than olivine on cracking tar and increasing H2 content, but resulted in higher ash content.
Abstract: A series of experiments of microalgae pyrolysis using microwave were carried out. The influences of different additives such as activated carbon, H3PO4, NaOH, MgCl2, MgO on microalgae pyrolysis were examined. The weight loss during pyrolysis of microalgae with different microwave powers (200, 600, and 900 W) were studied. The result shows that there are four stages in microalgae pyrolysis: dehydration, drying, rapid pyrolysis and slow pyrolysis. All the additives improve the yield of solid product significantly, but reduce the gaseous yield; and have no remarkable influence on the liquid yield. However, H3PO4 and MgCl2 raise the liquid yield, NaOH is opposite. The corresponding activation energy of microalgae rapid pyrolysis was obtained by Flynn-Wall-Ozawa method (FWO), and the value generally increases with the deepening of the reaction.
Abstract: Select ZnCl2 as catalyst for hydrogenation and liquefaction in the autoclave, study polarity and hydrogen of solvent for the liquefaction yield of lignin sulfonate and products by GC-MS and infrared spectroscopy. Yield analysis shows, solvent's polar favor for lignin conversion, hydrogen donor solvent can improve the yield of light distillate, the highest conversion of lignin under water and the highest yield of light distillate under the methanol conditions, increased 2.0-times and 1.9-times compare to lowest yield of 1,4-dioxane solvent;GC-MS analysis showed, medium polarity solvents was well to neutral fraction stability, hydrogen donor solvent tetralin can release of hydrogen to binding and stability the radical intermediates,Ethanol have the neutral product of the relative content of 48.76% relative to the minimum 2.2 times the water solvent systems. Infrared analysis showed, in response to alcohol solvent, tar products of hydroxyl peak intensity increased.
Abstract: Cellulose was degraded in concentrated ZnCl2 solution which acted as a solvent and catalyst under microwave irradiation. Cellulose was directly converted into two main furans, 5-hydroxymethyl furfural (5-HMF) and 1-(furan-2-yl)-2-hydroxyethanone. Factors affecting the mol yields of these two compounds were investigated at different temperatures, reaction times, concentrations of ZnCl2, cellulose contents, and microwave powers. For 1 g cellulose reacted with 140 mL 69% ZnCl2 solution, the mol yields of 5-HMF reached to 19.4% under the microwave power of 500 W and 1-(furan-2-yl)-2-hydroxyethanone reached to 12.0% under the microwave power of 600 W at 135 ℃ within 5 min.
Abstract: Ca/Al solid basic catalysts were prepared by co-precipitation method and used in the synthesis of biodiesel from rapeseed oil; the effect of preparation conditions such as precipitant selection, mole ratio of calcium to aluminum, precipitation temperature, pH value, aging temperature and time, and calcination temperature on their catalytic activity were investigated. Through orthogonal tests, the optimal conditions to prepare catalyst precursor are obtained as Ca/Al = 3, NaOH as precipitant, precipitation temperature of 60 ℃, pH value of 10, and aging at 90 ℃ for 18 h. Under the optimal conditions, the catalyst precursor obtained is in the form of Ca4Al2O6(NO3)2·10H2O crystal. After calcination at 300 ℃ for 2 h in N2 atmosphere, Ca/Al mixed oxide is then highly dispersed on the catalyst surface with a pH value of above 26.5. The catalyst exhibits excellent activity in transesterification of rapeseed oil with methanol; the conversion of rapeseed oil and selectivity to fatty acid methyl ester reach 95% and 95.9%, respectively.
Abstract: MgFe-hydrotalcites (MgFe-LDH) were prepared by using improved urea method and used as the catalysts in the synthesis of biodiesel oil from chlorella protothecoides oil. The hydrotalcites were characterized by XRD, FT-IR, SEM as well as Fourier self-deconvolution and band curve-fitting analyses; the effects of pH value, Mg/Fe mol ratio, temperature and time to prepare the hydrotalcites on their properties and catalytic performances were investigated. The results showed that the MgFe-LDH with Mg/Fe mol ratio of 3 and 4 (Mg3Fe and Mg4Fe), prepared at 110 ℃ and pH value of 9.5 for 10 h exhibits high symmetrical crystalline structure. The brucite-like layer of Mg3Fe and Mg4Fe hydrotalcites are stable under calcination for a completely decomposition. compared with the Mg2Fe hydrotalcite with Mg/Fe mol ratio of 2, Mg3Fe and Mg4Fe upon calcination exhibit higher crystallinity and more active sites and higher catalytic activity. For the synthesis of biodiesel oil from chlorella protothecoides oil over the Mg3Fe catalyst, with methanol/oil molar ratio of 6 in the feed, the biodiesel oil yield reaches 87% after reaction 1.5 h; the catalyst can be reused for three times without serious deactivation.
Abstract: CH4-CO2 reforming was carried out over a Ni-CaO-ZrO2 catalyst prepared by co-precipitation. The influence of reaction conditions like temperature, space velocity and feed component on CH4-CO2 reforming and coking properties was studied. Thermodynamic calculation as well as experimental measurement indicated that the reaction conditions play an important role in the behaviors of reforming and coke deposition. Higher activity and stability are observed under higher temperature due to the enhancement of both CH4 decomposition and elimination of carbon species formed at such condition. At higher space velocity, both the conversion of CH4 and the rate of carbon elimination are decreased, resulting in an increase of carbon deposition. The component of feed gases also has a significant impact on the amount of carbon deposited; a higher CO2/CH4 molar ratio is favored in suppressing coking during the reforming reaction.
Abstract: Cu-Mn, Cu-Zn and Cu-Mn-Zn supported on zeolite Y were tested for the synthesis of dimethyl ether (DME) directly from synthesis gas in a fixed-bed reactor, and characterized by means of H2-TPR, XRD and TPD. The results showed that Zn was beneficial to the reducibility and H2 chemiadsorption of the catalysts, but decreased the ability of CO chemiadsorption; Mn was beneficial to CO adsorption, but decreased the reducibility and ability of H2 chemisorption. Thus, the synergic effects of Zn and Mn in Cu-Mn-Zn/zeolite-Y catalyst grew more and stronger adsorption sites of H2 and CO, made a favorable catalyst for direct DME synthesis. Consequently, the Cu-Mn-Zn/zeolite-Y catalyst exhibited the best catalytic performance for direct synthesis of DME was duo to the synergic effects of Zn and Mn to the proper adsorption ability of H2 and CO.
Abstract: In-situ covering technology was used to prepare the Y/ASA composite material in which Y zeolite was covered around with amorphous silica-alumina (ASA). Two kinds of supported Ni-W catalysts for hydrocracking of decane were prepared using Y/ASA and Y-ASA as supports, respectively. Y-ASA was a kind of mechanical mixture of industrial Y zeolite and ASA. The supports and catalysts were characterized by X-ray powder diffraction, scanning electron microscopy, infrared spectroscopy of pyridine adsorption and N2 adsorption-desorption. The results showed that, while there were less total acid sites on Y/ASA and Ni-W/Y/ASA, there were more strong acid sites.The ratios of strong acid sites to weak acid sites of Y/ASA and Ni-W/Y/ASA were higher than those of Y-ASA and Ni-W/Y-ASA. The average pore diameter, mesopore surface area and pore volume of Y/ASA and Ni-W/Y/ASA were larger than those of the comparative samples, respectively. The hydrocracking of decane over the Ni-W/Y/ASA catalyst revealed that the conversion and yield of middle-component(C5~9) were improved by 7.6 % and 12.4 %, respectively, compared with that over Ni-W/Y-ASA catalyst.
Abstract: Supported Fe(2/3)xNi1-xSO4-P2O5/γ-Al2O3 catalysts were prepared through impregnation and used in the oligomerization of mixed C4 olefins; the effect of preparation parameters and reaction conditions on their oligomerization performance was investigated in a high pressure fixed-bed microreactor. The results demonstrated that under 3.0 MPa, 100 ℃ and a volume space velocity of 2 h-1, the conversion of olefins and selectivity to dimer reach 50.7% and 52.2%, respectively, over the catalyst with a preferable Fe loading of 0.7 mmol/g(γ-Al2O3)and Fe/Ni atomic ratio of 2. In addition, it was found that the interaction between γ-Al2O3 and SO42-plays an important role in the efficiency of active sites.
Abstract: The nickel-based ZnO adsorbents were prepared by mix-kneading method using different supports with metal-oxide, clay and zeolite. The physiochemical properties of the catalysts were characterized using FT-IR. Then the chemical adsorption performance of thiophene on the adsorbents was studied in a fixed bed stainless steel tubular micro-reactor. The results show that the desulfurization performance varies for different adsorbents. The desulfurization performance of adsorbents with clay supports is higher than that of metal-oxide supports. The desulfurization performance decreases in order of clay-sorb > diatomite-sorb > Al-sorb > Ti-sorb. The sulfur removal rate increases with the total Lewis acidity of the adsorbent. The desulfurization performance decreases in the order of MCM-22-sorb > HY-sorb ≥ Hβ-sorb > H-mordenite-sorb > HZSM-5-sorb. By comparing the pore structure of zeolite supports, it shows that the effective pore size of zeolite supports is the key factor to influence the desulfurization activity.
Abstract: In order to meet more and more strict policy of environment protection, an investigation into the oxidative desulfurization (ODS) process for gasoline was carried out to use an oxidant (H2O2) over the D072 resin catalyst . The reaction conditions including the temperature, the amounts of oxidant and the reaction time were studied and discussed. The experimental results show that a maximum sulfur compounds removal of 75% is obtained in the presence of H2O2 with an O/S molar ratio of 17 at room temperature (RT) and atmospheric pressure, which can make a simple and cheap process. The possible mechanism was also disscussed in the study.
Abstract: The catalysts of perovskite-type complex oxide loaded on HZSM-5 zeolite were synthesized. The catalysts were characterized by XRD, SEM, XPS and H2-TPR, and their performance for combusting soot was evaluated in a fixed micro-reactor. The results show that when B-site ion was consisted of various metals, the catalytic performance was improved, the soot combustion temperature decrease, and the selectivity forming CO2 increased. The performance of catalysts was affected by the species and component of B-site ion. The selectivity forming CO2 increased and the temperature of soot combustion reduced when Cu and Co ion was in B-site, respectively. The temperature of soot combustion and selectivity forming CO2 was improved with changing the mole ratio of Fe/Mn. Among them, LaMn0.2Fe0.7Cu0.1O3/HZSM-5 catalyst has better performance with lower combustion temperature of Tig, Tm and Tf at 236.6, 419.0 and 458.7 ℃, respectively, and higher selectivity forming CO2 of 88.3%。
Abstract: Kinetics for photocatalytic degradation of quinoline over nanosized titanium dioxide prepared by sol-gel method was investigated. On the basis of Langmuir-Hinshelwood model, a kinetic equation for the quinoline degradation over TiO2 was proposed, which can be described as r = 0.296kct/(1+0.296ct), where lnk =-0.411 1 lnc0+2.278.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
