Abstract: The sulfur-containing gases evolved from three kinds of coal and their oxidized samples by air and HNO3 were investigated by atmospheric pressure-temperature programmed reduction (AP-TPR) with H2. The results show that although the amount of organic sulfur did not change remarkably, the H2S evolved from the oxidized sample decreased, COS and SO2 evolved increased significantly. This indicated that the aliphatic sulphides were selectively oxidized to sulphoxide and sulphone. Different with the previous study, it was found that the formation of CS2, arising from the reaction of H2S and COS, has a close relationship with FeS. The amount of CS2 in air-oxidized coal is similar with that from raw coal, but less than that from HNO3-oxidized sample. The ratio of (COS+SO2)／H2S was suggested to stand for the oxidation extent. The higher this ratio, the more severer the oxidation. The results showed that the (COS+SO2)/H2S ratio decreased with the coal rank and the amount of thiophenes. For the same coal, the oxidation by nitric acid is deeper than that by air.
Abstract: Based on the analysis of 8 samples of raw and cleaned coal collected from 4 coal-washing plants and the results of simulated coal cleaning experiments for 2 raw coals, removability of ash, sulfur and 20 hazardous trace elements in these samples during coal cleaning were studied. Combined with the previous works, cleaning potential of the hazardous elements were systematically discussed. The results suggested that physical coal cleaning was not only a mature technology as applied to the removal of ash and sulfur, but also effective in reducing the concentration of hazardous trace elements in varying degrees. It was anticipated that more than 50% of ash and the hazardous elements As, Co, Cr, Cu, Hg, Mn and more than 30% of sulfur in most coal would be routinely removed by physical coal cleaning procedures, however, the removability of other hazardous elements Ba, Be, Cd, Cl, Mo, Ni, P, Pb, Sb, Se, Th, U, V and Zn displayed relatively lower or a wide range of variation.
Abstract: The coking characteristics of endothermic hydrocarbon fuel S-1 on Ni-Cr alloy was studied in a laboratory-scale continuous flow reactor system. The carburation on alloy was proved by EDX analysis. The composition of cokes was determined by element analysis (EA), which showed that the ratio of hydrogen and carbon of the coke decreases soon with the extending of reaction time. Surface morphology of coke was determined by means of scanning electron microscopy (SEM) after heat treatment at the temperature from 700 ℃ to 1 200 ℃ with heating rate of 20 ℃/min by Differential scanning calorimetry (DSC). The results show that temperature has an important effect on the structure of cokes. The analysis results of soluble coke show that intermediate coking product consists of aromatic compound and paraffin.
Abstract: The characteristics of biomass air-steam gasification in a fluidized bed were analyzed in this paper through a series of experiments. The effects of reactor temperature (700℃～900℃), steam to biomass ratio (0～4.04), equivalence ratio (0.19～0.27) and biomass particle size (0.2mm～0.9mm) on gas composition, gas yield, steam decomposition, lower heat value (LHV) of fuel gas were investigated. Under the experimental conditions examined, the fuel gas yield ranges between 1.43 Nm3/kg and 2.57 Nm3/kg biomass and the LHV of fuel gas ranges between 6741kJ/m3 and 9143 kJ/m3. The results show that higher temperature contributes to more hydrogen production, but lower LHV. Compared with biomass air gasification, the introduction of steam improves gas quality. But excessive steam will lower gasification temperature and degrade fuel gas quality. The biomass particle size also has influence on gas composition and gas yield. The smaller particle yields more CH4 and CO, but less CO2.
Abstract: Thermogravimetric analysis was used to study the pyrolysis characteristics of two biomass samples, corn straw and rice straw, at different heating rates of 5 K/min, 10 K/min, 20K/min, 40 K/min in a stream of N2. Four methods: Coats-Redfern，Doyle，Kissinger and DAEM, were used to determine the kinetic parameters, including reaction order, frequency factor and activation energies. The results indicated that the kinetic parameters were different with different methods. The pyrolysis process can be described by first-order global model for both corn straw and rice straw and their activation energy was 68.8 kJ/mol and 70.0 kJ/mol (weight loss from about 5 w% to 80 w%) at the heating rate of 10 K/min, respectively, with the method of Coats-Redfern. Almost the same results were obtained with Doyle and DAEM model. Pyrolysis of the two biomass samples was a complicated reaction and their activation energies varied with increasing weight loss. The model of Doyle and DAEM was efficient method to provide more information of pyrolysis of the biomass samples.
Abstract: According to the experimental result on cellulose pyrolysis in heat radiation reactor, a mechanism of cellulose pyrolysis was studied on primary products formation, such as levoglucosan, glycolaldehyde and acetol etc. In the case of rapid devolatilization and following chill, the formation of glycolaldehyde and acetol appeared to compete with that of levoglucosan. Then, a kinetic model based on competitive reaction was proposed to simulate the formation of glycolaldehyde and acetol. It was concluded that formation of glycolaldehyde was similar with that of acetol in kinetic behavior, showing that there existed two similar initial formation reactions. During pyrolysis process, cellulose underwent decomposition through heterolytic or homolytic fission of some reaction precursors, which could be called as active cellulose. Anhydrosugars, including levoglucosan and its isomeric compounds, were formed by heterolytic fission of glucosidic bond under transglycosylation reaction. While small molecular compounds, such as glycolaldehyde, acetol and CO, were formed by acetal open-loop and following C-C bond rupture. On the basis of Brodio-shafizadeh model, a mechanism model was proposed to simulate levoglucosan formation at high temperature of thermal radiation source. The calculation result was consonant well with experimental value.
Abstract: In order to elaborate NO emission characteristics of waste combusted in fluidized bed, N→NO of six representative single-component wastes with bed temperature and excess air was studied in a Ф150 mm fluidized bed. The results show that paper and wood have the highest conversion while rubber and plastics have the lowest conversion of N→NO. N→NO of fabric, paper, kitchen residue, wood, plastics has intermediate temperature formation behavior, it generally maximizes during 800 ℃ and 850 ℃, then it will be stable with increasing temperature. N→NO will increase with increasing temperature because coal and rubber's fuel-nitrogen has stable chemical structure. N→NO of mixed waste material is generally less than linear superposition value of single-component waste because of volatile flux's interaction and relatively lower flame temperature; small a mount of water did not affect obviously N→NO, even it can accelerate NO emission, but excessive water will inhibit NO formation behavior.
Abstract: Effect of hydrogen and oxygen on H2S removal by ZnO desulfurizer were investigated by thermogravimetric analysis. The microkinetics of desulfurization in the presence of hydrogen and oxygen were also studied. Experiments were carried out with spherical grain of 100mesh～120mesh, at temperatures from 200 ℃ to 320 ℃. The results show that hydrogen could accelerate the reaction in the range of 0%～40%. Oxygen had complicated influence on H2S removal because of the deposition of sulfur. The kinetic behaviors of desulfurization could be described by improved shrinking core model. The activation energies of reaction and diffusion were 14.96 kJ/mol and 46.77 kJ/mol, respectively.
Abstract: Experimental research has been done on a twin-fluid nozzle using FAM laser particle distribution analyzer. Factors affecting spray angle and distributions of Sauter mean diameter (SMD) have been analyzed. It is found that the most important parameters are air liquid ratio and slurry concentration. The SMD will be decreased when decreasing slurry concentration and increasing air liquid ratio. Fine atomization can be obtained for air to liquid ratio in the range from 0.09 to 0.3. The SMD changes from 20 micron to 100 micron respectively. The correlation of SMD has been obtained considering slurry concentration and air liquid ratio. It is found that the spray angles are similar for three nozzles. They are about 20 to 25 degree. The spray angle will be decreased when increasing air to liquid ratio but almost unchanged when changing slurry concentration.
Abstract: The slurriability and dosage of some different structure dispersants are studied in the pitch-water slurry(PWS) of Erlian deasphalting pitch and the effect of dispersant adding mode is discussed. The opinion on PWS dispersant is put out that they are consistent when the structure of dispersant and pitch is similar. At the same time, the conception of excellent mol dosage is brought out. The experiment results show that the best PWS dispersant is the pitch sulfonate. It accords with the HLB requirement of PWS and is a good dispersant. Ascertaining the excellent mol dosage can help confirm the best industry dosage. The PWS of high consistence, low viscidity and good stability is produced by the wet crushing and multi adding mode.
Abstract: In the study of the application of high-density fuel HDF-1, the compatibility of rubbers used in the system with fuel HDF-1 is one of important issues because it directly affects the storage, transportation and use of fuel HDF-1. This paper reports the effects of fuel HDF-1 on the rubbers such as nitrile rubber 4170, nitrile rubber 5171, fluorinated silicone rubber G402 and container rubber at room temperature or 70 ℃ and comparison of the results with No.3 jet fuel (RP-3).The rubbers were characterized by FTIR. The results show that fluorinated silicone rubber G402 and container rubber are compatible with fuel HDF-1 and fuel RP-3. Fuel HDF-1 is less compatible with nitrile rubber 5171 than fuel RP-3, and fuel HDF-1 is least compatible with nitrile rubber 4170. Therefore, nitrile rubber 4170 and nitrile rubber 5171 are not suitable for the storage and transportation of fuel HDF-1, the rubbers used in the fuel RP-3 system cannot be directly used in the fuel HDF-1 system.
Abstract: Hydrogen production by partial oxidation steam reforming of methanol over a Cu/ZnO/Al2O3 catalyst has been paid more and more attention. In order to optimize the operation conditions and improve the catalysts used in the methanol partial oxidation steam reform reaction, the mechanisms of the reaction in a tubular reactor are analyzed. The heat effects, reaction equilibrium constants for different reactions in this system and equilibrium compositions at corresponding reaction temperatures are investigated. By these analyses, thermodynamic competitive abilities for these reactions may be understood. The kinetic expressions for partial oxidation of methanol, steam reforming of methanol, decomposition of methanol and water gas shift reaction are evaluated. These kinetics can be used in the design of the reactor and the optimum of the operation conditions. From the basic concept of the effectiveness factors, the intraparticle diffusion limitations were taken into account. The effectiveness factor for each reaction along the bed length is calculated. It describes the difference between the real reaction rate inside the catalyst pellets and the intrinsic reaction rate in the bulk phase along the reactor bed length in the reaction temperature range.
Abstract: The coagulation of the small crystal beta zeolite colloidal system in filtering system with the present of coagulating material NS and the mechanics of coagulation were studied. The colloidal structure of beta zeolite particles in the filtering system, by means of analyzing its existence state, is recovered. Meanwhile, the variation of Zeta electric potential, while the contra-ion extrudes Stern electric double layer, is analyzed, and the reason of coagulation is well explained. It is found that the small crystal beta zeolite can coagulate at the room temperature when the ratio of NS to beta zeolite (net weigh) is not less than 30%, which can increase the filtering efficiency of little crystal beta zeolite greatly. Relative crystallinity of beta zeolite coagulated by NS decreases a little, and the same time, the Na2O percentage content of beta zeolite drops with wide range. Experimental results provided by activity test on a light oil micro-test reaction apparatus state that beta zeolite coagulated by NS is also an excellent activity additive of FCC catalyst.
Abstract: SAPO-11 zeolites were hydrothermally synthesized with n-dipropylamine(DPA) as template. The effects of nature of silica sources, ratios of raw materials and crystallization parameters such as crystallization temperature，time and pH value, on SAPO-11 crystallization were systematically discussed. Of interest is that the nature of silicon feed was justified to be one of key factors for synthesis of SAPO-11 zeolites. The selective tests of Si resources proved that acidic silica gel is a suitable feed, which could provide active silica intermediates just accompanying by slow formation of SAPO-11 precursor. It was shown that highly crystalline SAPO-11 zeolites could be produced with material ratios of SiO2/Al2O3=0～0.7，DPA/P2O5=0.8～1.8 and under contiguously neutral media environment (pH=5.8～7.8). In addition, it was found that SAPO-11 zeolite appeared after 4 h and completely crystallized after 24 h, following by transformation between SAPO-11 and 31 with time on.
Abstract: The processes of adsorption and oxidation of 1-butanol on Pt electrode and Pt electrodes modified with Sb and S (Pt/Sbad and Pt/Sad) were studied by cyclic voltammetry and electrochemical quartz crystal microbalance (EQCM). The results demonstrated that the oxidation of 1-butanol depends strongly on the oxidation states of electrode surface Sb adatoms on Pt surface can adsorb oxygen at relatively low potentials, and exhibit catalytic effects for 1-butanol oxidation. In comparison with the case of Pt electrode, the oxidation peak potential of 1-butanol on Pt surface modified with Sb was negatively shifted about 330 mV and the peak current was doubly increased. On a contrary, the oxidation of S adatoms consumes oxygen species of Pt electrode surface. As a consequence, the oxidation of 1-butanol was inhibited by the presence of Sad. The EQCM studies provided quantitative results of surface mass changes during 1-butanol oxidation, and have thrown new light on elucidating different effects of adatoms Sbad and Sad on Pt electrode towards 1-butanol oxidation.
Abstract: Carbon nanotubes(CNTs) were produced by pyrolysis of methane in DC arc argon plasma in the present study. TEM, ICP-CAS, TGA were used as analytical tools. Experimental results show that the CNTs grew on the chamber wall with multiwalled structure and various shapes. Another advantage of this method is that it can produce hydrogen simultaneously.
Abstract: A suitable system and the best condition were determined for sulfur removal from coal by electrolysis through testing, and the effect of electrolytic conditions on desulfurization rate was studied. At the same time, the influence of electrolysis desulfurization on the structure of coal was inquired into. The results showed that the effect of desulfurization was the best in sodium bromide electrolytic system, the best desulfurization condition was ［NaBr］=1.5 mol/L, I=0.7A, T=343 K, t=4 h and the highest desulfurization rate reached 89%. We found that with increasing electrolytic conditions, desulfurization rate increased at first, and then kept constant. The analysis of IR spectrum showed that the structure of coal wasn't destroyed.
Abstract: Desulphurizer is one of the key factors in the field of desulphurization technology. In this paper, the influence of several additives on the desulphurization effect of calcium-based compounds and the mechanism were analyzed based on a lot of experiments. Different kinds of sulfur-fixing agents based on CaCO3 were prepared by inputing some single additive, some mixed additives and reformed by some chemical solutions. The desulphurization rate of these agents was studied with ZCS-1 intelligent sulphur determination. Some highly efficient agents and CaCO3 were calcined, and their physical characteristic were studied with PoreMaster-60 mercury porosimeter. Some reformed agents by some chemical solution after being added certain additives had better results at high temperature. The sulfur-fixing efficiency of the best one could reach as high as 50% (Ca/S=1.5) at 1 100 ℃. Its physical and sintered characteristic at high temperature were improved. After reformed with aliphatic acid and being added some additives, the porosity of CaCO3 increases from 15.57% to 34.93% while its surface area increases from 14.52 m2/g to 19.94 m2/g.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
