Abstract: The phosphorus content in Chinese coals was studied based on 1117 coal samples from Chinese Coal Resource Database and new sampling coals. The results show that the weighted mean content of phosphorus in Chinese coals is 224×10-6, about 90% of the phosphorus content of Chinese coal below 500×10-6 and belong to lower or super lower content, and the phosphorus content in southern China is higher than in northern China. The distribution of phosphorus in Chinese coal from different coal-accumulated area, different geological ages, and different classes of coals was discussed. The results show that the phosphorus content of coal in Triassic period from southern China (Jiangxi, Hunan, Sichuan, Yunan and Fujian provinces) is the highest. The relativities between the phosphorus content and other factors were analyzed. The results show that the phosphorus content of Chinese coal has no significant correlation with sulfur, forms of sulfur, ash and ash component, the correlation between phosphorus and strontium, fluorine are obviously higher than other elements in Chinese coals.
Abstract: Comparative column leaching experiments were carried out on a coal sample collected from Moxinpo Mine in Chongqing, Southwest China. Different acid solutions were used to investigate the leaching behavior and potential environmental effects of bromine in coal. The leaching rate and maximum leached concentration of bromine were calculated based on the concentration of bromine in different resulting leachates measured by inductively coupled plasma mass spectrometry. The results show that the modes of occurrence and locations of bromine in coal, time, and pH value played an important role in controlling the leaching behavior of bromine in coal. At 120h, the maximum leached concentration and total leaching rate of bromine in coal increased with an increase in the acidity of the leaching solution. The amount of bromine released from coal leached at pH of 2 comprised about 80.65% of its total leached amount for 40h, whereas it was 89.42% at pH of 4 for 50h. When leached by an acidic solution, the bromine occurring in carbonate and Fe－Mn oxides located on the surface of coal particles may be released first, followed by the bromine in water-soluble and exchangeable forms in the interior of the coal matrix. The experiment shows that the bromine in coal may be leached out by acidic rain and enters the surrounding soil and surface water, resulting in the enrichment of bromine in the environment.
Abstract: Sink-float centrifugation was used to get the vitrinite (SDV) from Shendong raw coal. The SDV was studied by 13C-CP/MAS NMR to reveal the structure characteristics of carbon atom and 12 structure parameters. The results indicate that naphthalene with condensation degrees of 2 is the main form of aromatic carbon in SDV. Benzene ring and aromatic ring with heteroatom is another existing form. Based on structure parameters and elemental analysis, macromolecular structure model of SDV is constructed. 13C chemical shift of SDV macromolecular structure is calculated by commercial software of ACD/CNMR predictor. According to the calculation results, macromolecular structure model of SDV is corrected, and finally the calculated chemical shift diagram of model can tally well with the experimental result.
Abstract: Pyrolytic characteristics of acid hydrolysis residue from corncob (residue in short), were studied using thermal analyzer, tube furnace, gas chromatogram (GC), gas chromatogram-mass spectrometry (GC-MS) and scanning electronic microscopy (SEM). The thermogravimetric analysis shows that pyrolysis of the residue mainly occurs in 280℃~450℃ with only one obvious mass loss peak. The tube furnace test indicates that with increase of temperature gas yield increases greatly, while char and tar yield show decreasing trend. Among the gaseous products, with increase in temperature, H2 and CH4 increase, CO2 decreases; compared with corncob, the residue releases more CO, H2 and CH4, and less CO2 during pyrolysis. The main compounds identified through GC-MS are phenol and polycyclic aromatic hydrocarbons. SEM images show that char prepared at higher temperature is more uniformly crystallized.
Abstract: Nannochloropsis sp. was pyrolyzed directly or with H-ZSM-5 as catalyst under nitrogen atmosphere to produce bio-oil. The influence of pyrolysis temperature on the product distribution in the pyrolytic oil was investigated within the range of 573K～773K. Compared with the pyrolysis of lignocellulosic biomass, the pyrolysis of Nannochloropsis sp. can be performed at relatively lower temperature and with higher oil yield. H-ZSM-5 is effective for the removal of various polar functional groups as well as for the aromatization; and the bio-oil obtained with H-ZSM-5 catalyst contains more aromatic compounds and fewer polar species than that from direct pyrolysis. The heating values of the bio-oil from Nannochloropsis sp. is higher than that from lignocellulosic biomass, and thus the former is more suitable to be upgraded to practical fuel.
Abstract: The pyrolysis characteristics and kinetics of fir sawdust were investigated via thermo gravimetric analysis at different heating rates. The distributed activation energy model (DAEM) was used to study the pyrolysis kinetics. The influence of temperature on organic structure of semi-char was analyzed by FT-IR. The pyrolysis of the samples was divided into four stages: extraction of water, transition, main pyrolysis and charring. As a function of conversion rate, the pyrolysis activation energies are between 103kJ/mol and 179kJ/mol. When the temperature is below 200℃, the function groups remain unchanged but a weaker intensity. With the increase of final temperature, the contained organic function groups in semi-char decrease greatly. When the temperature is above 500℃, the types of function groups remain unchanged and the main pyrolysis reaction process is completed.
Abstract: The toluene cracking experiments were carried out in an eutectic salt reactor. Catalytic effects of NN salt (8.3%Na2CO3+91.7%NaOH) and NK salt (71%Na2CO3+29%K2CO3) on the toluene cracking rate, gas product yield and benzene yield were investigated. The results show that the eutectic salts have obvious catalyses on the toluene cracking. When cracking at 800℃ with NK salt and NN salt, the toluene cracking rates are increased by 27% and 46%, respectively, compared with thermal cracking. And the benzene yield is greatly reduced. When cracking with NN salt at a temperature higher than 750℃, H2 in gas product is mainly from the reaction between NN slat and the cracking tar.
Abstract: Colloidal stability variation of Dagang atmosphere residue (DG-AR) during thermal reaction under nitrogen or hydrogen was comparatively investigated. It was found that the colloidal stability of DG-AR samples decreases sharply along with the thermal reaction until coke is formed, and then the deterioration of the colloid stability is slowed down. At the aspect of the composition and characteristics of residue fractions, it was found that with the proceeding of the thermal reaction, the content of asphaltenes reaches its maximum at the end of coke induction period; the content of saturates and light aromatics fraction increases, while the content of heavy aromatics, light resins, middle resins, or heavy resins decreases. This trend is more prominent for the thermal reaction under nitrogen. The mean dipole moments and mean relative molecular weight of the residue fractions were measured, which suggested that as the thermal reaction is going on, the mean relative molecular weight and the mean dipole moments of maltene fractions decrease, while those of asphaltenes have their maximum values. This variation is consistent to that for the colloidal stability during the thermal reaction. The dipole moment variation of asphaltenes showed that asphaltenes having more polarity tend to be associated and transformed into coke. Furthermore, the catalyst and hydrogen is able to restrain asphaltenes from condensation and coke formation.
Abstract: Acidic ionic liquid N-carboxymethylpyridine hydrosulphate (\[CH2COOHPy\]HSO4) as the extractant and catalyst, and hydrogen peroxide as the oxidant were used to the extraction-oxidation desulphurization of model oil (dibenzothiophene dissolved in n-octane). The effects of the amounts of hydrogen peroxide and ionic liquid, reaction temperature and reaction time on the sulfur removal were investigated. The results show that when molar ratio of sulfur to H2O2 is 1∶6, volume ratio of ionic liquid to model oil is 0.6∶10, and reaction time is 40min at 50℃, the sulfur removal of model oil can reach 99.7%. The ionic liquid can be recycled 5 times without obvious decrease in the sulfur removal.
Abstract: Titanate nanotubes were synthesized hydrothermally with commercial TiO2 nanoparticles in NaOH; after calcination at 400℃, TiO2 nanotubes were obtained and used as the support to prepare manganese catalyst (MnOx/TiNT) by wet-impregnation for low temperature selective catalytic reduction of NO (SCR). The results of BET, TEM, XRD and TG measurements showed that TiO2 nanotubes exhibit well-defined TiO2 anatase phase after calcination at 400℃ and manganese particles are highly dispersed on the wall of TiO2 nanotubes. The effects of active component loading, space velocity, oxygen content, \[NH3\]/\[NO\] ratio and NO concentration on the SCR performance of MnOx/TiNT were investigated in a simulated flue gas. Under the reaction conditions of 150℃, \[NH3\]/\[NO\] of 1.2, \[O2\] of 3%, \[NO\] of 0.06%, GHSV of 23613.8h-1 and Mn loading of 5%~15%(mass ratio), NO conversion exceeds 95%. The catalyst is deactivated in the presence of H2O at 180℃, but its activity can be recovered almost completely when cutting off H2O; higher resistance to H2O is observed at higher temperature. The presence of SO2 can also deactivate the catalyst gradually; however, the catalyst exhibits better resistance toward SO2 in the presence of H2O than that without H2O. The SCR activity of MnOx/TiNT catalyst deactivated by SO2 rises gradually after cutting off H2O + SO2, but cannot be recovered to its initial level.
Abstract: High yield of ethylene glycol (EG) can be obtainedby using the catalyst with 20% Cu loading, but the short life of the catalyst blocks its industrial application. This work focuses on the cause of the deactivation behavior. SiO2 supported copper catalyst for gasphase hydrogenation of diethyl oxalate (DEO) was prepared using the ammoniaevaporation method. The catalyst was characterized by the means of X-ray diffraction (XRD), temperature-programmed reduction (TPR) and highresolution transmission electron microscopy (HRTEM). It was found that copper particles were highly dispersed on the surface of fresh catalyst in small size, and the aggregation of them was the main reason for deactivation. In addition, the results indicated that Cu0 is the main active site for the hydrogenation.
Abstract: The leaching of forsterite and serpentine was investigated and the effects of hydrochloric acid concentration and temperature were examined. Magnesium dissolution extent increases with the increase of hydrochloric acid concentration and temperature. The reactivity of forsterite is relative higher than that of serpentine. Furthermore, a modified unreacted shrinking core model was used to determine the dissolution kinetic parameters. The dissolution of forsterite is controlled by the surface reaction control. However, the serpentine dissolution is controlled by the product layer diffusion. The difference of dissolution extent and kinetics of two minerals depend on the structure and silica polymerization extent.
Abstract: A new Pd-based monolithic catalyst on cordierite honeycomb ceramics substrate without coating (Pd/cord) was prepared via electroless plating. The results of activity tests for catalytic combustion of toluene showed that Pd/cord catalysts with low Pd loading had good catalytic activities: toluene could light off at 201℃, then leap to 226℃ to burn out on Pd/cord catalyst with 0.24% Pd loading. And Pd/cord catalyst was also suitable for toluene catalytic combustion when space velocities and feed toluene concentrations varied in 6000h-1~40000h-1 and 0.5g/m3 ～8.0g/m3 respectively. During the 105h stability test of Pd/cord catalyst, the toluene conversion was kept above 97%, which indicated that this catalyst possessed good catalytic stability. The scanning electron microscope (SEM), X-ray diffraction (XRD) and temperature programmed reduction in hydrogen (H2-TPR) characterizations showed that the sizes of PdO crystal particles in Pd/cord catalyst when Pd loading was 0.24%， PdO particles were also equably distributed on the surface of cordierite substrate with no overlapping aggregation phenomenon.
Abstract: Lanthanum hexaaluminates doped with different metal ions (Fe, Co, Ni, Cu, and Mg) were prepared through co-precipitation of metal nitrates in the water phase of a Triton X-100 / n-hexanol / cyclohexane reverse microemulsion and used as the catalyst in methane combustion. Their structure and properties were characterized by X-ray powder diffraction (XRD), specific surface area (BET) and scanning electron microscope (SEM); the effects of ion dopants on their catalytic performance in methane combustion were investigated. The lanthanum hexaaluminates doped with Fe and Mn exhibit high catalytic activity and stability for methane combustion at high temperature; over the LaMnFeAl10O19-δ catalyst calcined at 1200℃, the ignition temperature (T10%) and complete combustion temperature (T90%) are 477℃ and 674℃, respectively.
Supervisor：Chinese Academy of Sciences
Sponsors by：Shanxi Institute of Coal Chemistry, Chinese Academy of Sciences Chinese Chemical Society
