Titanium silicalite-1(TS-1)films were synthesized on stainless steel plate,glass slide and monolith supports via an in-situ hydrothermal method.Characterization data showed that the formation of TS-1 films was easier ...Titanium silicalite-1(TS-1)films were synthesized on stainless steel plate,glass slide and monolith supports via an in-situ hydrothermal method.Characterization data showed that the formation of TS-1 films was easier on the porous flat support with rough surface such as monolith than on the smooth non-porous supports like glass slide and stainless steel plate.The film on the monolith had the highest uniformity and smallest size of crystals.The catalytic property of monolithsupported film was tested for epoxidation of allyl chloride(ACH)by H2O2in a fixed bed reactor.Under the condition of a methanol(solvent)/ACH(90% )/H2O2(30% )ratio of 12:1:1,a LHSV of 1.35 h-1and a temperature of 318 K,the conversion of allyl chloride and the selectivity to epichlorohydrin reached 79% and 51% ,respectively.展开更多
Dried anaerobic granular sludge （DAGS） for removing phenol （organic） and lead （inorganic） pollutants from synthetic wastewater was examined in a fixed bed system. A general rate multi-component model has been bu...Dried anaerobic granular sludge （DAGS） for removing phenol （organic） and lead （inorganic） pollutants from synthetic wastewater was examined in a fixed bed system. A general rate multi-component model has been built to predict the fixed bed breakthrough curves for single and dual-component system. This model considers both external and internal mass transfer resistances as well as axial dispersion with non-liner multi-component isotherm. The equilibrium isotherm model parameters such as isotherm model constants （qm and b）, pore diffusion coefficients （Dp） were obtained from batch experiments, while the external mass transfer coefficients and axial dispersion （kf, Dz） were calculated from empirical correlations. The results show that the general rate multi-component model was found suitable for describing the biosorption process of the dynamic behavior of the DAGS adsorber column and that DAGS can be used efficiently to remove organic and inorganic pollutants.展开更多
Charcoal gasification could mitigate the energetic problems in the rural zones since these regions have considerable amounts of wood, which is the base of such a fuel available. This paper presents some CFD （computat...Charcoal gasification could mitigate the energetic problems in the rural zones since these regions have considerable amounts of wood, which is the base of such a fuel available. This paper presents some CFD （computational fluid dynamic） predictions of the experimental results obtained from the fixed bed gasification of charcoal made in a pilot-scale downdraft reactor using air, which was designed and built by the Research Group in Clean Development Mechanisms and Energy Management, from the National University of Colombia. The quality of the syngas obtained from the process was evaluated through the CO and CO2 percentages measured in its composition. The performance at various air flow rates （measured at the system entrance, through an analog flow meter） is evaluated with the help of 11 thermocouples, which give the information to create a temperature profile, and three load cells to measure the solid fuel conversion rate. To simulate the process, the information from temperature profile, charcoal proximate analysis, air flow meter and load cells were taken as inputs and the syngas composition was obtained as the result from the calculation. The domain was defined as 2D with an axis-symmetric description, using quads as mesh elements. The calculation and results were performed in a CFD commercial code widely used for this type of simulations： ANSYS FLUENT. The predictions made by the software were validated with the experimental results obtained in the laboratory.展开更多
A series of experiments were performed on indigenously synthesized catalyst pallets of cobalt as a very active metal on ceramic support like SiC, A1203 ＆ TiO2 in a fixed bed reactor configuration with an aim to study...A series of experiments were performed on indigenously synthesized catalyst pallets of cobalt as a very active metal on ceramic support like SiC, A1203 ＆ TiO2 in a fixed bed reactor configuration with an aim to study the catalyst activity ＆ selectivity, chemical kinetics, design flexibility, temperature, pressure by characteristics diffusion distance. Catalyst pallets were prepared and then characterized by N2 adsorption, X-ray Diffraction, Scanning Electron Microscope, and Temperature Programmed Reduction. The results showed the Brunaner, Emmett and Teller area of SiC was the lowest among the three supports prepared for testing. However, its reducibility showed improvement with use of cobalt acetate, as a precursor, rather than cobalt nitrates. Mechanical strength and behavior was checked by the hardness testing machine. Fischer Tropsch （FT） synthesis experiments were performed in the fixed bed reactor set at 450-500 K and 2.3-2.5 MPa using synthetic gas having HJCO ration = 2.0. FT synthesis showed that cobalt/silicon carbide catalyst gives high CO conversion and lower methane selectivity, compared to Co/A1203 and Co/TiO2, as well as high C5＋ selectivity of almost 90%. Moreover, its stability was enhanced by the addition of Zr02, as without this addition, the Co/SiC interactions are weaker and can cause carbon sintering, and thus, the deactivation rate to increase.展开更多
基金the Natural Science Foundation of Shanxi Province,China(No.2011011023-2)for financial support
文摘Titanium silicalite-1(TS-1)films were synthesized on stainless steel plate,glass slide and monolith supports via an in-situ hydrothermal method.Characterization data showed that the formation of TS-1 films was easier on the porous flat support with rough surface such as monolith than on the smooth non-porous supports like glass slide and stainless steel plate.The film on the monolith had the highest uniformity and smallest size of crystals.The catalytic property of monolithsupported film was tested for epoxidation of allyl chloride(ACH)by H2O2in a fixed bed reactor.Under the condition of a methanol(solvent)/ACH(90% )/H2O2(30% )ratio of 12:1:1,a LHSV of 1.35 h-1and a temperature of 318 K,the conversion of allyl chloride and the selectivity to epichlorohydrin reached 79% and 51% ,respectively.
文摘Dried anaerobic granular sludge （DAGS） for removing phenol （organic） and lead （inorganic） pollutants from synthetic wastewater was examined in a fixed bed system. A general rate multi-component model has been built to predict the fixed bed breakthrough curves for single and dual-component system. This model considers both external and internal mass transfer resistances as well as axial dispersion with non-liner multi-component isotherm. The equilibrium isotherm model parameters such as isotherm model constants （qm and b）, pore diffusion coefficients （Dp） were obtained from batch experiments, while the external mass transfer coefficients and axial dispersion （kf, Dz） were calculated from empirical correlations. The results show that the general rate multi-component model was found suitable for describing the biosorption process of the dynamic behavior of the DAGS adsorber column and that DAGS can be used efficiently to remove organic and inorganic pollutants.
文摘Charcoal gasification could mitigate the energetic problems in the rural zones since these regions have considerable amounts of wood, which is the base of such a fuel available. This paper presents some CFD （computational fluid dynamic） predictions of the experimental results obtained from the fixed bed gasification of charcoal made in a pilot-scale downdraft reactor using air, which was designed and built by the Research Group in Clean Development Mechanisms and Energy Management, from the National University of Colombia. The quality of the syngas obtained from the process was evaluated through the CO and CO2 percentages measured in its composition. The performance at various air flow rates （measured at the system entrance, through an analog flow meter） is evaluated with the help of 11 thermocouples, which give the information to create a temperature profile, and three load cells to measure the solid fuel conversion rate. To simulate the process, the information from temperature profile, charcoal proximate analysis, air flow meter and load cells were taken as inputs and the syngas composition was obtained as the result from the calculation. The domain was defined as 2D with an axis-symmetric description, using quads as mesh elements. The calculation and results were performed in a CFD commercial code widely used for this type of simulations： ANSYS FLUENT. The predictions made by the software were validated with the experimental results obtained in the laboratory.
文摘A series of experiments were performed on indigenously synthesized catalyst pallets of cobalt as a very active metal on ceramic support like SiC, A1203 ＆ TiO2 in a fixed bed reactor configuration with an aim to study the catalyst activity ＆ selectivity, chemical kinetics, design flexibility, temperature, pressure by characteristics diffusion distance. Catalyst pallets were prepared and then characterized by N2 adsorption, X-ray Diffraction, Scanning Electron Microscope, and Temperature Programmed Reduction. The results showed the Brunaner, Emmett and Teller area of SiC was the lowest among the three supports prepared for testing. However, its reducibility showed improvement with use of cobalt acetate, as a precursor, rather than cobalt nitrates. Mechanical strength and behavior was checked by the hardness testing machine. Fischer Tropsch （FT） synthesis experiments were performed in the fixed bed reactor set at 450-500 K and 2.3-2.5 MPa using synthetic gas having HJCO ration = 2.0. FT synthesis showed that cobalt/silicon carbide catalyst gives high CO conversion and lower methane selectivity, compared to Co/A1203 and Co/TiO2, as well as high C5＋ selectivity of almost 90%. Moreover, its stability was enhanced by the addition of Zr02, as without this addition, the Co/SiC interactions are weaker and can cause carbon sintering, and thus, the deactivation rate to increase.
