Effect of Silica-Alumina Ratio of Catalysts on NO Decomposition Rate in Cement Kiln Exhaust

2020 ◽  
Vol 993 ◽  
pp. 1450-1455
Author(s):  
Yan Ling Gan ◽  
Su Ping Cui ◽  
Xiao Yu Ma ◽  
Ya Li Wang
Keyword(s):  
Surface Area ◽  
Decomposition Rate ◽  
Catalytic Decomposition ◽  
Nitrogen Adsorption ◽  
No Decomposition ◽  
Bet Surface Area ◽  
Cement Kiln ◽  
Average Pore ◽  
Silica Alumina ◽  
Silica Alumina Ratio

In order to deal with the pollution of NO in cement kiln exhaust, the study of NO catalytic decomposition catalyst obtained much more attention. The effect of silica-alumina ratio on NO decomposition rate in cement kiln without other reductant was studied. The NO decomposition rate of catalysts with different silica-alumina ratio was determined by infrared spectrometer. And pore structures and the microstructure of the catalyst were characterized separately by BET surface area, nitrogen adsorption-desorption and XRD. The results show that silica-alumina ratio of catalyst was preferred to be 50 with the best NO decomposition rate when the temperature was below 300 °C. The catalyst with silica-alumina ratio of 60 has the higher catalytic activity when the temperature was higher than 300 °C, and the decomposition rate achieved 70% at 600 °C. XRD results shows the crystallinity of catalysts increased as the silica-alumina ratio increased. BET surface area and the cumulative pore volume of catalysts gradually increased, and the average pore diameter gradually reduced with the increase of silica-alumina ratio.

Influence of Catalysts with Different Templates on Direct Decomposition of NO in Cement Kiln Exhaust

2018 ◽  
Vol 913 ◽  
pp. 948-953
Author(s):  
Yan Ling Gan ◽  
Su Ping Cui ◽  
Hong Xia Guo ◽  
Xiao Yu Ma ◽  
Ya Li Wang
Keyword(s):  
Surface Area ◽  
Decomposition Rate ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Direct Decomposition ◽  
No Decomposition ◽  
Bet Surface Area ◽  
Cement Kiln ◽  
Porous Catalyst ◽  
Decomposition Of No

The influence of catalysts with different templates on direct decomposition of NO in cement kiln exhaust was studied in this paper. The NO direct decomposition rate of porous catalyst materials with different templates was determined by infrared spectrometer. And pore structure and the microstructure of the catalysts were characterized by BET surface area, nitrogen adsorption-desorption. The results show that the catalytic performance of porous catalyst without any template is better than catalysts with other templates at low temperature. When the temperature reached 550 °C, NO decomposition rate of porous catalyst with CTAB could reach to more than 80%. And meanwhile, the catalysts with organic template reagent have higher BET surface area than those with inorganic template agent. With the increasing of the reaction time, the NO decomposition rate decreases. After reaction for 3 hours, the decomposition rate decreases from 80% to 40%.

scholarly journals Hydrothermal Synthesis of Silicoaluminophosphate with AEL Structure Using a Residue of Fluorescent Lamps as Starting Material

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7366
Author(s):  
Gidiângela C. C. S. Lima ◽  
Mariele I. S. Mello ◽  
Lindiane Bieseki ◽  
Antonio S. Araujo ◽  
Sibele B. C. Pergher
Keyword(s):  
Surface Area ◽  
Molecular Sieves ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Molar Ratio ◽  
Crystallization Time ◽  
Fluorescent Lamp ◽  
Alternative Source ◽  
X Ray ◽  
Silica Alumina

Silicoaluminophosphate molecular sieves of SAPO-11 type (AEL structure) were synthesized by the hydrothermal method, from the residue of a fluorescent lamp as a source or Si, Al, and P in the presence of water and di-propyamine (DPA) as an organic template. To adjust the P2O5/SiO2 and Si/Al and ratios, specific amounts of silica, alumina, or alumina hydroxide and orthophosphoric acid were added to obtain a gel with molar chemical composition 1.0 Al2O3:1.0 P2O5:1.2 DPA:0.3 SiO2:120 H2O. The syntheses were carried out at a temperature of 473 K at crystallization times of 24, 48, and 72 h. The fluorescent lamp residue and the obtained samples were characterized by X-ray fluorescence, X-ray diffraction, scanning electron microscopy, and BET surface area analysis using nitrogen adsorption isotherms. The presence of fluorapatite was detected as the main crystalline phase in the residue, jointly with considered amounts of silica, alumina, and phosphorus in oxide forms. The SAPO-11 prepared using aluminum hydroxide as Al source, P2O5/SiO2 molar ratio of 3.6 and Si/Al ratio of 0.14, at crystallization time of 72 h, achieves a yield of 75% with a surface area of 113 m2/g, showing that the residue from a fluorescent lamp is an alternative source for development of new materials based on Si, Al, and P.

Hydrothermal Synthesis of Nanorods/Nanoparticles TiO2 for Photocatalytic Activity and Dye-sensitized Solar Cell Applications

2006 ◽  
Vol 951 ◽  
Author(s):  
Sorapong Pavasupree ◽  
Supachai Ngamsinlapasathian ◽  
Yoshikazu Suzuki ◽  
Susumu Yoshikawa
Keyword(s):  
Photocatalytic Activity ◽  
Surface Area ◽  
Pore Diameter ◽  
Mesoporous Structure ◽  
Energy Conversion Efficiency ◽  
Bet Surface Area ◽  
Average Pore ◽  
Dye Sensitized ◽  
Prepared Material ◽  
20 Nm

ABSTRACTNanorods/nanoparticles TiO2 with mesoporous structure were synthesized by hydrothermal method at 150 °C for 20 h. The samples characterized by XRD, SEM, TEM, SAED, HRTEM, and BET surface area. The nanorods had diameter about 10-20 nm and the lengths of 100-200 nm, the nanoparticles had diameter about 5-10 nm. The prepared material had average pore diameter about 7-12 nm. The BET surface area and pore volume of the sample are about 203 m2/g and 0.655 cm3/g, respectively. The nanorods/nanoparticles TiO2 with mesoporous structure showed higher photocatalytic activity (I3− concentration) than the nanorods TiO2, nanofibers TiO2, mesoporous TiO2, and commercial TiO2 (ST-01, P-25, JRC-01, and JRC-03). The solar energy conversion efficiency (η) of the cell using nanorods/nanoparticles TiO2 with mesoporous structure was about 7.12 % with Jsc of 13.97 mA/cm2, Voc of 0.73 V and ff of 0.70; while η of the cell using P-25 reached 5.82 % with Jsc of 12.74 mA/cm2, Voc of 0.704 V and ff of 0.649.

Synthesis of a novel visible light responsive γ-Fe2O3/SiO2/C-TiO2 magnetic nanocomposite for water treatment

2018 ◽  
Vol 78 (12) ◽  
pp. 2500-2510 ◽  
Author(s):  
Henry H. Mungondori ◽  
Spencer Ramujana ◽  
David M. Katwire ◽  
Raymond T. Taziwa
Keyword(s):  
Water Treatment ◽  
Visible Light ◽  
Surface Area ◽  
Fine Particles ◽  
Uv Light ◽  
Sol Gel ◽  
Spherical Shape ◽  
Solar Irradiation ◽  
Bet Surface Area ◽  
Average Pore

AbstractThis work investigates the preparation of a magnetically recoverable photocatalytic nanocomposite of maghemite nanoparticles coated with silica and carbon doped titanium dioxide. The novel nanocomposite boasts the advantages of efficient photocatalytic degradation of organic pollutants in water and ease of recovery of the fine particles after water treatment. The photocatalytic nanocomposite was successfully synthesized through a stepwise approach via co-precipitation and sol-gel methods. Characterisation by Fourier transform infrared (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) substantiated the existence of the intended structure of the nanocomposite and the particles were found to be in the size range of 15–22 nm with a quasi-spherical shape. Brunauer–Emmett–Teller (BET) surface area analysis revealed an average surface area of 55.20 m2/g, which is higher than that of commercial TiO2 (Degussa P25, 50.00 m2/g), and an average pore diameter of 8.36 nm. A 5 ppm methylene blue solution was degraded with an efficiency of 96.8% after 3 h of solar irradiation, which was 19.7% greater than using the same photo-catalyst under strict UV light irradiation. Photo-catalysis using these nanoparticles was observed to be very effective. The prepared novel visible light active nanocomposite has great potential for incorporation into water treatment systems because it exhibits good stability and magnetism, as well as high photocatalytic efficiency.

Nano/Micro Pore Structure and Fractal Characteristics of Baliancheng Coalfield in Hunchun Basin

2021 ◽  
Vol 21 (1) ◽  
pp. 682-692
Author(s):  
Youzhi Wang ◽  
Cui Mao
Keyword(s):  
Fractal Dimension ◽  
Specific Surface ◽  
Pore Structure ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Diameter ◽  
Fractal Dimensions ◽  
Nitrogen Adsorption ◽  
Average Pore ◽  
Coal Reservoir

The pore structure characteristic is an important index to measure and evaluate the storage capacity and fracturing coal reservoir. The coal of Baliancheng coalfield in Hunchun Basin was selected for experiments including low temperature nitrogen adsorption method, Argon Ion milling Scanning Electron Microscopy (Ar-SEM), Nuclear Magnetic Resonance (NMR), X-ray diffraction method, quantitative mineral clay analysis method. The pore structure of coal was quantitatively characterized by means of fractal theory. Meanwhile, the influences of pores fractal dimension were discussed with experiment data. The results show that the organic pores in Baliancheng coalfield are mainly plant tissue pores, interparticle pores and gas pores, and the mineral pores are corrosion pores and clay mineral pores. There are mainly slit pore and wedge-shaped pore in curve I of Low temperature nitrogen adsorption. There are ink pores in curve II with characteristics of a large specific surface area and average pore diameter. The two peaks of NMR T2 spectrum indicate that the adsorption pores are relatively developed and their connectivity is poor. The three peaks show the seepage pores and cracks well developed, which are beneficial to improve the porosity and permeability of coal reservoir. When the pore diameter is 2–100 nm, the fractal dimensions D1 and D2 obtained by nitrogen adsorption experiment. there are positive correlations between water content and specific surface area and surface fractal dimension D1, The fractal dimension D2 was positively and negatively correlated with ash content and average pore diameters respectively. The fractal dimensions DN1 and DN2 were obtained by using the NMR in the range of 0.1 μm˜10 μm. DN1 are positively correlated with specific surface area of adsorption pores. DN2 are positively correlated volume of seepage pores. The fractal dimension DM and dissolution hole fractal dimension Dc were calculated by SEM image method, respectively controlled by clay mineral and feldspar content. There is a remarkable positive correlation between D1 and DN1 and Langmuir volume of coal, so fractal dimension can effectively quantify the adsorption capacity of coal.

APPARENT DENSITIES AND INTERNAL SURFACE AREAS OF SELECTED CARBON BLACKS

1962 ◽  
Vol 40 (2) ◽  
pp. 184-188 ◽  
Author(s):  
P. L. Walker Jr. ◽  
W. V. Kotlensky
Keyword(s):  
Surface Area ◽  
Pore Diameter ◽  
Internal Surface ◽  
Nitrogen Adsorption ◽  
Roughness Factor ◽  
Internal Surface Area ◽  
Average Pore ◽  
Carbon Blacks ◽  
Surface Areas ◽  
Nitrogen Adsorption Isotherms

It is shown that the open pore volume within carbon blacks can be calculated from nitrogen adsorption isotherms (77°K) on the blacks. From this volume and a helium density, the apparent density of a black can be calculated. Other properties of the blacks which then can be calculated are free surface area, internal surface area, surface roughness factor, and the average pore diameter of the internal surface. These data are presented for five selected carbon blacks.

Methanol Conversion to Propylene over Mo-HZSM-5 Zeolite

2013 ◽  
Vol 834-836 ◽  
pp. 476-480
Author(s):  
Hai Rong Zhang ◽  
Hong Yan Liu ◽  
Yu Jiang ◽  
Xiao Hua Chang ◽  
Kai Yuan ◽  
...  
Keyword(s):  
Hydrothermal Method ◽  
Surface Area ◽  
Fixed Bed ◽  
Nitrogen Adsorption ◽  
Methanol Conversion ◽  
Catalytic Performance ◽  
Bet Surface Area ◽  
Al Content ◽  
Strong Acidity

A series of Mo-ZSM-5 zeolites have been synthesized by in site hydrothermal method and their catalytic performance for methanol conversion to propylene was tested in a fixed bed reaction at WHSV=4 h-1, pressure of 1 atm, and MeOH/H2O (mol) ratio of 1. The effect of Mo and Al content on the structure and acidity of Mo-ZSM-5 zeolites were characterized by nitrogen adsorption and NH3-TPD. The results showed that Mo incorporation gradually decreased the BET surface area and weaken the strong acidity on the surface of the zeolites. At 470 °C, the maximum selectivity of propylene and the P/E (Propylene to Ethane) ratio were achieved 45.04 % and 7.30, which were higher than those over Mo free HZSM-5 by 4.12% and 3.47, respectively. Mo-ZSM-5 zeolites are promising catalysts for methanol conversion to propylene with a high P/E.

An Experimental Analysis of Lactic Acid Esterification Process Using Langmuir-Hinshelwood Model

2017 ◽  
Vol 733 ◽  
pp. 36-41
Author(s):  
Edidiong Okon ◽  
Habiba Shehu ◽  
Edward Gobina
Keyword(s):  
Lactic Acid ◽  
Cation Exchange ◽  
Pore Size ◽  
Surface Area ◽  
Cation Exchange Resin ◽  
Nitrogen Adsorption ◽  
Bet Surface Area ◽  
Gas Chromatography Mass Spectrometry ◽  
Type Iv ◽  
Exchange Resins

In this study, esterification of lactic acid and ethanol to produce ethyl lactate using different cation-exchange resin catalysts was performed at 100 °C. The catalysts used for the esterification process were amberlyst 16 and dowex 50W8x cation-exchange resins. Two simplified mechanisms based on Langmuir-Hinshelwood model were employed to describe the components that adsorbed most on the surface of the catalysts. Fourier Transform Infrared (Nicolet iS10 FTIR) was employed to verify the rationality of the mechanisms. FTIR of the esterification product reflected C=O, H=O and C=C bonds on the spectra confirming water and ethanol as the most adsorbed components. The kinetic study of the retention time and the peak areas of the esterification produced with the different catalysts were compared using an autosampler gas chromatography/mass spectrometry (autosampler GC-MS). The chromatogram of the esterification product catalysed by amberlyst 16 showed a faster elution at 1.503 mins with the peak area of 1229816403 m2 in contrast to the dowex 50W8x. The BET surface area and BJH pore size distribution of the resin catalysts were determined using liquid nitrogen adsorption (Quantachrome, 2013) at 77 K. The BET surface area results of amberlyst 16 resin catalysts was found to be 1.659m2/g compared to 0.1m2/g for the dowex 50W8x. The BJH results of the catalysts exhibited a type IV isotherm with hysteresis confirming that the materials were mesoporous with pore size in the region of 2 – 50 nm.

scholarly journals Production of Highly Porous Biochar Materials from Spent Mushroom Composts

Horticulturae ◽  
2022 ◽  
Vol 8 (1) ◽  
pp. 46
Author(s):  
Wen-Shing Chen ◽  
Wen-Tien Tsai ◽  
Yu-Quan Lin ◽  
Chi-Hung Tsai ◽  
Yao-Tsung Chang
Keyword(s):  
Surface Area ◽  
Agricultural Waste ◽  
Average Pore Size ◽  
Chemical Properties ◽  
Edible Mushroom ◽  
Bet Surface Area ◽  
Mushroom Compost ◽  
Average Pore ◽  
Spent Mushroom Compost ◽  
Pore Properties

The edible mushroom industry has grown significantly in recent years due to the dietary change and the demand for heathy food. However, the spent mushroom compost (SMC) will be produced in large quantities after the harvest, thus forming an agricultural waste requiring proper management other than dumping or burning. In this work, two types of SMCs with the cultivation of shiitake fungus (SF) and black fungus (BF) were converted into porous biochar products (a series of SMC-SF-BC and SMC-BF-BC) at higher pyrolysis temperatures (i.e., 400, 600 and 800 °C) based on their thermochemical characteristics, using thermogravimetric analysis (TGA). The pore and chemical properties of the resulting products, including surface area, pore volume, average pore size, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and Fourier Transform infrared spectroscopy (FTIR), were studied to correlate them with the most important process parameter. The results showed that the pore properties of the biochar products indicated a significant increase with the increase in the pyrolysis temperature from 400 to 600 °C. The data on the maximal Brunauer-Emmett-Teller (BET) surface area for the biochar products produced at 800 °C (i.e., SMC-SF-BC-800 and SMC-BF-BC-800) were found to be 312.5 and 280.9 m2/g, respectively. Based on the EDS and FTIR, plenty of oxygen-containing functional groups were found on the surface of the resulting biochar products.

scholarly journals Preparation of Cu-Al/SiO2 Porous Material and Its Effect on NO Decomposition in a Cement Kiln

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 145
Author(s):  
Yanling Gan ◽  
Suping Cui ◽  
Xiaoyu Ma ◽  
Hongxia Guo ◽  
Yali Wang
Keyword(s):  
Porous Material ◽  
Decomposition Rate ◽  
Active Phase ◽  
Mesoporous Structure ◽  
Atmospheric Environment ◽  
No Decomposition ◽  
Material Structure ◽  
Cement Kiln ◽  
X Ray Diffraction ◽  
Infrared Spectrometer

Nitrogen oxide (NOx) emissions have attracted much attention for increasing concern on the quality of the atmospheric environment. In view of NO decomposition in the cement production process, the preparation of Cu-Al/SiO2 porous material and its effect on NO decomposition were studied, and the denitrification mechanism was proposed in this paper. The NO decomposition performance of the Cu-Al/SiO2 porous material was tested via the experimental setup and infrared spectrometer and micro gas chromatography (GC). The result shows that the Cu-Al/SiO2 porous material with the template of cetyltrimethylammonium bromide (CTAB) had a better NO decomposition rate than materials with other templates when the temperature was above 500 °C, and NO decomposition rate could approach 100% at high temperatures above 750 °C. Structure analysis indicates that the prepared Cu-Al/SiO2 material structure was a mesoporous structure. The X-Ray Diffraction (XRD) and Ultraviolet–visible spectrophotometry (UV–Vis) results of the denitrification product show that the Cu-Al/SiO2 material mainly decomposed to Cu2O and Si2O, and the CuO decomposed to Cu2O and O2 at high temperature. The Cu(I)O was considered as the active phase. The redox process between Cu(II)O and Cu(I)O was thought to be the denitrification mechanism of the Cu-Al/SiO2 porous material.

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