Encapsulation of ultra-small Cu–Fe into ZSM-5 zeolites for NH3-SCR with broad reaction-temperature ranges

2022 ◽  
pp. 111675
Author(s):  
En-Hui Yuan ◽  
Meng Li ◽  
Ming-Hui Yang ◽  
Xiaosheng Huang ◽  
Kun Zhang ◽  
...  
Keyword(s):  
Reaction Temperature ◽  
Nh3 Scr ◽  
Temperature Ranges

The Effect of Si/Al Ratio on Selective Catalytic Reduction of NOx with NH3 over Pt/Al-SBA-15

2008 ◽  
Vol 135 ◽  
pp. 61-64
Author(s):  
Min Kang ◽  
Jae Hyun Park ◽  
Eun Duck Park ◽  
Ji Man Kim ◽  
Dae Jung Kim ◽  
...  
Keyword(s):  
Selective Catalytic Reduction ◽  
Reaction Temperature ◽  
Low Temperatures ◽  
Catalytic Reduction ◽  
Pt Catalysts ◽  
Nh3 Scr ◽  
Nox Conversion ◽  
Reduction Of Nox

The selective catalytic reduction of NOx with NH3 (NH3-SCR) was investigated over Pt catalysts supported on various supports such as alumina, ZSM-5, SBA-15, and Al-SBA-15 with different amounts of alumina. Among them, Pt catalysts supported on Al-SBA-15 showed the higher NOx conversion at low temperatures than those of others. These also showed high NOx conversions over a wide reaction temperature. As the Si/Al ratio in Al-SBA-15 decreased, the NH3-SCR activity increased. This was closely related to the amount of strongly-adsorbed NH3.

scholarly journals The Study of C3H6 Impact on Selective Catalytic Reduction by Ammonia (NH3-SCR) Performance over Cu-SAPO-34 Catalysts

Catalysts ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1327
Author(s):  
Yingfeng Duan ◽  
Lina Wang ◽  
Yagang Zhang ◽  
Wei Du ◽  
Yating Zhang
Keyword(s):  
Reaction Rate ◽  
Catalytic Reduction ◽  
Catalytic Performance ◽  
Coke Deposition ◽  
In Situ Drifts ◽  
Nh3 Scr ◽  
Nox Conversion ◽  
Temperature Ranges ◽  
And Performance

In present work, the catalytic performance of Cu-SAPO-34 catalysts with or without propylene during the NH3-SCR process was conducted, and it was found that the de-NOx activity decreased during low temperature ranges (<350 °C), but obviously improved within the range of high temperatures (>350 °C) in the presence of propylene. The XRD, BET, TG, NH3-TPD, NOx-TPD, in situ DRIFTS and gas-switch experiments were performed to explore the propylene effect on the structure and performance of Cu-SAPO-34 catalysts. The bulk characterization and TG results revealed that neither coke deposition nor the variation of structure and physical properties of catalysts were observed after C3H6 treatment. Generally speaking, at the low temperatures (<350 °C), active Cu2+ species could be occupied by propylene, which inhibited the adsorption and oxidation of NOx species, confining the SCR reaction rate and causing the deactivation of Cu-SAPO-34 catalysts. However, with the increase of reaction temperatures, the occupied Cu2+ sites would be recovered and sequentially participate into the NH3-SCR reaction. Additionally, C3H6-SCR reaction also showed the synergetic contribution to the improvement of NOx conversion at high temperature (>350 °C).

Understanding the mechanism of low temperature deactivation of Cu/SAPO-34 exposed to various amounts of water vapor in the NH3-SCR reaction

2019 ◽  
Vol 9 (14) ◽  
pp. 3623-3636 ◽  
Author(s):  
Jungwon Woo ◽  
Diana Bernin ◽  
Homayoun Ahari ◽  
Mark Shost ◽  
Michael Zammit ◽  
...  
Keyword(s):  
Water Vapor ◽  
Low Temperature ◽  
Exposure Time ◽  
Reaction Temperature ◽  
Water Exposure ◽  
Nh3 Scr

Water-exposure at 70 °C deteriorates Cu/SAPO-34, the extent of which depends on water exposure time, reaction temperature, and choice of SDAs.

scholarly journals Byproduct Analysis of SO2 Poisoning on NH3-SCR over MnFe/TiO2 Catalysts at Medium to Low Temperatures

Catalysts ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 265 ◽  
Author(s):  
Tsungyu Lee ◽  
Hsunling Bai
Keyword(s):  
Reaction Temperature ◽  
Catalytic Reduction ◽  
No Oxidation ◽  
Ammonium Salts ◽  
Oxidation Reactions ◽  
No Conversion ◽  
Nh3 Scr ◽  
So2 Poisoning ◽  
No Consumption ◽  
Nh3 Oxidation

The byproducts of ammonia-selective catalytic reduction (NH3-SCR) process over MnFe/TiO2 catalysts under the conditions of both with and without SO2 poisoning were analyzed. In addition to the NH3-SCR reaction, the NH3 oxidation and the NO oxidation reactions were also evaluated at temperatures of 100–300 °C to clarify the reactions occurred during the SCR process. The results indicated that major byproducts for the NH3 oxidation and NO oxidation tests were N2O and NO2, respectively, and their concentrations increased as the reaction temperature increased. For the NH3-SCR test without the presence of SO2, it revealed that N2O was majorly from the NH3-SCR reaction instead of from NH3 oxidation reaction. The byproducts of N2O and NO2 for the NH3-SCR reaction also increased after increasing the reaction temperature, which caused the decreasing of N2-selectivity and NO consumption. For the NH3-SCR test with SO2 at 150 °C, there were two decay stages during SO2 poisoning. The first decay was due to a certain amount of NH3 preferably reacted with SO2 instead of with NO or O2. Then the catalysts were accumulated with metal sulfates and ammonium salts, which caused the second decay of NO conversion. The effluent N2O increased as poisoning time increased, which was majorly from oxidation of unreacted NH3. On the other hand, for the NH3-SCR test with SO2 at 300 °C, the NO conversion was not decreased after increasing the poisoning time, but the N2O byproduct concentration was high. However, the SO2 led to the formation of metal sulfates, which might inhibit NO oxidation reactions and cause the concentration of N2O gradually decreased as well as the N2-selectivity increased.

scholarly journals Geometry-Controlled Carbon Coils by SF6 Flow Injection Time with Reaction Temperature

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Dong-Chul Kim ◽  
Sung-Hoon Kim
Keyword(s):  
Reaction Temperature ◽  
Flow Injection ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Sample Surface ◽  
Injection Time ◽  
Entire Sample ◽  
Entire Surface ◽  
Thermal Chemical Vapor Deposition ◽  
Temperature Ranges

Carbon nanocoils and/or microcoils were synthesized using C2H2 as the source gas along with the injection of SF6 as an incorporated additive gas under the thermal chemical vapor deposition (TCVD) system. To control the geometries of the carbon coils, we varied the SF6 flow injection time at different reaction temperature ranges. At the lowest reaction temperature (550°C), carbon microcoils were dominantly formed within a relatively short initial SF6 flow injection time (less than 5 min). By increasing the SF6 flow injection time, carbon nanocoils could be well developed on the entire surface of the sample. At 750°C, the formation of carbon microcoils dominated over the entire sample surface, irrespective of the SF6 flow injection time. Based on these results, the growth mechanism for the dominantly formed carbon coils was suggested and discussed. In addition, the causes for the dominant formation of carbon nanocoils and/or microcoils according to the SF6 flow injection times with the different reaction temperatures were analyzed.

Coke formation on HFAU and HEMT zeolites. Influence of the reaction temperature and propene pressure

1999 ◽  
Vol 96 (2) ◽  
pp. 303-318 ◽  
Author(s):  
G. A. Doka Nassionou ◽  
P. Magnoux ◽  
M. Guisnet
Keyword(s):  
Reaction Temperature ◽  
Coke Formation

The Influence of Reaction Temperature on the Size of the Catalyst Nano-particle and the Carbon Nanotube Diameter Distributions

2008 ◽  
Author(s):  
Enkeleda Dervishi ◽  
Zhongrui Li ◽  
Fumiya Watanabe ◽  
Yang Xu ◽  
Viney Saini ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Reaction Temperature ◽  
Nano Particle ◽  
Diameter Distributions

PEMBUATAN SURFAKTAN DARI ASAM OLEAT

2019 ◽  
Vol 1 (3) ◽  
pp. 68
Author(s):  
Puguh Setyopratomo ◽  
Edy Purwanto ◽  
H. Yefrico ◽  
H. Yefrico
Keyword(s):  
Oleic Acid ◽  
Optimum Condition ◽  
Reaction Temperature ◽  
Catalyst Concentration ◽  
Acid Number ◽  
Esterification Reaction ◽  
Number Density ◽  
Sample Analysis ◽  
Reaction Conversion ◽  
Glycerol Mono

The synthesis of glycerol mono oleic from oleic acid and glycerol is classified as an esterification reaction. This research is aimed to study the influent of reaction temperature and catalyst concentration on reaction conversion. During the experiment the temperature of reaction mixture was varied as 110 oC, 130 oC, and 150 oC, while the catalyst concentration of 1%, 3 %, and 5% was used. The batch experiment was conducted in a glass reactor equipped with termometer, agitator, and reflux condensor. The oleic acid – glycerol mol ratio of 1 : 2 was used as a mixture feed. To maintain the reaction temperature at certain level, the oil bath was used. After the temperature of reaction mixture was reached the expected value, then H2SO4 catalyst was added to the reactor.  To measure the extent of the reaction, every 30 minutes the sample was drawn out from the reactor vessel. The sample analysis include acid number, density, and viscosity measurement. From this research the optimum condition which is the temperature of reaction of 150 oC and 1% catalyst concentration was obtained. At this optimum condition the convertion reach 86% and the analysis of other physical properties of the product show the acid number of 24.12, the density of 0.922 g/cc, and the viscosity of 118.4 cp.

Optical and Electrical Properties of Organic Conducting Polymers

2014 ◽  
Vol 8 (1) ◽  
pp. 1457-1463
Author(s):  
Salah Abdulla Hasoon
Keyword(s):  
Electrical Properties ◽  
Conjugated Polymer ◽  
Polymeric Materials ◽  
Quantum Mechanical ◽  
Optical And Electrical Properties ◽  
Electrically Conducting ◽  
Temperature Ranges ◽  
Lithium Tetrafluoroborate ◽  
Absorbance Peak ◽  
Polymerization Method

Novel electrically conducting polymeric materials are prepared in this work. Polythiophene (PT) and poly (3-Methelthiophene) (P3MT) films were prepared by electro-polymerization method using cyclic voltammetry in acetonitrile as a solvent and lithium tetrafluoroborate as the electrolyte on a gold electrode. Electrical properties of P3MT have been examined in different environments using UV-Vis absorption spectroscopy and quantum mechanical ab initio calculations, The observed absorption peaks at 314 and 415 nm, were attributed to the n-π* and π-π* transitions, respectively in the conjugated polymer chain, in contrast, the observed absorbance peak at 649 nm, is responsible for electric conduction. The temperature dependence of the conductivity can be fitted to the Arrhenius and the VTF equations in different temperature ranges.

CARPENTER LOW EXPANSION 39

Alloy Digest ◽  
2004 ◽  
Vol 53 (10) ◽  
Keyword(s):  
Thermal Expansion ◽  
Physical Properties ◽  
Tensile Properties ◽  
Iron Alloy ◽  
Nickel Iron ◽  
Temperature Ranges ◽  
Technology Corporation ◽  
Carpenter Technology Corporation ◽  
Nickel Iron Alloy ◽  
Low Rate

Abstract Carpenter Low Expansion 39 alloy is a 39% nickel iron alloy with a low rate of thermal expansion useful to temperature ranges up to 316 deg C (600 deg F). This datasheet provides information on composition, physical properties, and tensile properties. It also includes information on joining. Filing Code: FE-132. Producer or source: Carpenter Technology Corporation.

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