The W Loading Effect on SCR deNOx Performance for V-W-Mo/TiO2 Catalyst

2013 ◽  
Vol 774-776 ◽  
pp. 743-746 ◽  
Author(s):  
Ji Wei Peng ◽  
Tao Luan ◽  
Yan Gao
Keyword(s):  
High Temperature ◽  
Fixed Bed ◽  
Catalytic Efficiency ◽  
Fixed Bed Reactor ◽  
Exhaust Gas ◽  
Gas Composition ◽  
High Temperature Region ◽  
Loading Effect ◽  
Scr Catalysts ◽  
Temperature Window

The SCR catalysts were produced with V2O5, WO3, MoO3and anatase type TiO2. The catalyst samples were ground and sieved for 0.3~0.6mm.The NO catalytic efficiency, selectivity against N2O of the catalysts were investigated on a fixed bed reactor under simulated exhaust gas with a typical gas composition. The addition of W enhanced the catalytic efficiency of V(1)-W(x)-Mo (4.5)/TiO2catalysts at high temperature region, while lessened that at low temperature. Increasing the loading of W from 1.5% w/w to 4.5% w/w advanced the maximum catalytic efficiency from 88% to 99% and enlarged the temperature window of the catalyst. The presence of W promoted the N2O generation. The V(1)-W(4.5)-Mo (4.5)/TiO2catalyst showed higher catalytic selectivity for NO compared to the catalysts loading W.

The Mo Loading Effect on SCR deNOx Performance for V-W-Mo/TiO2 Catalyst

2012 ◽  
Vol 229-231 ◽  
pp. 126-129 ◽  
Author(s):  
Yan Gao ◽  
Tao Luan ◽  
Tao Lv ◽  
Hong Ming Xu
Keyword(s):  
High Temperature ◽  
Fixed Bed ◽  
Catalytic Efficiency ◽  
Fixed Bed Reactor ◽  
Exhaust Gas ◽  
Impregnation Method ◽  
Gas Composition ◽  
Loading Effect ◽  
Tio2 Catalyst ◽  
Temperature Window

The V(1)-W(4.5)-Mo(x)/TiO2 catalysts was prepared by the incipient dry impregnation method. The catalyst samples were ground and sieved for 0.3~0.6 mm. The NO catalytic efficiency, selectivity against N2O of the catalysts were investigated on a fixed bed reactor under simulated exhaust gas with a typical gas composition. The addition of Mo enhanced the catalytic efficiency of V(1)-W(4.5)-Mo(x)/TiO2 catalysts at low temperature region, while lessened that at high temperature, especially at the temperature above 400 °C. Increasing the loading of Mo from 1.5% w/w to 4.5% w/w advanced the maximum catalytic efficiency from 78% to 99% and enlarged the temperature window of the catalyst. The acceptable NO conversion (>60%) was attained at temperature as low as 240 °C for V(1)-W(4.5)-Mo(7.5)/TiO2 catalyst. The presence of Mo promoted the N2O generation. The V(1)-W(4.5)-Mo(0)/TiO2 catalyst showed higher catalytic selectivity for NO compared to the catalysts loading Mo.

Design of a Flow Reactor for Testing Multi-Brick Catalyst Systems Using Rapid Exhaust Gas Composition Switches

2009 ◽  
Author(s):  
Stefan Klinkert ◽  
John W. Hoard ◽  
Sakthish R. Sathasivam ◽  
Dennis N. Assanis ◽  
Stanislav V. Bohac
Keyword(s):  
Flow Reactor ◽  
Combustion Engine ◽  
Synergistic Effects ◽  
Control Program ◽  
Exhaust Gas ◽  
Gas Composition ◽  
Lean Burn ◽  
Exhaust Gas Aftertreatment ◽  
Scr Catalysts ◽  
Catalyst Systems

In recent years, diesel exhaust gas aftertreatment has become a core combustion engine research subject because of both increasingly stringent emission regulations and incentives toward more fuel-efficient propulsion systems. Lean NOX traps (LNT) and selective catalytic reduction (SCR) catalysts represent two viable pathways for the challenging part of exhaust gas aftertreatment of lean burn engines: NOX abatement. It has been found that the combination of LNT and SCR catalysts can yield synergistic effects. Switches in the operation mode of the engine, temporarily enriching the mixture, are required to regenerate the LNT catalyst and produce ammonia for the SCR. This paper describes the design of a catalyst flow reactor that allows studying multi-brick catalyst systems using rapid exhaust gas composition switches and its initial validation. The flow reactor was designed primarily to study the potential of combining different aftertreatment components. It can accommodate two sample bricks at a time in two tube furnaces, which allows for independent temperature control. Moreover, the flow reactor allows for very flexible control of the composition and flow rate of the synthetic exhaust, which is blended using mass flow controllers. By using a two-branch design, very fast switches between two exhaust gas streams, as seen during the regeneration process of a LNT catalyst, are possible. The flow reactor utilizes a variety of gas analyzers, including a 5-Hz FTIR spectrometer, an emissions bench for oxygen and THC, a hydrogen mass spectrometer, and gas chromatographs for HC speciation. An in-house control program allows for data recording, flow reactor control, and highly flexible automation. Additionally, the hardware and software incorporate features to ensure safe testing. The design also has provisions for engine exhaust sampling.

scholarly journals High‐Pressure High‐Temperature Transparent Fixed‐Bed Reactor for Operando Gas‐Liquid Reaction Follow‐up

2019 ◽  
Vol 42 (3) ◽  
pp. 655-660 ◽  
Author(s):  
Marisa De Sousa Duarte ◽  
Matthieu Rolland ◽  
Corinne Sagnard ◽  
Didier Suire ◽  
Frederic Flacher ◽  
...  
Keyword(s):  
High Pressure ◽  
High Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Liquid Reaction ◽  
High Pressure High Temperature

High-Temperature HCl Removal with Sorbents in a Fixed-Bed Reactor

2003 ◽  
Vol 17 (4) ◽  
pp. 874-878 ◽  
Author(s):  
Binlin Dou ◽  
Jinsheng Gao ◽  
Seung Wook Baek ◽  
Xingzhong Sha
Keyword(s):  
High Temperature ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Hcl Removal

Effects of Zn on Steam Gasification Characteristics of Shenhua Lignite Char

2014 ◽  
Vol 1008-1009 ◽  
pp. 252-256
Author(s):  
Wipawan Sangsanga ◽  
Jin Xiao Dou ◽  
Zhe Lei Tong ◽  
Jiang Long Yu
Keyword(s):  
Gas Chromatography ◽  
Catalytic Activity ◽  
Fixed Bed ◽  
Steam Gasification ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Gas Composition ◽  
Gaseous Products ◽  
Lignite Char ◽  
Catalytic Effects

The catalytic effects of Zn on the yield of the gaseous products during steam gasification of lignite char were investigated by using a fixed-bed reactor. The gas composition was measured using a gas chromatography (GC). The experimental results show that Zn has catalytic effects on steam gasification and increased the yield of H2. There was an optimum content of Zn implanted into the coal above which zinc does not show further catalytic activity.

A kinetic study of gaseous potassium capture by coal minerals in a high temperature fixed-bed reactor

Fuel ◽  
2008 ◽  
Vol 87 (15-16) ◽  
pp. 3304-3312 ◽  
Author(s):  
Yuanjing Zheng ◽  
Peter Arendt Jensen ◽  
Anker Degn Jensen
Keyword(s):  
High Temperature ◽  
Kinetic Study ◽  
Fixed Bed ◽  
Fixed Bed Reactor

SER Process Variable Evaluation for the Production of Hydrogen using Calcined Dolomite

2011 ◽  
Vol 14 (2) ◽  
pp. 121-126
Author(s):  
A. Lopez-Ortiz ◽  
V. Collins-Martinez ◽  
D. P. Harrison
Keyword(s):  
Fixed Bed ◽  
Catalyst Particle ◽  
Process Variable ◽  
Fixed Bed Reactor ◽  
Particle Sizes ◽  
Gas Composition ◽  
Co2 Diffusion ◽  
Production Of Hydrogen ◽  
Kinetic Effects ◽  
Co2 Absorbent

Reaction performance of the sorption enhanced reforming (SER) process for the production of hydrogen was studied using commercial dolomite as inexpensive solid CO2 absorbent. The combined reforming, shift, and CO2 separation reactions were studied using a laboratory-scale fixed-bed reactor as a function of temperature, feed gas composition, dolomite type, and dolomite and catalyst particle sizes. Reactor was loaded with a mixture of calcined dolomite (≈ 23g) and a commercial reforming catalyst (NiO/Al2O3, ≈ 10g). Temperature was varied from 550 to 650°C at 15 atm. Feed gas composition was varied from 6 to 20% CH4/balance N2 and steam, with a feed H2O/CH4 ratio = 4. Two sources of dolomite were used; Rockwell and Stonelite. Particle sizes of dolomite and catalyst were 75>dp>150 μm and 300>dp>425 μm, respectively and were inversely varied. Results show that at 550°C Ca(OH)2 formation is possible, thus reducing the available CaO for carbonation, negatively affecting the performance of the SER system, while 650°C reached the SER thermodynamic equilibrium (TE). The use of dolomite approached the TE of the feed gas compositions studied, disregarding of its source. Kinetic effects observed in the tests suggest that small dolomite and large catalyst particles favor the decrease of CO2 diffusion effects.

Regeneration of Iron Oxide Sorbent Used for Hot Gas Desulfurization

2011 ◽  
Vol 396-398 ◽  
pp. 1170-1173
Author(s):  
Hui Ling Fan ◽  
Hong Sheng Guo ◽  
Li Tong Liang ◽  
Fang Shen ◽  
Jian Ying Lin ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Red Mud ◽  
Fixed Bed ◽  
Experimental Results ◽  
Fixed Bed Reactor ◽  
Gas Composition ◽  
Hot Gas ◽  
Regeneration Condition ◽  
Hot Gas Desulfurization

Iron oxide sorbent was prepared from red mud and the regeneration behaviors were investigated in a fixed bed reactor. Regeneration parameters including temperature and concentration of oxygen have been considered in order to obtain a suitable regeneration condition. XRD and SEM techniques were used to characterize the fresh and regenerated sorbents. The experimental results show that the sulfided sorbent could be regenerated efficiently using a gas composition of 2% O2-15% H2O- balance N2, at the temperature of 700 °C.

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