Innovative lines of SCR catalysis: NOx reduction for stationary diesel engine exhaust gas and dioxin abatement for waste incineration facilities

Hums, Erich; Joisten, Michael; Muller, R.; Sigling, R.; Spielmann, H. Peter

doi:10.1016/0920-5861(95)00205-7

Cited by 19 publications

(8 citation statements)

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“…Most of them are based on an Eley-Rideal or a Langmuir-Hinselwood mechanism. On the basis of IR an Eley-Rideal type mechanism involving gaseous or weakly adsorbed nitric oxide and ammonia adsorbed as NH 4 + was proposed by Inomata et al (1980) and Miyamoto et al (1982). Janssen et al (1987) further supported this mechanism by transient isotopic studies with labeled oxygen and Gasior et al (1988) found from IR and X-ray photoelectron spectroscopy (XPS) measurements that the reaction proceeds via participation of ammonia adsorbed on Brønsted acid sites.…”

Section: Introductionmentioning

confidence: 92%

High-Performance Aerogel DeNO_x Catalyst: Catalytic Behavior and Kinetic Modeling

Willi

Köppel

Baiker

1997

Ind. Eng. Chem. Res.

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The kinetics and the parametric sensitivity of the selective catalytic reduction of NO by NH3 were investigated for a high surface area vanadia−titania aerogel. The catalyst showed high activity at low temperatures and the selectivity to N2 was higher than 99% for all experimental conditions investigated. The addition of up to 2% H2O to the dry feed notably reduced the rate of NO conversion. The effect leveled off for higher H2O concentrations. In the absence of O2 in the feed the activity collapsed, independently whether water was present or not. Small amounts of oxygen resulted in a sharp increase of the reaction rate, but for oxygen concentrations exceeding 4%, the increase diminished. A high tolerance with respect to sulfur dioxide was observed. The estimated activation energy amounted to 60 ± 1 kJ/mol. The microkinetic analysis resulted in a model based on an Eley−Rideal mechanism which describes the kinetic behavior over a wide experimental range.

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Section: Introductionmentioning

confidence: 92%

High-Performance Aerogel DeNO_x Catalyst: Catalytic Behavior and Kinetic Modeling

Willi

Köppel

Baiker

1997

Ind. Eng. Chem. Res.

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“…In this context, one of the most important driving forces is the development of ammonia sensors for controlling DeNOx SCR catalysts (SCR=selective catalytic reduction) in automotive applications 11. These catalysts minimize NO x emission in exhaust gases by using ammonia as a reducing agent 12–14. An ammonia sensor is needed to control the amount of ammonia injected to achieve full conversion and to ensure that no ammonia is emitted.…”

Section: Introductionmentioning

confidence: 99%

Solvate‐Supported Proton Transport in Zeolites

Franke

Simon

2004

ChemPhysChem

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Solvate-supported proton transport in zeolite H-ZSM-5 was studied by means of complex impedance spectroscopy. The zeolite shows enhanced proton mobility in the presence of NH3 and H2O that depends on the concentration of the solvate molecule, temperature (298-773 K), and the SiO2/Al2O3 ratio of the zeolite (30-1000). In general, proton conductivity in H-ZSM-5 is most effectively supported in the presence of NH3 and H2O at high concentrations, low temperatures, and low SiO2/Al2O3 ratios (< or = 80). For the aluminum-rich samples desorption measurements reflect different transport mechanisms that depend on the respective temperature range. Up to about 393 K a Grotthus-like proton transport mechanism is assumed, whereas at higher temperatures (393-473 K) vehiclelike transport seems to dominate. The activation energies for NH4+ and H3O+ vehicle conductivity depend on the SiO2/Al2O3 ratio, and the values are in the range of 49-59 and 39-49 kJ mol-1, respectively, and thus significantly lower than those for "pure" proton conduction in solvate-free samples.

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“…Stoll et al also identified a very negative influence of water on the conversion of mono-and 1,2 di-chlorobenzene model compounds under these conditions. The SCR catalyst is normally very stable, and no significant loss of activity for dioxin removal over 50 000 h of operation has been reported [122]. The results were fitted to a Langmuir-Hinshelwood model [116].…”

Section: Dioxinsmentioning

confidence: 99%

Flue Gases from Stationary Sources

Gabrielsson

Pedersen

2008

Handbook of Heterogeneous Catalysis

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The sections in this article are Emissions from Stationary Sources Drivers for Flue Gas Cleaning Technology The USA E urope A sia C hina J apan NO x Removal Technologies Nitrous Oxide (N 2 O) Selective Catalytic Reduction ( SCR ) SCR Technology SCR Catalysts Different Catalyst Types Choice of Carrier Optimization of Activity The Effect of Increasing V 2 O 5 Loading Activation Energy as a Function of Vanadium Content The Effect of Co‐Oxides SCR Reaction Mechanism for Vanadium Catalysts: the Eley–Rideal Route Global Kinetics The Importance of B rønsted Acidity The Influence of Reoxidation or NO 2 The Influence of Gas Composition on Reaction Rate The Influence of Water The Influence of O 2 Modeling Definition of Different Model Types Estimation of Interphase Mass Transfer Intraporous Mass Transfer Kinetic Expressions The Feasibility of Different Models Deactivation Chemical Poisoning Surface Fouling, Pore and Channel Clogging Sintering Catalyst Management and Regeneration SCR Catalyst Testing Laboratory‐ and Bench‐Scale Testing Pilot‐Scale Testing Slip‐Stream Reactors Full‐Scale Catalyst Testing Gas Sampling and Analysis Other Emissions Sulfur Removal The Wet Sulfuric Acid ( WSA ) Process and Combined WSA and De NO x ( SNOX ) Hydrogen Sulfide Carbon Monoxide Carbon Dioxide Hydrocarbons Dioxins Hg Oxidation and Capture Hg Oxidation Thermodynamics Hg Removal from Coal‐Fired Power Plants A Conventional Flue Gas Cleaning Processes B Sorbent Injection, Coal Additives, and Coal Blending Hg Oxidation Mechanism and Catalysis Alternative Processes Multipollutant Processes The DESONOX Process Other Combined Processes Catalytic Filters New Technologies Plasma‐Assisted Processes Photocatalytic Processes

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Innovative lines of SCR catalysis: NOx reduction for stationary diesel engine exhaust gas and dioxin abatement for waste incineration facilities

Cited by 19 publications

References 0 publications

High-Performance Aerogel DeNO_x Catalyst: Catalytic Behavior and Kinetic Modeling

High-Performance Aerogel DeNO_x Catalyst: Catalytic Behavior and Kinetic Modeling

Solvate‐Supported Proton Transport in Zeolites

Flue Gases from Stationary Sources

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Innovative lines of SCR catalysis: NOx reduction for stationary diesel engine exhaust gas and dioxin abatement for waste incineration facilities

Cited by 19 publications

References 0 publications

High-Performance Aerogel DeNOx Catalyst: Catalytic Behavior and Kinetic Modeling

High-Performance Aerogel DeNOx Catalyst: Catalytic Behavior and Kinetic Modeling

Solvate‐Supported Proton Transport in Zeolites

Flue Gases from Stationary Sources

Contact Info

Product

Resources

About

High-Performance Aerogel DeNO_x Catalyst: Catalytic Behavior and Kinetic Modeling

High-Performance Aerogel DeNO_x Catalyst: Catalytic Behavior and Kinetic Modeling