Deactivation of the Vanadia Catalyst in the Selective Catalytic Reduction Process

Chen, J. P.; Buzanowski, Marek A.; Yang, Rongwei; Cichanowicz, J. E.

doi:10.1080/10473289.1990.10466793

Cited by 126 publications

(86 citation statements)

References 7 publications

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“…The most interesting result is that calcium appears to increase catalyst activity, something that contradicts the results of previous research (Chen, Buzanowski et al 1990;Chen and Yang 1990). At the present time we have no logical explanation for this phenomenon.…”

Section: Discussion Of the Catalyst Poisoning Studycontrasting

confidence: 56%

NOx Control Options and Integration for US Coal Fired Boilers

Bockelie¹,

Davis²,

Linjewile³

et al. 2003

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This is the fourteenth Quarterly Technical Report for DOE Cooperative Agreement No: DE-FC26-00NT40753. The goal of the project is to develop cost effective analysis tools and techniques for demonstrating and evaluating low NO x control strategies and their possible impact on boiler performance for boilers firing US coals. The Electric Power Research Institute (EPRI) is providing co-funding for this program. Using the initial CFD baseline modeling of the Gavin Station and the plant corrosion maps, six boiler locations for the corrosion probes were identified and access ports have been installed. Preliminary corrosion data obtained appear consistent and believable.In situ, spectroscopic experiments at BYU reported in part last quarter were completed. New reactor tubes have been made for BYU's CCR that allow for testing smaller amounts of catalyst and thus increasing space velocity; monolith catalysts have been cut and a small reactor that can accommodate these pieces for testing is in its final stages of construction. A poisoning study on Ca-poisoned catalysts was begun this quarter. A possible site for a biomass co-firing test of the slipstream reactor was visited this quarter. The slipstream reactor at Rockport required repair and refurbishment, and will be re-started in the next quarter. This report describes the final results of an experimental project at Brown University on the fundamentals of ammonia / fly ash interactions with relevance to the operation of advanced NO x control technologies such as selective catalytic reduction. The Brown task focused on the measurement of ammonia adsorption isotherms on commercial fly ash samples subjected to a variety of treatments and on the chemistry of dry and semi-dry ammonia removal processes.iii Table of Our program contains five major technical tasks:• evaluation of Rich Reagent Injection (RRI) for in-furnace NO x control;• demonstration of RRI technologies in full-scale field tests at utility boilers;• impacts of combustion modifications (including corrosion and soot);• ammonia adsorption / removal from fly ash; and • SCR catalyst testing.To date, good progress is being made on the overall program. We have seen considerable interest from industry in the program due to our successful initial field tests of the RRI technology and the corrosion monitor.During the last three months, our accomplishments include the following:• Using the initial CFD baseline modeling of the Gavin Station and the plant corrosion maps, six boiler locations for the corrosion probes were identified and access ports have been installed.• One probe has been collecting data for more than three months and two others have been in service for more than two months; preliminary corrosion data obtained appear consistent and believable.• In situ, spectroscopic experiments at BYU reported in part last quarter were completed; the most significant finding of these investigations was a consistent indication that vanadium does not sulfate during SCR reaction in the presence of gas-phase SO 2 whil...

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Section: Discussion Of the Catalyst Poisoning Studycontrasting

confidence: 56%

NOx Control Options and Integration for US Coal Fired Boilers

Bockelie¹,

Davis²,

Linjewile³

et al. 2003

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“…The apparent activation energy of 40 kJ/mol for the fresh catalysts indicates mass transfer limitations since the intrinsic activation energy is around 85 kJ/mol. We have found one other paper [41] reporting the gradients in a 3.45% V 2 O 5 /TiO 2 catalyst measured at 300 °C. The concentration of NO at the centre of the fresh catalyst was reported to be 20% of the value at the monolith wall (internal gradient, wall thickness of 0.38 mm).…”

Section: Discussionmentioning

confidence: 99%

Deactivation and Characterization of SCR Catalysts Used in Municipal Waste Incineration Applications

Brandin

Odenbrand

2017

Catal Lett

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changes in surface area (8% decrease in BET surface area over 2311 h) and pore structure were small, while the change in activity was considerable. The apparent pre-exponential factor was 1.63 × 10 5 (1/min) in the most deactivated catalyst, compared to 2.65 × 10 6 (1/min) in the fresh catalyst, i.e. a reduction of 94%. The apparent activation energy for the fresh catalyst was 40 kJ/mol, decreasing to 27 kJ/mol with increasing deactivation. Characterization showed that catalytic poisoning is mainly due to decreased acidity of the catalyst caused due to increasing amounts of Na and K.Abstract Catalysts used for selective catalytic reduction were deactivated for various times in a slipstream from a municipal solid waste incineration plant and then characterized. The activity for NO reduction with NH 3 was measured. The Brunauer-Emmett-Teller surface areas were determined by N 2 adsorption from which the pore size distributions in the mesopore region were obtained. Micropore areas and volumes were also obtained. The composition of fresh and deactivated catalysts as well as fly ash was determined by atomic absorption spectroscopy and scanning electron microscopy with energy dispersive X-ray analysis. The

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“…[5]. Innerhalb der Versuchszeiten konnte eine Aktivitätsabnahme in Verbindung mit einer erhöhten P-Konzentration festgestellt werden, die aufgrund der unveränderten physikalischen Eigenschaften eine chemische Vergiftung der Katalysatoren nahe legt.…”

Section: Verbrennungsversucheunclassified