Alkali resistant Cu/zeolite deNOx catalysts for flue gas cleaning in biomass fired applications

Putluru, Siva Sankar Reddy; Riisager, Anders; Fehrmann, Rasmus

doi:10.1016/j.apcatb.2010.09.015

Cited by 83 publications

(64 citation statements)

References 33 publications

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“…For the Cu-HMOR sample, an additional desorption peak at about 600 K was observed, resulting from the decomposition of a copper ammonia complex that was formed during ammonia adsorption. 36,37 Together with the 1 H MAS NMR result in Figure 3, the total amount of the Brønsted acidic sites on the Cu-HMOR catalyst was estimated to be 0.31 mmol/g: 0.20 mmol/g in the 8-MR channels and 0.11 mmol/g in the 12-MR channels. These results further demonstrate that the copper cations were almost equally exchanged with the protons in both 8-MR and 12-MR channels.…”

Section: Resultsmentioning

confidence: 99%

Dimethyl Ether Carbonylation to Methyl Acetate over Nanosized Mordenites

Xue

Huang

Ditzel³

et al. 2013

Ind. Eng. Chem. Res.

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Nanosized mordenites were found to show significantly enhanced reaction efficiency in dimethyl ether (DME) carbonylation to methyl acetate (MA) because of a greatly facilitated diffusion process. Copper incorporation into the channels of the nanosized mordenites further promoted the reaction rate, selectivity, and stability. Moreover, upon the addition of a small amount of H 2 (5−19 vol %) to the feed gas, deactivation was suppressed during DME carbonylation, whereas the catalyst stability and rate of formation of MA increased.

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Section: Resultsmentioning

confidence: 99%

Dimethyl Ether Carbonylation to Methyl Acetate over Nanosized Mordenites

Xue

Huang

Ditzel³

et al. 2013

Ind. Eng. Chem. Res.

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“…The element composition of various fuels and ash formed in industrial biomass fired power plants, have recently been reported [8][9][10][11]. Studies show a significant increase in the quantity of alkali and alkaline-earth elements (K, Na, Mg, Ca), phosphorous and chlorine in the flue gas produced from biomass-based fuels compared to coal [9].…”

Section: Introductionmentioning

confidence: 99%

“…Potential alternatives to the vanadium-based SCR systems are supported Fe and Cu oxide catalysts [4,6,11]. Ideally, the support should be thermally stable, have high surface area and be strongly acidic in order to attract alkali metals and thus protect the active metal sites for alkali poisoning.…”

Section: Introductionmentioning

confidence: 99%

“…Chemical deactivation of catalysts by deposition of alkali poisons have been investigated with different methods, such as wet-chemical impregnation [5,[10][11][12], aerosol exposure [13] and flue gas exposure in power plants [8,14]. Usually the wet-chemical impregnation method is preferred to screen the catalysts, since it is fast and allows the poison level of deactivation to be controlled by the amount of poison added.…”

Section: Introductionmentioning

confidence: 99%

“…Combustion of natural gas and fossil fuels such as coal leads to a relatively clean flue gas, whereas combustion of, e.g. municipal waste or biomass, often contain species that can lead to deactivation of the traditional vanadiatitania-based SCR catalyst [7][8][9][10][11][12][13][14][15][16][17]. Biomass combustion result in formation of particulates with high concentration in the submicrometer range.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Alkali resistivity of Cu based selective catalytic reduction catalysts: Potassium chloride aerosol exposure and activity measurements

Putluru

Jensen

Riisager

et al. 2012

Catalysis Communications

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A “Smart” Hollandite DeNO_x Catalyst: Self‐Protection against Alkali Poisoning

Wen²,

et al. 2012

Angewandte Chemie

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Global warming, caused by an increase in atmospheric CO 2 concentrations, and limited fossil-fuel resources have stimulated the search for environmentally sustainable energy sources with zero or low CO 2 emission. [1] The use of biomass as a CO 2 -neutral fuel has drawn widespread attention, since biomass as part of the global carbon ecocycle is an increasingly important energy resource. [2] An associated issue, which is often encountered in the control of NO x emissions from the alkali-rich stack gas of power plants (co-)fuelled by biomass, is the severe deactivation of conventional V 2 O 5 -WO 3 /TiO 2 catalysts in the selective catalytic reduction of NO by NH 3 (NH 3 -SCR). [3,4] This deactivation is predominately caused by the strong interaction of alkali-metal ions with catalytically active sites. [4][5][6][7][8][9][10][11] For example, Zheng et al. [8] proposed a deactivation mechanism by proton exchange at catalytically active Brønsted acid sites with alkali-metal ions. The exchange reactions occur readily at normal NH 3 -SCR operating temperatures because alkali species, such as KCl and K 2 SO 4 , are mobile in view of their low Tamman temperatures (T Tam ). [12] On the basis of this deactivation mechanism, a possible approach to the development of an alkali-resistant catalyst is to increase the number of catalytically active sites and "alkaliactive" sites (for trapping alkalis), for example, by using a support with the property of high or super acidity or by increasing the concentration of active elements. [9-11, 13, 14] However, this approach can not completely alleviate alkali poisoning because, to a great extent, alkali-metal ions and reactants compete for the same sites. Therefore, the development of a highly alkali resistant catalyst remains a great challenge. Herein we describe the successful development of a hollandite manganese oxide (HMO) catalyst with separate catalytically active sites (for NH 3 -SCR) and alkali-active sites (for alkali trapping). With the combined action of the two types of active sites, this bifunctional HMO catalyst not only protects catalytically active sites against alkali poisoning, but also preserves high catalytic activity at the original level until all the alkali-active sites are occupied.We used K + as a probe to clearly identify the catalytically active sites of HMO in NH 3 -SCR reactions, as K + is a wellknown catalyst poison. [7][8][9][10][11] Figure 1 shows the catalytic activity of HMO with different K + loadings in NH 3 -SCR reactions at 350 8C as expressed in terms of the rate constant for the conversion of NO. [9][10][11] The K + loading had almost no influence on the catalytic activity of HMO, and all HMO catalysts tested exhibited almost the same activity.For reference, a conventional deNO x catalyst (V 2 O 5 -WO 3 / TiO 2 ) with different K + loadings was also tested in the NH 3 -SCR reactions under the same conditions (Figure 1). As expected, the V 2 O 5 -WO 3 /TiO 2 catalyst exhibited rather poor alkali resistance and underwent severe and continuous d...

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Alkali resistant Cu/zeolite deNOx catalysts for flue gas cleaning in biomass fired applications

Cited by 83 publications

References 33 publications

Dimethyl Ether Carbonylation to Methyl Acetate over Nanosized Mordenites

Dimethyl Ether Carbonylation to Methyl Acetate over Nanosized Mordenites

Alkali resistivity of Cu based selective catalytic reduction catalysts: Potassium chloride aerosol exposure and activity measurements

A “Smart” Hollandite DeNO_x Catalyst: Self‐Protection against Alkali Poisoning

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Alkali resistant Cu/zeolite deNOx catalysts for flue gas cleaning in biomass fired applications

Cited by 83 publications

References 33 publications

Dimethyl Ether Carbonylation to Methyl Acetate over Nanosized Mordenites

Dimethyl Ether Carbonylation to Methyl Acetate over Nanosized Mordenites

Alkali resistivity of Cu based selective catalytic reduction catalysts: Potassium chloride aerosol exposure and activity measurements

A “Smart” Hollandite DeNOx Catalyst: Self‐Protection against Alkali Poisoning

Contact Info

Product

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A “Smart” Hollandite DeNO_x Catalyst: Self‐Protection against Alkali Poisoning