Kinetics of the conversion of NO to N2 during the oxidation of iron particles by NO in a hot fluidised bed

Hayhurst, A.N.; Ninomiya, Yoshihiko

doi:10.1016/s0009-2509(98)00009-8

Cited by 43 publications

(44 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This phenomenon is described in the literature [12,15]. According to the explanation provided in the literature, the oxidation of iron in the presence of oxygen (a later stage) is controlled by the diffusion of iron ions from the unreacted metal core to the external surface of the metal oxide.…”

Section: Correction Factor That Accounts For the Oxygen Influencementioning

confidence: 91%

“…Lissianski et al [9,23,30], who used a pilotscale combustion chamber, and Su et al [24], who used a laboratory-scale facility, both focused on the use of iron or iron oxide in pulverized coal combustion chambers. Fennel et al [12,17], who used the TGA method, Hayhurst and Lawrence [19], who used a laboratory-scale FB reactor, and Hayhurst and Ninomiya [15], who used a laboratoryscale FB reactor, suggested the use of iron as a de-NO x agent in fluidized-bed combustors. Although some necessary model simplifications have been adopted, the results obtained in this work can be assumed to be useful for the application of iron as the active species for NO x removal from grate combustion chambers.…”

Section: Application Of Iron In the De-nox Process: A Brief Analysismentioning

confidence: 99%

“…It should be noted that complete oxidation of Fe to Fe 2 O 3 is possible for temperature range of 973-1173 K and NO concentration lower than 500 ppmv [15]. Table 1 shows calculation of Gibbs free energy.…”

Section: Introductionmentioning

confidence: 99%

“…Additionally, the kinetic coefficients of the chemical reaction between NO and Fe have been determined as a function of temperature [9,13,15,17,19,23]. Recently, Fennell et al [12] reported a study of the latter stages of reaction (1), when the process has been controlled by the diffusion of iron ions through an oxide layer around the iron particle.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Investigations of the reduction of NO to N2 by reaction with Fe under fuel-rich and oxidative atmosphere

Lasek

2014

Heat Mass Transfer

View full text Add to dashboard Cite

The limitation of nitrogen oxides (NO x ) emissions from stationary combustion chambers is still an important issue in the field of the natural environment protection. This paper describes the reduction of NO x in the presence of iron. A few new aspects of research describing the utilization of iron as an additive that influences NO x reduction at high temperatures are presented. In particular, the influence of the excess air number (k) on the NO x removal efficiency in the presence of Armco iron was determined. A [50 % increase in the efficiency was achieved at k = 0.6. The research was conducted using N 2 / NO mixed with a flue gas from carbon monoxide combustion. In addition, a correction factor (Arrhenius-type empirical equation) was determined, which enabled the calculation of the oxygen influence on the inhibition of the de-NO x reaction in the presence of iron. The NO x reduction was also tested using bearing steel samples. Finally, the use of iron in de-NO x processes under different combustion conditions is briefly reviewed and analyzed.

show abstract

Section: Correction Factor That Accounts For the Oxygen Influencementioning

confidence: 91%

Section: Application Of Iron In the De-nox Process: A Brief Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigations of the reduction of NO to N2 by reaction with Fe under fuel-rich and oxidative atmosphere

Lasek

2014

Heat Mass Transfer

View full text Add to dashboard Cite

show abstract

“…[3][4][5][6][7][8] Hayhurst and Lawrence 3 studied the kinetics for NO x (NO and N 2 O) removal at temperatures of 973 and 1173 K in a fluidized bed using a 139 -400 m ZVI particle for influent NO concentration of 1350 -1470 ppm. They pointed out that the ZVI and NO interaction is a redox reaction with the following possibilities:…”

Section: Introductionmentioning

confidence: 99%

Mechanisms of NO_x Removal from Flue Gas by Zero Valent Iron

Chen

Cheng

Chang

et al. 2006

Journal of the Air & Waste Management Association

View full text Add to dashboard Cite

Chemical reaction between nitric oxide (NO) and zero valent iron (ZVI) was studied in a packed-bed column process with high temperatures based on ZVI strong reducing abilities. For six controlled temperatures of 523-773 K and 400 ppm of NO (typical flue gas temperature and concentration), under short empty bed contact time ([EBCT] 0.0226 -0.0679 sec), NO was completely removed for temperature of 573-773 K but not for 523 K. Breakthrough curves were conducted for the five working temperatures, and the results indicated that NO reductions by ZVI were varied from 2 to 26.7 mg NO/g ZVI. Higher temperature and longer EBCT achieved better NO removal efficiency. X-ray diffraction (XRD) and electron spectroscopy for chemical analysis (ESCA) were conducted to analyze the crystal structure and oxidation state of the reacted ZVI. Three layers of iron species were detected by XRD: ZVI, Fe 3 O 4 , and Fe 2 O 3 . ZVI was the most prevalent species, and Fe 3 O 4 and Fe 2 O 3 were less from the XRD analysis. By ESCA, the oxidation state on the reacted ZVI surface was determined, and the species was identified as Fe 2 O 3 , which is the most oxidizing species for iron. Therefore, three layers from the ZVI core to the ZVI surface can be identified: ZVI, Fe 3 O 4 , and Fe 2 O 3 . Combining the results from XRD and ESCA, the mechanisms for ZVI and NO can be proposed as two consecutive reactions from lower oxidation state (ZVI) in the core to higher oxidation state on the iron surface (Fe 2 O 3 ):andBecause there was only Ͻ5% ZVI used to remove NO comparing to theoretical ZVI used based on the proposed stoichiometry, it can be concluded that the heterogeneous reaction only occurred on the ZVI surface instead of on bulk of the ZVI.

show abstract

Study on the Effects of Fe Doping on C‐ZFe Catalyst for Catalytic Removal of NO from the Low‐Temperature Flue Gas

Cao,

Zhang,

Guo

et al. 2024

ChemistrySelect

View full text Add to dashboard Cite

The denitrification efficiency of carbon‐based zero valent iron catalyst (C‐ZFe) for low‐temperature selective catalytic reduction (SCR) (<140°C) highly depends on the structural species of iron oxide (FexOy) and the physicochemical properties of the catalyst. In the study, we investigated the main factors affecting the low‐temperature denitrification efficiency of C‐ZFe such as temperature, iron content and O2. The results showed that the average NOX conversion was 72.6 % at 135°C when the space velocity was 459 h−1 and the mass ratio of carbon to iron was 15 % to 85 %. The surface morphology and structure of C‐ZFe were characterized by the surface area and pore size distribution measurements, X‐ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and X‐ray photoelectron spectroscopy (XPS). The results indicated that the iron on the catalyst surface was oxidized by O2 to Fe2O3, which could retain NO and then formed intermediate products. NO entered the mesoporous structure along C‐ZFe surface and proceeded a catalytic reduction reaction with the adjacent carbon.

show abstract

Kinetics of the conversion of NO to N2 during the oxidation of iron particles by NO in a hot fluidised bed

Cited by 43 publications

References 10 publications

Investigations of the reduction of NO to N2 by reaction with Fe under fuel-rich and oxidative atmosphere

Investigations of the reduction of NO to N2 by reaction with Fe under fuel-rich and oxidative atmosphere

Mechanisms of NO_x Removal from Flue Gas by Zero Valent Iron

Study on the Effects of Fe Doping on C‐ZFe Catalyst for Catalytic Removal of NO from the Low‐Temperature Flue Gas

Contact Info

Product

Resources

About

Kinetics of the conversion of NO to N2 during the oxidation of iron particles by NO in a hot fluidised bed

Cited by 43 publications

References 10 publications

Investigations of the reduction of NO to N2 by reaction with Fe under fuel-rich and oxidative atmosphere

Investigations of the reduction of NO to N2 by reaction with Fe under fuel-rich and oxidative atmosphere

Mechanisms of NOx Removal from Flue Gas by Zero Valent Iron

Study on the Effects of Fe Doping on C‐ZFe Catalyst for Catalytic Removal of NO from the Low‐Temperature Flue Gas

Contact Info

Product

Resources

About

Mechanisms of NO_x Removal from Flue Gas by Zero Valent Iron