Reduction and oxidation kinetics of Mn3O4/Mg–ZrO2 oxygen carrier particles for chemical-looping combustion

Zafar, Qamar; Abad, Alberto; Mattisson, Tobias; Gevert, Börje Sten; Strand, Michael

doi:10.1016/j.ces.2007.07.011

Cited by 143 publications

(118 citation statements)

References 25 publications

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“…The reaction proceeded through different steps including the CO adsorption on the surface, the release of oxygen from the bulk to the surface and the formation and removal of CO 2 . In this work an empirical linear model was developed for kinetic determination, in the same way as Zafar et al [42], described by Equation…”

Section: Determination Of Kinetic Parameters For Nio Reductionmentioning

confidence: 99%

“…Several works where the kinetics of reaction for the reduction with CH 4 , CO and H 2 and the oxidation with oxygen have been determined for Cu-, Ni-, Fe 2 O 3 -and Mn 3 O 4 -based oxygen carriers [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44] can be found in the literature. Most of these experimental studies have been done in a thermogravimetric analyzer.…”

Section: Introductionmentioning

confidence: 99%

“…In this case, limited information can be extracted from the reactivity data for design purposes, although they can be used to compare different oxygen carriers. Only a limited number of works were focused on the kinetics of oxygen carriers at conditions more representative of a CLC system, considering the variation of gas concentration and reactor temperature [5,[35][36][37][38][39][40][41][42][43][44].…”

Section: Introductionmentioning

confidence: 99%

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Reduction and oxidation kinetics of nickel-based oxygen-carriers for chemical-looping combustion and chemical-looping reforming

Dueso

Ortiz

Abad

et al. 2012

Chemical Engineering Journal

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168

114

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The kinetics of reduction with CH 4 , H 2 and CO and oxidation with O 2 of two NiO-based oxygen carriers prepared by impregnation, NiO18-Al and NiO21-Al, for chemicallooping combustion (CLC) and chemical-looping reforming (CLR) was investigated in this work. The experimental tests were carried out in a thermogravimetric analyzer using different reacting gas concentrations (5-20 vol. % for CH 4 , 5-50 vol. % for H 2 and CO and 5-21 vol. % for O 2 ) and temperatures (1073-1223 K). The reduction stage using both materials proceeded in two steps: a first period of high reactivity attributed to the presence of free NiO and then a low reactivity period that corresponded to NiAl 2 O 4 reduction. Therefore, the kinetic parameters for NiO and NiAl 2 O 4 reduction were determined separately for each oxygen carrier and each reacting gas. An empirical linear model was developed to describe NiO reduction. The solid conversion was a function of the fuel concentration and NiO content in the solid. The effect of temperature was low (E a ~ 5 kJ mol -1 ) although a chemical reaction rate controlled by diffusional processes was dismissed. The shrinking core model for spherical grain 2 geometry was used to obtain the kinetic parameters of the NiAl 2 O 4 reduction working with both NiO-based oxygen carriers. Chemical reaction control was assumed for NiO18-Al whereas diffusion through product layer was also considered when NiO21-Al was used as oxygen carrier. 82-472 kJ mol -1 activation energies were obtained with NiO18-Al particles. The activation energies were 237 and 373 kJ mol -1 for the kinetic constant and 200-281 kJ mol -1 for the diffusion coefficient, respectively, in the case of NiO21-Al oxygen carrier. Reduction reaction of NiO21-Al with CO was extremely slow and the kinetic parameters were obtained for comparison purposes with chemical control of the reaction rate. In this case, the reaction order was 1 and the activation energy 89 kJ mol -1 . The combined model for consecutive reduction of NiO and NiAl 2 O 4 in the NiO18-Al particles with the kinetic parameters obtained in this work predicted adequately the experimental results. The oxidation step of both oxygen carriers was fast and complete until reaching the initial condition. An empiric linear model, which assumes a linear relation between time and conversion, was developed to determine the kinetics of Ni oxidation. The reaction order of oxidation was about 0.8 for NiO18-Al and NiO21-Al and the activation energies were low, 22 kJ mol -1 in both cases. 

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Section: Determination Of Kinetic Parameters For Nio Reductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Reduction and oxidation kinetics of nickel-based oxygen-carriers for chemical-looping combustion and chemical-looping reforming

Dueso

Ortiz

Abad

et al. 2012

Chemical Engineering Journal

Self Cite

168

114

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“…Rashidi et al (2013b) found only a small induction period in the reduction of unsupported nickel oxide with methane, and neglected it in the modified grain model for spherical grain geometry. However, an induction period was indeed observed during the reduction of iron ore, Ni-based oxygen carrier and LaMnO 3 perovskite (Nasr and Plucknett, 2014;Sarshar et al, 2013;Zafar et al, 2007). Sarshar and Kaliaguine (2013) found that both SCM and NNGM yield poor fits of the reduction kinetic data, and the introduction of an induction time in kinetic model will improve the valid estimation.…”

Section: Introductionmentioning

confidence: 99%

Reduction kinetics of lanthanum ferrite perovskite for the production of synthesis gas by chemical-looping methane reforming

Dai

Cheng

et al. 2016

Chemical Engineering Science

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“…The kinetics from Garcia-Labiano et al [28] and Zafar et al [29] have been selected, including the expected influence of diffusion limitations inside the particles, which have been determined with the particle model [30] and are shown in Table 1. The influence of the reaction rate in large packed bed reactors is limited to the shape of the reaction front, which covers only a small part of the reactor.…”

Section: Packed Bed Reactor Model For Clc Reactorsmentioning

confidence: 99%

Energy analysis of two stage packed-bed chemical looping combustion configurations for integrated gasification combined cycles

Hamers

Romano

Spallina

et al. 2015

Energy

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Reduction and oxidation kinetics of Mn3O4/Mg–ZrO2 oxygen carrier particles for chemical-looping combustion

Cited by 143 publications

References 25 publications

Reduction and oxidation kinetics of nickel-based oxygen-carriers for chemical-looping combustion and chemical-looping reforming

Reduction and oxidation kinetics of nickel-based oxygen-carriers for chemical-looping combustion and chemical-looping reforming

Reduction kinetics of lanthanum ferrite perovskite for the production of synthesis gas by chemical-looping methane reforming

Energy analysis of two stage packed-bed chemical looping combustion configurations for integrated gasification combined cycles

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