Determination of intrinsic rate constants of the CaO–CO2 reaction

Sun, Ping; Grace, John R.; Lim, C. Jim; Anthony, Edward J.

doi:10.1016/j.ces.2007.08.055

Cited by 224 publications

(230 citation statements)

References 16 publications

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“…The conversion reached by the end of the second carbonation for the middle CO2 partial pressure (10 kPa) exhibited the higher drop in value from the respective one in the first carbonation and when compared with the final conversions of the second carbonation steps at 5 and 15 kPa of CO2. Similar to the present 'dry' macro-scale final carbonation conversions, Sun et al (2008) noticed a better performance of carbonations when partial pressures of CO2 smaller than 10 kPa were used, whereas for PCO2 > 10 kPa the respective performance was limited. Experimental 'dry' carbonation conversions were extremely well reproduced from the iterative method described earlier based on the hypothesis of the Jander (3D) diffusion equation.…”

Section: Macro-scalesupporting

confidence: 64%

“…This might be due to the fact that the apparent carbonation activation energy in that earlier work was produced by using the power law kinetic equation (Sun et al 2008) when the present one was based on the Jander (3D) diffusion equation, resulting in more than twice as large values between the first and second mechanism. Additionally, Urbanovici, Popescu, and Segal (1999) found that a ratio of 2.7 was obtained in the case of isothermal Mg(OH)2 dehydration when the power law equation was used compared to the Jander (3D) diffusion equation.…”

Section: Micro-scalementioning

confidence: 88%

“…Interestingly enough, at the 15 kPa carbonation, the required activation energy in both the first and second carbonations was set in the lowest value scale, compared with those at 5 and 10 kPa CO2. In previous works (Sun et al 2008), much lower values of the carbonation at 5 kPa CO2 were calculated (26 kJ mol…”

Section: Micro-scalementioning

confidence: 99%

“…At present, there is an intense interest in chemical looping systems (Blamey et al 2010;Li et al 2008) which haveso far been mainly developed for the combustion industry and applied to fluidised bed technology (Chen,Grace,and Lim 2011;Sun et al 2008). Lyon and Cole (2000) suggested unmixed combustion which has been lately deployed in the chemical looping technology (Dupont et al 2007;Pimenidou et al 2010a).…”

Section: Introductionmentioning

confidence: 99%

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Dolomite study forin situCO₂capture for chemical looping reforming

Pimenidou

Dupont

2013

International Journal of Ambient Energy

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The non-isothermal kinetic and thermal behaviour of a naturally formed dolomite in conditions that approach in situ CO2 capture in chemical looping reforming, were investigated. The performance of this dolomite was studied at micro-scale in 'dry' conditions, as well as at macro-scale in 'dry' and 'wet' conditions to investigate the effects of scale (3 mg, 2.5 g), partial pressures of CO 2 (< 15 kPa) and steam, and deactivation upon limited cycling. The carbonation and calcination kinetics were modelled using an improved iterative Coats-Redfern method. Increasing CO 2 partial pressures on the 'dry' macroscale exacerbated the experimental carbonation conversions in an inversely proportional trend when compared with those at micro-scale. The presence of steam had a positive effect on CO 2 chemisorption. Steam had a negligible influence on the calcination activation energies. The activation energies of carbonation were increased for the experiments at the highest CO 2 partial pressures under wet conditions.

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Section: Macro-scalesupporting

confidence: 64%

Section: Micro-scalementioning

confidence: 88%

Section: Micro-scalementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dolomite study forin situCO₂capture for chemical looping reforming

Pimenidou

Dupont

2013

International Journal of Ambient Energy

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“…Also, Sun et al studied the kinetics of CaO+CO 2 reaction using the grain model 9 . They found that the intrinsic rate has a variable order with respect to CO 2 partial pressure, changing from fi rst order to zero order for CO 2 partial pressures greater than 10 kPa.…”

mentioning

confidence: 99%

Kinetic study of CO₂ reaction with CaO by a modified random pore model

Nouri

Ebrahim

2016

Polish Journal of Chemical Technology

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In this work, a modifi ed random pore model was developed to study the kinetics of the carbonation reaction of CaO. Pore size distributions of the CaO pellets were measured by nitrogen adsorption and mercury porosimetry methods. The experiments were carried out in a thermogravimeter at different isothermal temperatures and CO 2 partial pressures. A fractional concentration dependency function showed the best accuracy for predicting the intrinsic rate of reaction. The activation energy was determined as 11 kcal/mole between 550-700 o C. The effect of product layer formation was also taken into account by using the variable product layer diffusivity. Also, the model was successfully predicted the natural lime carbonation reaction data extracted from the literature.

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