Model based scale-up study of the calcium looping process

Ylätalo, Jaakko; Ritvanen, Jouni; Tynjälä, Tero; Hyppänen, Timo

doi:10.1016/j.fuel.2013.07.036

Cited by 34 publications

(40 citation statements)

References 20 publications

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“…Firstly, the high temperature required to achieve a complete regeneration of the sorbent in short residence times since calcination has to be carried out under the high CO 2 partial pressure calciner environment [11][12][13][14]. Such high temperatures would be attained by oxy-combustion in order to avoid CO 2 dilution, which entails a marked energy penalty to the process due to fuel consumption and additional CO 2 production [9,10,[14][15][16][17][18].…”

Section: The Partially Carbonated Particles Are Then Transported Intomentioning

confidence: 99%

“…The second inconvenient is the progressive deactivation of the sorbent along the successive carb/calc cycles that makes necessary to periodically introduce a fresh limestone makeup into the calciner. CaO deactivation may occur due to the screening effect of external agents such as ash or SO 2 produced during oxycombustion, which leads to the irreversible sulphation of the CaO particles [9,13,19,20]. Yet, deactivation is mostly caused by the drastic loss of surface area of the CaO grains when calcination takes place under high CO 2 partial pressure and high temperatures, which enhances aggregation and subsequent sintering of the nascent CaO nanocrystals during the CaCO 3 /CaO transformation [21].…”

Section: The Partially Carbonated Particles Are Then Transported Intomentioning

confidence: 99%

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Effect of dolomite decomposition under CO₂ on its multicycle CO₂ capture behaviour under calcium looping conditions

Martos

Valverde

Jiménez

et al. 2016

Phys. Chem. Chem. Phys.

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One of the main drawbacks that hinder the industrial competitiveness of the Calcium Looping (CaL) process for CO 2 capture is the high temperatures (~930-950ºC) needed in practice to attain full calcination of limestone under a high CO 2 partial pressure environment for short residence times as required in practice. In this work, the multicycle CO 2 capture performance of dolomite and limestone is analysed under realistic CaL conditions and using a reduced calcination temperature of 900ºC, which would serve to mitigate the energy penalty caused by integrating the CaL process into fossil fuel fired power plants. The results show that the fundamental mechanism of dolomite decomposition under CO 2 has a main influence on its superior performance compared to limestone. The inert MgO grains resulting from dolomite decomposition help preserving a nanocrystalline CaO structure wherein carbonation in the solid-state diffusion controlled phase is promoted. The major role played by dolomite decomposition mechanism under CO 2 is clearly demonstrated by the multicycle CaO conversion behaviour observed for samples decomposed at different preheating rates. Limestone decomposition at slow heating rates yields a highly crystalline and poorly reactive CaCO 3 structure that requires long periods to fully decarbonate and shows a severely reduced capture capacity in subsequent cycles. On the other hand, the nascent CaCO 3 produced after dolomite half-decomposition consists of nanosized crystals with a fast decarbonation kinetics regardless of the preheating rate, thus fully decomposing from the very first cycle at a reduced calcination temperature into a CaO skeleton with enhanced reactivity as compared to limestone derived CaO.

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Section: The Partially Carbonated Particles Are Then Transported Intomentioning

confidence: 99%

Section: The Partially Carbonated Particles Are Then Transported Intomentioning

confidence: 99%

Effect of dolomite decomposition under CO₂ on its multicycle CO₂ capture behaviour under calcium looping conditions

Martos

Valverde

Jiménez

et al. 2016

Phys. Chem. Chem. Phys.

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“…Using the multicyclic TGA results reported in [34,35,42], we develop below a modified carbonator model built upon the model proposed by Alonso et al [18]. 10 The main novelty of our model is that carbonation in the diffusion controlled phase will be considered to predict the carbonation efficiency. pressure.…”

Section: Kinetic Modelmentioning

confidence: 99%

“…Efficient gas-solid contact and heat/mass transfer would be ensured by the use of circulating fluidizedbed reactors (CBF). CFBs are typically operated at atmospheric pressure under the fast fluidization regime, with gas velocities of the order of 5-10 m/s [9,10]. The partially carbonated particles are driven into a second fluidized bed reactor (calciner), where CaO is regenerated by calcination under high temperatures and necessarily high CO 2 concentration [11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

A new model of the carbonator reactor in the calcium looping technology for post-combustion CO2 capture

Ortíz

Chacartegui

Becerra

et al. 2015

Fuel

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“…Once needed, the reactants are circulated into a carbonator reactor, where the energy stored in chemical form is released through the reverse reaction (carbonation). Efficient gas-solid contact and heat/mass transfer in the calciner and carbonator reactors could be ensured by the use of circulating fluidized-beds (CFB), which are operated under the fast fluidization regime with gas velocities of the order of 5-10 m/s [26,27]. An advantage of this technology ahead of its incorporation into the market is the proven efficiency and durability of such type of fluidized bed reactors.…”

Section: Introductionmentioning

confidence: 99%

Thermochemical energy storage of concentrated solar power by integration of the calcium looping process and a CO2 power cycle

et al. 2016

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Energy storage is the main challenge for a deep penetration of renewable energies into the grid to overcome their intrinsic variability. Thus, the commercial expansion of renewable energy, particularly wind and solar, at large scale depends crucially on the development of cheap, efficient and non-toxic energy storage systems enabling to supply more flexibility to the grid. The Ca-Looping (CaL) process, based upon the reversible carbonation/calcination of CaO, is one of the most promising technologies for thermochemical energy storage (TCES), which offers a high potential for the long-term storage of energy with relatively small storage volume. This manuscript explores the use of the CaL process to store Concentrated Solar Power (CSP). A CSP-CaL integration scheme is proposed mainly characterized by the use of a CO 2 closed loop for the CaL cycle and power production, which provides heat decoupled from the solar source and temperatures well above the ~550ºC limit that poses the use of molten salts currently used to store energy as sensible heat. The proposed CSP-CaL integration leads to high values of plant global efficiency (of around 45-46%) with a storage capacity that allows for long time gaps between load and discharge. Moreover, the use of environmentally benign, abundantly available and cheap raw materials such as natural limestone would mark a milestone on the road towards the industrial competitiveness of CSP.

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Model based scale-up study of the calcium looping process

Cited by 34 publications

References 20 publications

Effect of dolomite decomposition under CO₂ on its multicycle CO₂ capture behaviour under calcium looping conditions

Effect of dolomite decomposition under CO₂ on its multicycle CO₂ capture behaviour under calcium looping conditions

A new model of the carbonator reactor in the calcium looping technology for post-combustion CO2 capture

Thermochemical energy storage of concentrated solar power by integration of the calcium looping process and a CO2 power cycle

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Model based scale-up study of the calcium looping process

Cited by 34 publications

References 20 publications

Effect of dolomite decomposition under CO2 on its multicycle CO2 capture behaviour under calcium looping conditions

Effect of dolomite decomposition under CO2 on its multicycle CO2 capture behaviour under calcium looping conditions

A new model of the carbonator reactor in the calcium looping technology for post-combustion CO2 capture

Thermochemical energy storage of concentrated solar power by integration of the calcium looping process and a CO2 power cycle

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Effect of dolomite decomposition under CO₂ on its multicycle CO₂ capture behaviour under calcium looping conditions

Effect of dolomite decomposition under CO₂ on its multicycle CO₂ capture behaviour under calcium looping conditions