A fluidized-bed combustion process with inherent CO2 separation; application of chemical-looping combustion

Lyngfelt, Anders; Leckner, Bo G; Mattisson, Tobias

doi:10.1016/s0009-2509(01)00007-0

Cited by 946 publications

(734 citation statements)

References 13 publications

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“…CLC is mostly carried out in two interconnected fluidized-bed reactors with the OC in the form of particles circulating in between [1][2][3][4][5][6][7]. Alternatively, a rotary reactor consisting of a large number of micro-channels was proposed in previous studies [8][9][10][11][12].…”

Section: Introductionmentioning

confidence: 99%

Design of a rotary reactor for chemical-looping combustion. Part 2: Comparison of copper-, nickel-, and iron-based oxygen carriers

Zhao

Ghoniem

2014

Fuel

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Chemical-looping combustion (CLC) is a novel and promising option for several applications including carbon capture (CC), fuel reforming, H 2 generation, etc. Previous studies demonstrated the feasibility of performing CLC in a novel rotary design with micro-channel structures. Part 1 of this series studied the fundamentals of the reactor design and proposed a comprehensive design procedure, enabling a systematic methodology of designing and evaluating the rotary CLC reactor with different OCs and operating conditions. This paper presents the application of the methodology to the designs with three commonly used OCs, i.e., copper, nickel, and iron.The physical properties and the reactivities of the three OCs are compared at operating conditions suitable for the rotary CLC. Nickel has the highest reduction rate, but relatively slow oxidation reactivity while the iron reduction rate is most sensitive to the fuel concentration. The design parameters and the operating conditions for the three OCs are selected, following the  Corresponding author. Tel.: +1 617 253 2295. E-mail address: ghoniem@mit.edu (A.F. Ghoniem) 2 strategies proposed in Part 1, and the performances are evaluated using a one-dimensional plugflow model developed previously. The simulations show that for all OCs, complete fuel conversion and high carbon separation efficiency can be achieved at periodic stationary state with reasonable operational stabilities. The nickel-based design includes the smallest dimensions because of its fast reduction rate. The operation of nickel case is mainly limited to the slow oxidation rate, and hence a relatively large share of air sector is used. The iron-based design has the largest size, due to its slow reduction reactivity near the exit or in the fuel purge sector where the fuel concentration is low. The gas flow temperature increases monotonically for all the cases, and is mainly determined by the solid temperature. In the periodic state, the local temperature variation is within 40K and the thermal distortion is limited. The design of the rotary CLC is also scaled to different pressures and inlet temperatures. The method of scaling is discussed and desirable operational performances are obtained.

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Section: Introductionmentioning

confidence: 99%

Design of a rotary reactor for chemical-looping combustion. Part 2: Comparison of copper-, nickel-, and iron-based oxygen carriers

Zhao

Ghoniem

2014

Fuel

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“…CLC is based on the transfer of the oxygen from air to the fuel by means of a solid oxygen carrier. Different configurations have been proposed for CLC: interconnected fluidized beds [5] and fixed alternating beds [6,7].…”

Section: Introductionmentioning

confidence: 99%

“…Recirculation of CO 2 could be advantageous from an energetic point of view. exits the fuel reactor and is oxidized with air in the air reactor according to reaction (5 …”

Section: Introductionmentioning

confidence: 99%

Relevance of the coal rank on the performance of the in situ gasification chemical-looping combustion

Cuadrat

Abad

Gayán

et al. 2012

Chemical Engineering Journal

102

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In this work the CLC process for solid fuels using ilmenite as oxygen carrier was evaluated in a continuous CLC unit. In this process, gasification of solid fuel happens in the fuel reactor which is fluidized by a gasifying agent, i.e, H 2 O. This process has been referred as in-situ Gasification CLC, iG-CLC. The feasibility of using fuels ranging from lignite to anthracite and the effect of the coal rank on the process performance was evaluated. The carbon capture efficiency followed the trend of the coal rank, as it was higher for lignite, then for the bituminous coals and it was lower for anthracite. Special attention was put on the combustion of the volatile matter of the different fuels. In all cases oxygen demands lower than 10% were found; for anthracite the oxygen demand values were 3.5% because of the lower volatile content of this fuel. A temperature increase was proven to be advantageous to reach high carbon capture and combustion efficiencies for all the fuels tested. Also, the feasibility of using H 2 O:CO 2 mixtures as gasification agent with each type of fuel was also assessed and it was seen that in case of bituminous coals and lignite some of H 2 O can be replaced by CO 2 .

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“…Since the process requires a good contact between gas and solids as well as a flow of solid material between the fuel and air reactors, the use of two interconnected fluidized beds have advantages over other designs. 8 The key issue in the CLC system performance is the oxygen carrier material. Iron-, nickel-, and copper-based oxygen carriers have been selected as the most promising materials to be used in a CLC process.…”

Section: Introductionmentioning

confidence: 99%

Reduction Kinetics of Cu-, Ni-, and Fe-Based Oxygen Carriers Using Syngas (CO + H₂) for Chemical-Looping Combustion

et al. 2007

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The reactivity of three Cu-, Fe-, and Ni-based oxygen carriers to be used in a chemical-looping combustion (CLC) system using syngas as fuel has been analyzed. The oxygen carriers exhibited high reactivity during reduction with fuel gases present in syngas (H 2 and CO), with average values in the range 8-30 % min -1 . No effect of the gas products (H 2 O, CO 2 ) on the reduction reaction rate was detected. The kinetic parameters of reaction with H 2 and CO have been determined by thermogravimetric analysis. The grain model with spherical or plate-like geometry in the grain was used for the kinetic determination, in which the chemical reaction controlled the global reaction rate. The * Corresponding author. Tel: +34976 733977. Fax: +46976 733318. E-mail: abad@icb.csic.esSubmitted, accepted and published by Energy & Fuels 2007, 21, 1843-1853 2 activation energies determined for these reactions were low, with values ranging from 14 to 33 kJ mol -1 .The reaction order depended on the reacting gas, and values from 0.5 to 1 were found. Moreover, the reactivity of the oxygen carriers when both H 2 and CO are simultaneously present in the reacting gases has been analyzed, both at atmospheric and pressurized conditions. For the Cu-and Fe-based oxygen carriers, the reaction rate of the oxygen carrier with syngas corresponded to the addition of the reaction rates for the individual fuel gases, H 2 and CO. For the Ni-based oxygen carrier the reaction rate was that corresponding to the fuel gas that reacted faster with the oxygen carrier at the reacting conditions (fuel concentration, temperature and pressure). The consequences of the behaviour of the reaction of syngas and the water-gas shift (WGS) equilibrium on the design of the fuel reactor of a CLC system have been analyzed. A preliminary estimation of the solids inventory for the use of syngas in the fuel reactor of a CLC system gave values in the range of 19-34 kg MW -1 when the WGS equilibrium was considered be instantaneous.

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A fluidized-bed combustion process with inherent CO2 separation; application of chemical-looping combustion

Cited by 946 publications

References 13 publications

Design of a rotary reactor for chemical-looping combustion. Part 2: Comparison of copper-, nickel-, and iron-based oxygen carriers

Design of a rotary reactor for chemical-looping combustion. Part 2: Comparison of copper-, nickel-, and iron-based oxygen carriers

Relevance of the coal rank on the performance of the in situ gasification chemical-looping combustion

Reduction Kinetics of Cu-, Ni-, and Fe-Based Oxygen Carriers Using Syngas (CO + H₂) for Chemical-Looping Combustion

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A fluidized-bed combustion process with inherent CO2 separation; application of chemical-looping combustion

Cited by 946 publications

References 13 publications

Design of a rotary reactor for chemical-looping combustion. Part 2: Comparison of copper-, nickel-, and iron-based oxygen carriers

Design of a rotary reactor for chemical-looping combustion. Part 2: Comparison of copper-, nickel-, and iron-based oxygen carriers

Relevance of the coal rank on the performance of the in situ gasification chemical-looping combustion

Reduction Kinetics of Cu-, Ni-, and Fe-Based Oxygen Carriers Using Syngas (CO + H2) for Chemical-Looping Combustion

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Reduction Kinetics of Cu-, Ni-, and Fe-Based Oxygen Carriers Using Syngas (CO + H₂) for Chemical-Looping Combustion