Calcium Looping: Sorbent and Process Characterization in a 20 kWth Dual Fluidized Bed

Calcium looping technology is an attractive method for CO2 capture in dual fluidized bed combustion (FBC) reactors. The major limit for this technology is that the capture capacity of CaO-based sorbents sharply decreases with increasing cycle numbers. Attrition and consequent elutriation of CaO-based sorbents from FBC reactors also limit its application. In order to overcome these shortcomings, doping with framework materials is shown as a promising potential solution. Therefore, this work looks at a review of the CO2 capture capacities of CaO-based sorbents doped with different framework materials, such as aluminate cements, kaolin, aluminum oxides, magnesium oxide, titanium dioxide, and lanthanum salt. The synthetic sorbents have a better performance in CO2 capture capacities than the original sorbents in long term carbonation/calcination cycles.

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Parametric investigation of the calcium looping process for CO2 capture in a 10kWth dual fluidized bed

International Journal of Greenhouse Gas Control ◽

10.1016/j.ijggc.2010.04.009 ◽

2010 ◽

Vol 4 (5) ◽

pp. 776-784 ◽

Cited By ~ 120

Author(s):

A. Charitos ◽

C. Hawthorne ◽

A.R. Bidwe ◽

S. Sivalingam ◽

A. Schuster ◽

...

Keyword(s):

Fluidized Bed ◽

Co2 Capture ◽

Parametric Investigation ◽

Calcium Looping ◽

Dual Fluidized Bed

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Analysis of the calcium looping system behavior by implementing simple reactor and attrition models at a 10 kW th dual fluidized bed facility under continuous operation

Fuel ◽

10.1016/j.fuel.2015.11.070 ◽

2016 ◽

Vol 169 ◽

pp. 79-86 ◽

Cited By ~ 6

Author(s):

Glykeria Duelli (Varela) ◽

Alexandros Charitos ◽

Nina Armbrust ◽

Heiko Dieter ◽

Günter Scheffknecht

Keyword(s):

Fluidized Bed ◽

Continuous Operation ◽

System Behavior ◽

Calcium Looping ◽

Dual Fluidized Bed

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Analysis and Comparison of Reactivity and CO2 Capture Capacity of Fresh Calcium-Based Sorbents and Samples From a Lab-Scale Dual Fluidized Bed Calcium Looping Facility

Volume 3: Controls, Diagnostics and Instrumentation; Cycle Innovations; Marine ◽

10.1115/gt2010-22192 ◽

2010 ◽

Author(s):

Senthoorselvan Sivalingam ◽

Stephan Gleis ◽

Hartmut Spliethoff ◽

Craig Hawthorne ◽

Alexander Charitos ◽

...

Keyword(s):

Fluidized Bed ◽

Co2 Capture ◽

Test Facility ◽

Experimental Conditions ◽

Fast Heating ◽

Fresh Sample ◽

Calcium Looping ◽

Process Modification ◽

Dual Fluidized Bed ◽

Capture Capacity

Naturally occurring limestone and samples from a lab scale dual fluidized bed (DFB) calcium looping (CaL) test facility were analysed in a thermo gravimetric analyser (TGA). The reactivity of the samples evaluated at typical carbonation conditions prevailed in the carbonator was compared with raw samples. Carbonations were carried out at 600, 650 &700°C and 5, 10 &15 vol-% CO2 atmosphere using a custom designed sample holder that provided ideal conditions for solid gas contact in a TGA. The rate of carbonation and carbonation capacity of the samples were compared with respect to the following three categories: number of calcination-carbonation cycles, carbonation temperature and CO2 concentration. Notable differences in total conversion (XCaO) and the rates of conversions were observed between the raw and DFB samples in all three cases. It is suspected the much lower activity of the DFB sample is attributed to the differences in experimental conditions: ie., partial carbonation of the DFB particles, fast heating rate in the calciner and thus a rapid calcination reaction, and particle attrition in the CFB calciner riser. These harsh conditions lead sintering and thus a loss of surface area and reactivity. Sintered DFB samples showed low (nearly 1/3 of the raw samples) but stable conversions with increasing number of cycles. The sorbent taken from the DFB facility did not decrease with respect to carbonation rate or maximum conversion over 4 cycles whereas the fresh limestone changed significantly over 4 cycles. Hydration was used as an attempt to regenerate the lost capture capacity of partially carbonated DFB sample. Hydration of the sintered DFB sample was successful in increasing the maximum capture capacity in the fast reaction regime to values almost as high as that of a fresh sample in its first carbonation cycle. Although more investigation is required to investigate the effect of hydration on the CaO particle morphology, a process modification to enhance the CO2 capture efficiency of the carbonator via particle hydration was proposed.

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Analysis and Comparison of Reactivity and CO2 Capture Capacity of Fresh Calcium-Based Sorbents and Samples From a Lab-Scale Dual Fluidized Bed Calcium Looping Facility

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4002683 ◽

2011 ◽

Vol 133 (7) ◽

Cited By ~ 1

Author(s):

Senthoorselvan Sivalingam ◽

Stephan Gleis ◽

Hartmut Spliethoff ◽

Craig Hawthorne ◽

Alexander Charitos ◽

...

Keyword(s):

Fluidized Bed ◽

Co2 Capture ◽

Test Facility ◽

Experimental Conditions ◽

Fast Heating ◽

Fresh Sample ◽

Calcium Looping ◽

Process Modification ◽

Dual Fluidized Bed ◽

Capture Capacity

Naturally occurring limestone and samples from a lab-scale dual fluidized bed (DFB) calcium looping test facility were analyzed in a thermogravimetric analyzer. The reactivity of the samples evaluated at typical carbonation conditions prevailed in the carbonator was compared with raw samples. The rate of carbonation and carbonation capacity of the samples were compared with respect to the following three categories: number of calcination-carbonation cycles, carbonation temperature, and CO2 concentration. It is suspected that the much lower activity of the DFB sample is attributed to the differences in experimental conditions, i.e., partial carbonation of the DFB particles, fast heating rate in the calciner and thus a rapid calcination reaction, and particle attrition in the circulating fluidized bed calciner riser. These harsh conditions lead to sintering and thus a loss of surface area and reactivity. Sintered DFB samples showed low (nearly one-third of the raw samples) but stable conversions with increasing number of cycles. Hydration was used as an attempt to regenerate the lost capture capacity of partially carbonated and sintered DFB sample. Hydration of the DFB sample was successful in increasing the maximum capture capacity in the fast reaction regime to values almost as high as that of a fresh sample in its first carbonation cycle. Although more investigation is required to investigate the effect of hydration on the CaO particle morphology, a process modification to enhance the CO2 capture efficiency of the carbonator via particle hydration was proposed.

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