Reactivation of a CaO-based sorbent for CO2 capture from stationary sources

Blamey, John; Paterson, Nigel; Dugwell, D. R.; Stevenson, Paul; Fennell, Paul S.

doi:10.1016/j.proci.2010.07.052

Cited by 40 publications

(44 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, two major problems are encountered in this process: (1) the decline in CO 2 capture capacity of the sorbent due to sintering; and (2) the attrition and fragmentation of limestone due to mechanical and thermal stress [9]. The severity of these two effects has been found to increase with increasing number of reaction cycles [10,11]. Maintaining a high make-up flow to replace the spent sorbents and elutriated materials has been found to negatively influence the economics of the process [12].…”

Section: Introductionmentioning

confidence: 99%

Enhanced CO2 capture by biomass-templated Ca(OH)2-based pellets

Ridha

Manović

et al. 2015

Chemical Engineering Journal

View full text Add to dashboard Cite

Section: Introductionmentioning

confidence: 99%

Enhanced CO2 capture by biomass-templated Ca(OH)2-based pellets

Ridha

Manović

et al. 2015

Chemical Engineering Journal

View full text Add to dashboard Cite

“…The attractiveness of the Ca looping process arises from the fact that it uses industrially available circulating fluidized bed technology, and appears to be economically competitive with the commercially available amine-based absorption scrubbing (MacKenzie et al, 2007;Romeo et al, 2009). The circulation of sorbent between the carbonator and the calciner reactors requires, among other things, that the sorbent has good resistance to attrition in order to avoid excessive elutriation (Lu et al, 2008;Blamey et al, 2011). Also, as sorbent particles with diameters as large as 0.25 mm can still elutriate from a fluidized bed (Kunii and Levenspiel, 1991), there is some argument for studying particles of up to 1 mm or larger, which are outside of the typical circulating fluidized bed range.…”

Section: Introductionmentioning

confidence: 99%

High-temperature CO2 capture cycles for CaO-based pellets with kaolin-based binders

Ridha

Manović

Macchi

et al. 2012

International Journal of Greenhouse Gas Control

View full text Add to dashboard Cite

“…13,23,24 Hydration of calcined material followed by decomposition can be used as a regeneration method of sintered materials since it can restore a high surface area. [25][26][27][28] A major drawback of hydration as a regeneration method is the reduced mechanical strength of the regenerated material. 26,29,30 However, by hydrating in a CO 2 atmosphere, the reduction in mechanical strength can be retarded.…”

Section: Introductionmentioning

confidence: 99%

“…[25][26][27][28] A major drawback of hydration as a regeneration method is the reduced mechanical strength of the regenerated material. 26,29,30 However, by hydrating in a CO 2 atmosphere, the reduction in mechanical strength can be retarded. 31 Currently, thermogravimetric analysis (TGA) and bench scale reactors are the most common techniques for studying CO 2 capture by CaO based materials.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

In situ X-ray diffraction of CaO based CO2 sorbents

Molinder

Comyn

Hondow

et al. 2012

Energy Environ. Sci.

View full text Add to dashboard Cite

In situ X-ray diffraction coupled with Rietveld refinement has been used to study CO 2 capture by CaO, Ca(OH) 2 and partially hydrated CaO, as a function of temperature. Phase quantification by Rietveld refinement was performed to monitor the conversion to CaCO 3 and the results were compared to those derived using thermogravimetric analysis (TGA). It was found that Ca(OH) 2 converted directly to 100% CaCO 3 without the formation of a CaO intermediate, at ca. 600˚C. Both pure CaO and partially hydrated CaO (33.6 wt% Ca(OH) 2 ) reached the same capture capacity, containing approximately 65 wt% CaCO 3 at 800˚C. It was possible to provide direct evidence of the capture mechanism. The stresses in the Ca(OH) 2 phase of the partially hydrated CaO were found to be more than 20 times higher than its strength, leading to disintegration and the generation of nano-sized crystallites. The crystallite size determined using diffraction (75×16 nm) was in good agreement with the average crystallite size observed using TEM (of 83×16 nm). Electron diffraction images confirmed coexistence of CaO and Ca(OH) 2 . The analysis provides an explanation of the enhanced capture /disintegration observed in CaO in the presence of steam.Keywords: Rietveld analysis, in-situ X-ray diffraction, CaO, CO 2 capture, hydration, capture mechanism, attrition, regeneration, synchrotron. Graphical abstractIn situ XRD, in conjunction with phase quantification using Rietveld analysis, was used successfully to study CO 2 capture in CaO and Ca(OH) 2 as well as in partially hydrated CaO.The work shows how in situ XRD can be used as a supplemental technique to TGA, by which the mechanism of capture and hydration can be elucidated. IntroductionConcerns about global warming have prompted both national and international efforts to curb CO 2 emissions. CaO based materials are being considered as CO 2 sorbents for removal of CO 2 from flue gases at temperatures between 400˚C and 800˚C. Applications include pre-and post-combustion carbon capture technologies. [1][2][3][4][5][6][7][8][9][10] In addition, with the growing replacement of fossil fuels by biomass sources, and due to the high oxygen content of biomass, many of the processes of thermochemical fuel upgrading generate significant CO 2 at medium-high temperatures. [11][12] This provides the opportunity for in situ CO 2 capture in the 400-800˚C range and for improved heat transfer arising from the coupling of the endothermic gasification reactions with the exothermicity of the CO 2 chemisorption. This results in lower reaction temperatures and lower fuel consumption. [13][14] The advantages of CaO based materials as CO 2 sorbents for pre-and post-combustion CO 2 capture are their low cost, high abundance, large sorption capacity and fast reaction kinetics. 15-17 However, a major shortcoming of CaO based materials as CO 2 sorbents is the degradation in sorption capacity after multiple capture and regeneration cycles, due to loss of surface area through sintering. 18-21 For large scale CO 2 capture, th...

show abstract

Reactivation of a CaO-based sorbent for CO2 capture from stationary sources

Cited by 40 publications

References 17 publications

Enhanced CO2 capture by biomass-templated Ca(OH)2-based pellets

Enhanced CO2 capture by biomass-templated Ca(OH)2-based pellets

High-temperature CO2 capture cycles for CaO-based pellets with kaolin-based binders

In situ X-ray diffraction of CaO based CO2 sorbents

Contact Info

Product

Resources

About