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Okunev, A. G.; Sharonov, V.E.; Aristov, Yu. I.; Parmon, Valentin N.

doi:10.1023/a:1010395630719

Cited by 70 publications

(35 citation statements)

References 4 publications

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“…After CO 2 absorption at 60°C, the XRD pattern of the sorbent showed the KHCO 3 phase only [35][36][37][38]. It has been reported that potassium hydrogen carbonate (KHCO 3 ) was formed through the reaction, K 2 CO 3 þ H 2 O þ CO 2 2KHCO 3 ; in the presence of H 2 O over potassium-based sorbents [18][19][20][21][22][23][24][25]. Water vapor is always necessary in the CO 2 absorption as shown in the absorption mechanism.…”

Section: Co 2 Absorption and Regeneration Propertiesmentioning

confidence: 99%

“…It has been reported that the formation of active species, K 2 CO 3 Á1.5H 2 O, plays an important role in the CO 2 capture capacity, and that the pretreatment process with water vapor, before CO 2 absorption, is directly related to the CO 2 capture capacity [19,20,[22][23][24]. The pretreatment process is defined as the absorption process of water vapor in the sorbent for 2 h before CO 2 absorption.…”

Section: The Role Of Water Vapor In the Pretreatment And In The Co 2 mentioning

confidence: 99%

“…Alkali metal carbonates such as Na 2 CO 3 and K 2 CO 3 react with CO 2 and H 2 O and transform to alkali metal hydrogen carbonates after CO 2 absorption by the following reaction, M 2 CO 3 þ CO 2 þ H 2 O 2MHCO 3 ðM ¼ Na; KÞ [18][19][20][21][22][23][24][25][26][27][28][29]. Water vapor is always necessary in forming potassium hydrogen carbonate in all reactions as shown in the absorption mechanism, unlike alkaline earth metalbased sorbents, while moisture contained in the flue gases as high as 8-17 vol.% negatively affected the adsorption capacity of molecular sieves [9].…”

Section: Introductionmentioning

confidence: 99%

“…The samples containing K 2 CO 3 Á1.5H 2 O in pores were characterized by the maximal CO 2 capture capacity. Several studies regarding an efficient chemical absorption over K 2 CO 3 , which was supported either on activated carbon [19,20] or on other porous matrices such as silica gel, Al 2 O 3 and vermiculite [22][23][24][25], were also reported using cyclic fixed-bed operations under moist conditions. Ryu et al also studied a dry regenerable sorbent, which involves high CO 2 capture capacity and a high attrition resistant, for CO 2 absorbed from flue gas produced by fossil fuel-fired power plants including industrial boilers before being released to the atmosphere or from a fuel gas stream such as syngas produced by conversion of fossil fuel [26].…”

Section: Introductionmentioning

confidence: 99%

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Dry Potassium-Based Sorbents for CO2 Capture

2007

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Dry potassium-based sorbents were prepared by impregnation with potassium carbonate on supports such as activated carbon (AC), TiO 2 , Al 2 O 3 , MgO, CaO, SiO 2 and various zeolites. The CO 2 capture capacity and regeneration property of various sorbents were measured in the presence of H 2 O in a fixed bed reactor, during multiple cycles at various temperature conditions (CO 2 absorption at 50-100°C and regeneration at 130-400°C). The KAlI30, KCaI30, and KMgI30 sorbents formed new structures such as KAl(CO 3 ) 2 (OH) 2 , K 2 Ca(CO 3 ) 2 , K 2 Mg(CO 3 ) 2 , and K 2 Mg(CO 3 ) 2 Á4(H 2 O), which did not completely convert to the original K 2 CO 3 phase at temperatures below 200°C, during the CO 2 absorption process in the presence of 9 vol.% H 2 O. In the case of KACI30, KTiI30, and KZrI30, only a KHCO 3 crystal structure was formed during CO 2 absorption. The formation of active species, K 2 CO 3 Á1.5H 2 O, by the pretreatment with water vapor and the formation of the KHCO 3 crystal structure after CO 2 absorption are important factors for absorption and regeneration, respectively, even at low temperatures (130-150°C). In particular, the KTiI30 sorbent showed excellent characteristics with respect to CO 2 absorption and regeneration in that it satisfies the requirements of a large amount of CO 2 absorption (87 mg CO 2 /g sorbent) without the pretreatment with water vapor, unlike KACI30, and a fast and complete regeneration at a low temperature condition (1 atm, 150°C). In addition, the higher total CO 2 capture capacity of KMgI30 (178.6 mg CO 2 /g sorbent) than that of the theoretical value (95 mg CO 2 /g sorbent) was explained through the contribution of the absorption ability of MgO support. In this review, we introduce the CO 2 capture capacities and regeneration properties of several potassium-based sorbents, the changes in the physical properties of the sorbents before/after CO 2 absorption, and the role of water vapor and its effects on CO 2 absorption.

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Section: Co 2 Absorption and Regeneration Propertiesmentioning

confidence: 99%

Section: The Role Of Water Vapor In the Pretreatment And In The Co 2 mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Dry Potassium-Based Sorbents for CO2 Capture

2007

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“…However, when CO 2 reacts with Na 2 CO 3 , the rate of global carbonation is rather slow (Zhao et al 2009). The CO 2 adsorption and regeneration using potassium-based sorbents with several supports such as activated carbon (Hirano et al 1995;Hayashi et al 1998;Shigemoto et al 2006), TiO 2 , SiO 2 , MgO, ZrO 2 , CaO and Al 2 O 3 were also reported in previous studies (Okunev et al 2000(Okunev et al , 2003Lee et al 2004;Liang et al 2004). Al 2 O 3 is one of the ideal materials used as a sorbent support.…”

Section: Introductionmentioning

confidence: 53%

Preparation of a Low-Cost K₂CO₃/Al₂O₃ Sorbent for CO₂ Capture at Flue-Gas Operating Conditions

Esmaili

Ehsani

2013

Adsorption Science & Technology

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ABSTRACT:In this study, the efficiency of a low-cost K 2 CO 3 /Al 2 O 3 sorbent as a CO 2 capture support was investigated. The sorbent was prepared by impregnating K 2 CO 3 on industrial-grade Al 2 O 3 . The CO 2 capture capacity of the sorbent was calculated from the breakthrough curve of the CO 2 adsorption inside a fixed-bed reactor, in the presence of H 2 O and at an adsorption temperature of 60 °C. An adsorption capacity of 75.4 mg CO 2 /g of sorbent was obtained. The stability of capture capacity of the sorbent was higher than that of the reference sorbent. The changes in the pore volume and surface area were 0.020 cm 3 /g and 5.5 m 2 /g, respectively, after five cycles of adsorption and regeneration. However, there were minor changes in the pore-size distribution and surface area of the sorbent after five cycles. This sorbent can be considered to be used in large-scale applications.

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A computational fluid dynamics design of a carbon dioxide sorption circulating fluidized bed

2010

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A kinetic theory based hydrodynamic model with experimentally determined sorption rates for reaction of CO 2 with K 2 CO 3 solid sorbent is used to design a compact circulating fluidized bed sorption-regeneration system for CO 2 removal from flue gases. Because of high solids fluxes, the sorber does not require internal or external cooling. The output is verified by computing the granular temperatures, particle viscosities, dispersion, and mass transfer coefficients. These properties agree with reported measurement values except the radial dispersion coefficients, which are much higher due to the larger bed diameter. With the solid sorbent prepared according to published information, the CO 2 removal percentage at the riser top is 69.16%. To improve the CO 2 removal, an effort is needed to develop a better sorbent or to simply lower the inlet gas velocity to operate in a denser mode, leading to a larger system. Also, the effect of temperature rise on the removal efficiency is investigated.

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Cited by 70 publications

References 4 publications

Dry Potassium-Based Sorbents for CO2 Capture

Dry Potassium-Based Sorbents for CO2 Capture

Preparation of a Low-Cost K₂CO₃/Al₂O₃ Sorbent for CO₂ Capture at Flue-Gas Operating Conditions

A computational fluid dynamics design of a carbon dioxide sorption circulating fluidized bed

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Untitled

Cited by 70 publications

References 4 publications

Dry Potassium-Based Sorbents for CO2 Capture

Dry Potassium-Based Sorbents for CO2 Capture

Preparation of a Low-Cost K2CO3/Al2O3 Sorbent for CO2 Capture at Flue-Gas Operating Conditions

A computational fluid dynamics design of a carbon dioxide sorption circulating fluidized bed

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Preparation of a Low-Cost K₂CO₃/Al₂O₃ Sorbent for CO₂ Capture at Flue-Gas Operating Conditions