Dry potassium-based sorbents for CO2 capture
Dry potassium-based sorbents for CO2 capture
复制标题
DOI：
10.1007/s10563-007-9035-z
复制
发表时间：
2007-12-01
影响因子：
3
通讯作者：
Kim, Jae Chang
中科院分区：
文献类型：
--
作者：
Lee, Soo Chool;Kim, Jae Chang
用碳酸钾浸渍在活性炭、TiO2、Al2O3、MgO、CaO、SiO2和各种沸石等载体上制备干型钾基吸附剂。在固定床反应器中，在不同温度条件下（50-100℃的CO2吸收和130-400℃的再生），测试了不同吸附剂在H2O存在下的CO2捕获能力和再生性能。KAlI30、KCaI30和KMgI30吸附剂在9 vol.% H2O存在下的CO2吸收过程中，在温度低于200℃的条件下，形成了KAl(CO3)(2)(OH)(2)、K2Ca(CO3)(2)、K2Mg(CO3)(2)和K2Mg(CO3)(2)中心点4（H2O）等新结构，并没有完全转化为原来的K2CO3相。对于KACI30、KTiI30和KZrI30，在CO2吸收过程中只形成了KHCO3晶体结构。水蒸气预处理后活性物质K2CO3中心点1.5H(2)O的形成和CO2吸收后形成的KHCO3晶体结构分别是吸附和再生的重要因素，即使在低温（130 ~ 150℃）下也是如此。特别是，KTiI30吸附剂在CO2吸收和再生方面表现出优异的特性，与KACI30不同，它不需要水蒸气预处理就能大量吸收CO2 （87 mg CO2/g吸附剂），并且在低温条件下（1atm, 150℃）能快速完全再生。此外，KMgI30的总CO2捕集能力（178.6 mg CO2/g吸附剂）高于理论值（95 mg CO2/g吸附剂），这可以通过MgO载体的吸附能力的贡献来解释。本文综述了几种钾基吸附剂的CO2捕集能力和再生性能，吸收CO2前后吸附剂物理性能的变化，以及水蒸气的作用及其对CO2吸收的影响。
Dry potassium-based sorbents were prepared by impregnation with potassium carbonate on supports such as activated carbon (AC), TiO2, Al2O3, MgO, CaO, SiO2 and various zeolites. The CO2 capture capacity and regeneration property of various sorbents were measured in the presence of H2O in a fixed bed reactor, during multiple cycles at various temperature conditions (CO2 absorption at 50-100 degrees C and regeneration at 130-400 degrees C). The KAlI30, KCaI30, and KMgI30 sorbents formed new structures such as KAl(CO3)(2)(OH)(2), K2Ca(CO3)(2), K2Mg(CO3)(2), and K2Mg(CO3)(2)center dot 4(H2O), which did not completely convert to the original K2CO3 phase at temperatures below 200 degrees C, during the CO2 absorption process in the presence of 9 vol.% H2O. In the case of KACI30, KTiI30, and KZrI30, only a KHCO3 crystal structure was formed during CO2 absorption. The formation of active species, K2CO3 center dot 1.5H(2)O, by the pretreatment with water vapor and the formation of the KHCO3 crystal structure after CO2 absorption are important factors for absorption and regeneration, respectively, even at low temperatures (130 150 degrees C). In particular, the KTiI30 sorbent showed excellent characteristics with respect to CO2 absorption and regeneration in that it satisfies the requirements of a large amount of CO2 absorption (87 mg CO2/g sorbent) without the pretreatment with water vapor, unlike KACI30, and a fast and complete regeneration at a low temperature condition (1 atm, 150 degrees C). In addition, the higher total CO2 capture capacity of KMgI30 (178.6 mg CO2/g sorbent) than that of the theoretical value (95 mg CO2/g sorbent) was explained through the contribution of the absorption ability of MgO support. In this review, we introduce the CO2 capture capacities and regeneration properties of several potassium-based sorbents, the changes in the physical properties of the sorbents before/after CO2 absorption, and the role of water vapor and its effects on CO2 absorption.