CO2 absorption and regeneration of alkali metal-based solid sorbents
CO2 absorption and regeneration of alkali metal-based solid sorbents
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DOI：
10.1016/j.cattod.2005.10.051
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发表时间：
2006-02-15
期刊：
影响因子：
5.3
通讯作者：
Kim, JC
中科院分区：
文献类型：
--
作者：
Lee, SC;Choi, BY;Kim, JC
以活性碳(AC)、二氧化钛、三氧化二铝、氧化镁、二氧化硅和各种沸石为载体，用碳酸钾浸渍法制备了钾基脱硫剂。在固定床反应器中，在不同温度条件下(60摄氏度的二氧化碳捕集和130-400摄氏度的再生)的多个循环中，测量了二氧化碳捕集能力和再生性能。K2CO3/AC、K2CO3/TiO2、K2CO3/MgO和K2CO3/Al_2O_3等吸附材料在130℃、130℃、350℃和400℃以上均可完全再生。K2CO3/Al_2O_3和K_2CO_3/MgO在低于200℃的温度下再生后，CO2捕集能力下降的原因可以解释为KAl(CO3)(2)(OH)(2)、K2 Mg(CO3)(2)和K2 Mg(CO3)(2)中心点4(H2O)的形成，这些中心点没有完全转化为原始的K2CO3相。在K2CO3/AC和K2CO3/TiO2中，与K2CO3/Al_2O_3和K_2CO_3/MgO不同，K2CO_3/AC和K_2CO_3/TiO_2在吸收CO2的过程中形成了KHCO_3晶体结构。在再生过程中，即使在较低的温度(130摄氏度)下，这一相也很容易转化为原始相。因此，CO2吸收后KHCO3晶体结构的形成是再生的重要因素，即使在低温下也是如此。载体的性质对二氧化碳的吸收和再生能力起着重要的作用。特别是K2CO3/TiO2光催化剂在吸收和再生CO2方面表现出优异的特性，它满足了在低温条件下(1atm，150℃)大量吸收CO2(mg CO2/g脱硫剂)和快速完全再生的要求。2005 Elsevier B.V.学位保留所有权利。
Potassium-based sorbents were prepared by impregnation with potassium carbonate on supports such as activated carbon (AC), TiO2, Al2O3, MgO, SiO2 and various zeolites. The CO2 capture capacity and regeneration property were measured in the presence of H2O in a fixed-bed reactor, during multiple cycles at various temperature conditions (CO2 capture at 60 degrees C and regeneration at 130-400 degrees C). Sorbents such as K2CO3/AC, K2CO3/TiO2, K2CO3/MgO, and K2CO3/Al2O3, which showed excellent CO2 capture capacity, could be completely regenerated above 130, 130, 350, and 400 degrees C, respectively. The decrease in the CO2 capture capacity of K2CO3/Al2O3 and K2CO3/MgO, after regeneration at temperatures of less than 200 degrees C, could be explained through the formation of KAl(CO3)(2)(OH)(2), K2Mg(CO3)(2), and K2Mg(CO3)(2)center dot 4(H2O), which did not completely converted to the original K2CO3 phase. In the case of K2CO3/AC and K2CO3/TiO2, a KHCO3 crystal structure was formed during CO2 absorption, unlike K2CO3/Al2O3 and K2CO3/MgO. This phase could be easily converted into the original phase during regeneration, even at a low temperature (130 degrees C). Therefore, the formation of the KHCO3 crystal structure after CO2 absorption is an important factor for regeneration, even at the low temperature. The nature of support plays an important role for CO2 absorption and regeneration capacities. In particular, the K2CO3/TiO2 sorbent showed excellent characteristics in CO2 absorption and regeneration in that it satisfies the requirements of a large amount Of C02 absorption (mg CO2/g sorbent) and fast and complete regeneration at a low temperature condition (1 atm, 150 degrees C). degrees 2005 Elsevier B.V. All rights reserved.