钠基负载型固体CO2吸收剂碳酸化反应特性

针对钠基固体吸收剂脱除燃煤烟气CO2技术存在的吸收剂活性成分碳酸钠与CO2的反应活性较低的问题，分别选取硅藻土、粗孔硅胶、ZrO2、TiO2和γ-氧化铝作为载体，Na2CO3作为活性成分，采用浸渍法制备成5种钠基吸收剂。利用热重分析装置、XRD、SEM和氮吸附仪研究各吸收剂的CO2捕捉性能。结果表明：分析纯Na2CO3与CO2的反应非常微弱；负载于硅藻土、粗孔硅胶和ZrO2后，Na2CO3主要发生水合反应，生成Na2CO3·1.5H2O，CO2吸收性能差；负载于TiO2后，碳酸化反应产物除了NaHCO3外，还有新产物Na5H3(CO3)4，CO2的吸收量低；负载于γ-氧化铝后，碳酸化反应产物仅为NaHCO3，反应速率快，CO2吸收量大，并从微观角度揭示了载体孔隙结构对碳酸化反应的影响机理。

Carbonation characteristics of sodium-based solid sorbents for CO2 capture

The CO2 emission control using sodium-based solid sorbents attracts much attention because the reaction temperature and energy consumption of the technology are low.However，it is understood that its primary shortcoming is its low reactivity with CO2 during sorption process.Diatomite，silica gel，ZrO2，TiO2 and γ-Al2O3 were investigated as potential supports for the cyclic Na2CO3/NaHCO3-based CO2 capture process.The five supported sorbents were characterized by TG，XRD，SEM and nitrogen adsorption.The results indicate that the carbonation characteristics of the five sorbents are different significantly.By using diatomite，silica gel and ZrO2 as a support，respectively，the principal reaction is hydration and the CO2 adsorption is weak.As for TiO2 support，the carbonate reaction products are NaHCO3 and Na5H3(CO3)4.γ-Al2O3 has a positive effect on the carbonation of Na2CO3 and the reaction rate，as well as the CO2 uptake，is observed to increase obviously.The carbonation product is NaHCO3.The effect mechanisms of supports on the carbonation of Na2CO3 were revealed by viewing the microstructure.