变温镁基CO_2吸附剂的制备及应用I.Na/Mg物质的量比

Preparation and application of magnesium-based CO_2 sorbent for temperature swing absorption I. Na /Mg mol ratio

以Mg(NO3)2和Na2CO3为原料,采用正加沉淀法制备镁基CO2吸附剂,利用XRD、SEM-EDS和DTG等方法对吸附剂进行了表征,研究了n(Na)/n(Mg)比对吸附剂的物质组成、形貌和分解温度的影响;在此基础上,通过变温吸附脱附动态循环实验考察了不同吸附剂的CO2吸附性能。实验结果表明,当n(Na)/n(Mg)为8.15时,吸附剂颗粒粒径小、大小均匀、分解温度低,吸附容量达到9.584%(质量分数);经过20次变温吸附脱附循环后,吸附能力仍保持初始吸附量的95.8%,表现出良好的稳定性。

A series of magnesium-based CO2 absorbents with different Na/Mg molar ratios were prepared by precipitation method with Mg （NO3 ）2 arid Na2CO3 as raw materials, and characterized by various methods （including XRD, SEM-EDS and DTG） to study the compositions, morphology and decomposition temperature and so on. The CO2 absorption performance was evaluated by temperature swing absorption-desorption dynamic cyclic tests to check the impact of Na/Mg molar ratio. It can be seen that optimum molecular ratio of Na to Mg is 8.15, and the sorbents is homogeneous with lower decomposition temperature caused by small particles of the sample, and initial CO： adsorption capacity can reach 9. 584%. Good recycling capability can be obtained as well. Compared with the initial absorption capacity, there was only 4.2% decrease after 20 recycles.