水蒸汽对钾基吸附剂CO2吸附机理影响研究

The technology of CO2 capture, storage and utilization (CCSU) was proposed as one of short-term goal for CO2 mitigation. CO2 chemical adsorption using alkali metal-based sorbents had attracted much attention due to the low cost of raw materials and non-corrosion property. However, the effect of steam on CO2 adsorption mechanism over the sorbent is still in the preliminary stage of exploration.Thus,the present project started with the nature of adsorption mechanism itself, including the investigation of dynamic behavior (formation, conversion) and static properties (morphology, location and characters) of the active components. The adsorption mechanism between active components and CO2 will be investigated to reveal the intrinsic reasons of adsorption CO2 in the steam atmosphere.Furthermore,to optimize the morphology structure of the sorbent and reaction conditions of adsorption CO2 required.Based on the above, the design of sorbent and operation window will be optimized, and make the CO2 capture process more stable.

CO2捕获、封存及利用技术被认为是短期之内应对气候变化的重要技术手段之一。由于碱金属固体吸附剂具有原料成本低、循环利用效率高、对设备无腐蚀等优点而被视为是一种具有应用前景的CO2吸附剂。但反应气氛下水蒸汽对吸附剂CO2吸附机理的影响研究仍处于初步探索阶段。本课题拟从吸附机理研究角度出发，具体研究水蒸汽条件下K基吸附剂表面活性组分生成的动态行为（生成、变化）和静态性质（形貌、位置、性质），明确活性组分与CO2的作用机理，进而揭示水蒸汽气氛下吸附剂CO2吸附的内在原因，获取促进吸附CO2所需的吸附剂形貌和反应条件要素，以指导吸附剂的设计和操作窗口的选择，进一步增强实际过程的稳定性。

碱金属固体吸附剂被视为是一种具有应用前景的CO2吸附剂。本项目详细研究了水蒸汽条件下K基吸附剂吸附CO2机理。对于KMgAlI3010吸附剂，经过水蒸气预处理后，K2CO3主要转化活性组分K4H2(CO3)3·1.5H2O，当进行CO2吸附时主要生成了KHCO3；而对于KMgAlI3020吸附剂，当水蒸气预处理5-20 min（水蒸气含量为3.0-8.6 wt%）时，活性组分Mg4Al2(OH)12CO3·3H2O吸附CO2后转化为Mg2Al2(CO3)4(OH)2·15H2O。当水蒸气预处理时间继续增大85-265 min（水蒸气含量为12.8-34 wt%）时，此时更利于向生成KHCO3的方向进行，在此基础上，采用中试规模循环流化移动床条件下，测试了K基吸附剂CO2吸脱附性能。