核壳结构铜基氧载体的化学链制氧

Chemical Looping Air Separation Using a Cu-Based Oxygen Carrier with Core-Shell Structure

针对化学链制氧中使用的氧载体,采用自组装模板燃烧法制备了一种具有核壳结构的高性能铜基氧载体.该氧载体颗粒具有一种微观的分层结构,其中活性成分铜均匀地负载在纳米结构的核(Al2O3)-壳(Ti O_2)上,由于二氧化钛层形成的壳阻止了氧化铝和氧化铜的接触,从而避免了CuAl_2O_4的生成,减少了活性成分损失.利用热重分析仪研究了反应温度对氧载体吸氧、释氧的影响,并在小型流化床上探究了流化气流量对释氧速率的影响.结果表明,温度越高,释氧过程越快,吸氧过程越慢.研究了释氧过程中,流化气流量存在一个最优值使释氧速率达到最大值,同时出口气体中氧气浓度较高.十次循环制氧实验结果表明,该氧载体具有很高的载氧率和稳定性,适用于化学链制氧.

Aiming at chemical looping air separation （CLAS） for oxygen production, a Cu-based oxygen carrier with hierarchical core-shell structure was synthesized by self-assembly template combustion synthesis （SATCS）method. The active component CuO was uniformly loaded on the core （Al2O3）-shell （TiO2） microarchitecture, which effectively reduced the formation of CuAl2O4 by preventing the reaction between Al2O3 and CuO through the intermediate layer TiO2. The oxygen carrier was tested on a thermogravimetric analyzer and a batch fluidized bed reactor to research the effect of temperature and fluidizing gas flow in the CLAS process. The results showed that increasing reaction temperature could promote the oxygen release rate but decrease the oxygen uptake rate. There was an optimal value for the fluidizing gas flow rate, at which the oxygen release rate could reach a maximum with a high oxygen content of outlet gas. Finally, 10 cyclic CLAS experiments were conducted in the batch fluidized bed reactor. The oxygen carrier showed high oxygen capacity and stability, which is applicable to the CLAS process.