钙钛矿型金属氧化物是一种优良的制备O2/CO2混合气体的载氧体,分别用柠檬酸溶胶凝胶法和EDTA-NH4-OH法制备了4种不同的钙钛矿型金属氧化物,采用X射线衍射分析表征不同钙钛矿金属氧化物的物相组成并在固定床实验台架上用气体分析仪对它们的与CO2的反应性能及其影响因素进行比较和研究。结果表明,新型BSCF载氧体的释氧性能最好,预处理时间及温度条件都会对新型钙钛矿型金属氧化物的释氧性能产生较大影响,且新鲜样品和循环后的样品的最佳反应条件有所不同。新鲜样品当预处理温度为800℃,预处理时间为1h时,BSCF释氧能力最佳,而第二次循环之后的最佳预处理温度在850℃左右。
Perovskite-type sorbents have been identified as great potential oxygen-carriers to produce oxygen enriched carbon dioxide stream. Sol-gel combustion synthesis method using different complexant, EDTA-NH4-OH and citric acid, was used for the preparation of four different pervoskite-type sorbents. The transient phase changes of the perovskite type oxides were characterized by X-ray diffraction (XRD) analysis, and the oxygen desorption ability as well as their influence factors were investigated in a fixed bed. The experimental results indicate that novel Ba0.5Sr0.5Co0.8Fe0.2O3-δ (BSCF) provides the best performance of oxygen desorption ability. Besides, both the pretreatment temperature and time have a great effect on the oxygen desorption ability of perovskite-type oxides. While a pretreatment condition of 800 ℃ for 1 h is optimal for the oxygen desorption of fresh BSCF, 850 ℃ is optimal for the BSCF after one cycle.