钙钛矿型BaFeO_(3-δ)载氧体的制备与气化性能

Preparation and Gasification Performance of Perovskite-Type BaFeO_(3-δ) Oxygen Carrier

以柠檬酸作为络合剂,采用溶胶-凝胶法制备钙钛矿型BaFeO_(3-δ)载氧体,通过对产物进行XRD、TGDSC分析和固定床实验,考察了前驱液pH值及柠檬酸用量、热处理温度和煅烧气氛对产物物相的影响.结果表明,配制前驱液pH值为8、柠檬酸与金属硝酸盐摩尔比为1.5∶1时,凝胶内金属阳离子均匀性最好、产物中杂相最少;前驱体内有机物在285℃下可充分反应并释放大量气体,750℃煅烧最适合钙钛矿晶相形成;马弗炉煅烧产物内钙钛矿晶格含较多氧空位,氧空位的存在提高了生物质气化的碳转化率和合成气产率.

The perovskite-type BaFeO_(3-δ) oxygen carrier was prepared by the sol-gel method with citric acid as the complexing agent.The products were analyzed by XRD and TG-DSC,and a fixed bed experiment was conducted in order to investigate the influences of the pH value of the precursor solution and citric acid dosage,and the temperature and gas condition of calcination during the heat treatment on the products.The results show that when the precursor solution pH was 8 and the molar ratio of citric acid to metal nitrate was 1.5∶1,the distribution of metal cations in the gel was the most uniform and the impurity of products was the least.The organic matter in the precur-sor could fully react at 285℃and release a large amount of gas.The calcination at 750℃was the most suitable for the formation of perovskite crystal phase.The perovskite lattice in the calcined products in the muffle furnace con-tained more oxygen vacancies,and the existence of oxygen vacancies improved the carbon conversion rate and syngas yield of biomass gasification.