Abstract: Driven by increasing demands for energy and concerns for climate change, more attention are paid to the development of clean, efficient, and economical technologies for energy conversion, among which chemical looping is considered as a promising alternative for fossil fuel conversion. Chemical looping processes enable highly efficient in situ CO₂ capture in oxidation of carbonaceous fuels by making use of solid oxygen carriers. The Ohio State University (OSU) has developed a unique chemical looping technology utilizing iron-based oxygen carrier and moving bed reactors. Thermodynamic analysis shows that counter-current moving bed reactor can maximize oxygen carrier conversion while fully converting fuels, enabling high purity H₂ production by iron-steam reaction. OSU chemical looping is highly flexible for converting a variety of gaseous and solid fuels to electricity, H₂, and chemicals with CO₂ captured. To date, the syngas chemical looping (SCL) technology and the coal direct chemical looping technology has been successfully operated for more than 850 h in total on two 25 kW_th sub-pilot units. A 250 kW_th high pressure SCL pilot unit is constructed at National Carbon Capture Center and will be put into operation in 2014.

Key words: carbon capture, chemical looping, fossil fuel, coal, iron-based oxygen carrier, moving bed reactor

摘要： 在日益增长的能源需求与日益严峻的全球气候变化带来的双重压力下，清洁、高效且经济的能源利用方法显得尤为重要。将化学链概念用于传统化石能源的转化是一种前景广阔的新技术。化学链燃烧利用载氧体间接转化含碳燃料，同时实现二氧化碳的捕集。俄亥俄州立大学研发了采用铁基载氧体和移动床反应器的化学链技术，可实现天然气、煤、生物质等多种燃料向电力、氢、液体燃料等产品的零排放转化。目前，合成气化学链（syngas chemical looping，SCL）和煤直接化学链（coal direct chemical looping，CDCL）技术两套25 kW_th级小试装置已成功运行总计超过850 h，一套250 kW_th级的高压SCL装置即将投入示范运行。

关键词: 碳捕集, 化学链燃烧, 化石能源, 煤, 铁基载氧体, 移动床反应器