Study Of Experiment And Model On The Separate Process Of High-temperature CO₂

The danger brought by Green House Effect is growing worse. CO2 emission from fossil fuel combustion is the main cause of Global Warming. During many technologies of reducing CO2 emission, the circulating fluidized beds of calcium-based absorption used for carbonation/calcinations reaction (CCR) is an promising effective application. In this paper, experimental and model research study of calcium carbonate decomposition in CCR process have been done. A mathematic model which describes the decomposition of calcium carbonate pellets in pure CO2 environment has also been matched and verified..Calcination of calcium carbonate powder was completed in a fixed bed system in pure CO2 environment. We investigate the character of calcination and factors affecting it. The results indicate that the beginning decomposition temperature of calcium carbonate powder is around 900℃.The activation energy is about 147.42KJ/mol.Calcination of calcium carbonate pellets. The synthetic calcium-based absorption was prepared and calcined on fixed bed system in pure CO2 environment. The effect of content and dimension have been studied. The formula of the rate constant was also built via comparing with other researches. The activation energy is greater when the diameter is larger in the same content pellets. But the effect of content is more complex when diameter is the same.During the modeling of calcinations, a mathematic model based on Murthy model is used to describe the decomposition of calcium carbonate pellets in pure CO2 environment .The compare between simulated results and experimental data shows that the model works better when the rate of length to diameter is big enough. The research was supported by National Basic Research Program of China (No.2006CB705800) and Natural Science Foundation of China (No.50376016).