CO2 Recovery at High Temperatures Using Ba2TiO4

We investigated the use of Ba2TiO4 to remove CO2 from a flow gas at high temperatures. Experiments using a CO2/N2 gas and a vertical reaction tube showed that the CO2 concentration of the exit gas can be reduced to 1% or less at 500 to 800°C (and to even 0.1% or less at 600°C) when the space velocity (SV) of the flow is 2000 h–1. Also, the CO2 concentration changes for the gas mass flow at 700°C or lower. From the results of reaction rate analysis of Ba2TiO4 and CO2, at temperatures of 550°C and higher, the activation energy was 12.5 kJ/mol, indicating that this range is a diffusion-rate controlled area. The reaction rate had a linear correlation with the CO2 concentration from 500 to 800°C, and the estimated reaction degree was 0.96. These results indicate that Ba2TiO4 can effectively remove CO2 from exhaust gas at high temperatures.