CO₂ Recovery at High Temperatures Using Ba₂TiO₄

Abstract

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.