Removal of CO2 in a multistage fluidized bed reactor by amine impregnated activated carbon: optimization using response surface methodology.

Carbon dioxide (CO₂) is the major component of greenhouse gas. Increase in concentration of CO₂ in the atmosphere leads to global warming. To remove the CO₂ from waste flue gas a four-stage counter-current multistage fluidized bed adsorber was developed and operated in continuous bubbling fluidization regime for the two-phase system. This paper describes the optimum condition for CO₂ removal efficiency in a multistage fluidized bed reactor using amine impregnated activated carbon. Response surface methodology with central composite design was used to determine the effect of three variables on the response. The variables are inlet concentration of CO₂ in ppm (ranging from 3000 to 20,000), impregnation ratio of monoethanol amine (ranging from 0.2 to 0.6) and weir height in mm (20–60). The response was CO₂ removal efficiency. The factor which was most influential has been identified from the analysis of variance. The optimum CO₂ removal efficiency for the amine impregnated activated carbon (MEA-AC) was found to be 95.17%, at initial concentration of CO₂ 7312.85 ppm, chemical impregnation ratio of 0.31, and weir height 48.65 mm. From the experiment, the CO₂ removal efficiency was found to be 95.97% at the same operating conditions. The predicted response was found to relevance with experimental data. [ABSTRACT FROM AUTHOR]