Study of a novel solvent system for CO₂ capture from postcombustion flue gas

CAER-S2 solvent system developed in the Center for Applied Energy Center at the University of Kentucky has the advantages of fast CO₂ removal rate, high thermal stability, low volatility, and commercial quantity available. Vapor liquid equilibrium measurement shows that the solvent has a lower partial pressure than that of MEA at scrubber temperatures. Such feature makes the solvent a promising candidate for carbon capture from natural gas-fired flue gas which has low CO₂ concentration. Mass transfer coefficients of CO₂ in the solvent system are tested using a wetted-wall column with simulated gases at the scrubber condition. Experimental results indicate that the mass transfer coefficient increases with the increasing of temperature over the studied range, which is different from the studies on MEA. Such results suggest that the solvent is preferable to be operated at elevated temperature in scrubber at which physical mass transfer limitation is minimized without sacrificing too much driving force.