Henry’s\nVolatility of Acetaldehyde from Amine\nSolvents and Its Application in Estimating CO<sub>2</sub> Capture\nSystem Emissions

Aldehydes, including formaldehyde\nand acetaldehyde, are\ncommonly\nobserved as amine solvent degradation products in carbon capture systems.\nThese degradation products have the potential to cause environmental\nconsequences if they migrate to the flue gas and are emitted from\nCO<sub>2</sub> capture systems. A better understanding of the Henry’s\nvolatility coefficients of these compounds is needed to estimate the\ngas-phase partitioning of these compounds from the amine solvent and\nto aid in the development of proper mitigation strategies that can\nbe implemented within CO<sub>2</sub> capture systems. This work highlights\nthe experimental determination of the dimensionless Henry’s\nvolatility coefficient of acetaldehyde from unloaded and CO<sub>2</sub> loaded amine solvents using headspace solid-phase microextraction\nwith on-fiber derivatization and gas chromatography mass spectrometry\ndetection. The experimental dimensionless Henry’s volatility\ncoefficient was significantly higher from the amine solvent when compared\nto acetaldehyde’s partitioning coefficient from water due to\na “salting out” effect from increases in ionic strength\nwith CO<sub>2</sub> loaded amine solutions. A linear temperature and\nCO<sub>2</sub> loading dependency of the Henry’s volatility\ncoefficient was observed with acetaldehyde from the amine solvent.\nThe experimental Henry’s coefficient was then used to estimate\ngas-phase concentrations from carbon capture systems based on measured\nprocess temperatures, CO<sub>2</sub> loading in the solvent, and acetaldehyde\nliquid concentration values all measured from a pilot CO<sub>2</sub> capture system.