Trace metals accumulation in a coal-fired post combustion CO₂ capture process with amine-based solvents

Trace elements contained in coal-derived flue gas can accumulate in solvents used in post-combustion CO₂ capture with potential process and environmental impacts. The accumulation of six metals, arsenic, mercury, selenium, iron, nickel, and copper in three amine-based solvents was investigated in a 0.1MWth post-combustion CO₂ capture pilot unit from the combustion of coal for testing periods of 200-400h. Generally, the concentration of the metals increased over time at varying rates, with the coal used being the principal source for the build-up of most of them. The relatively lower concentrations of iron, nickel, and copper in one of the solvents showed that the type of solvent influenced its interaction with the metals and the rate of metals accumulation.