Real-Time Aerosol Measurements in Post-Combustion CO2 Capture Using ELPI+™ and Smooth and Sintered Collection Plates

Abstract

The aerosols from CO2-depleted flue gas at the National Carbon Capture Center (NCCC) Pilot Solvent Test Unit (PSTU) and Slipstream Solvent Test Unit (SSTU) were measured in real-time using a Dekati Electric Low Pressure Impactor (ELPI+™). The coal-fired flue gas is provided by Alabama Power's Gaston Power Plant Unit 5. The utilization of ELPI+™ for aerosol research in postcombustion CO2 capture is very important due to its quick response time with size classification as low as 6 nm under transient conditions observed at the NCCC. Different process changes have been quantified at the PSTU and SSTU by multiple tests using the ELPI+™. The performance of smooth and sintered collection plates during dynamic process changes has been investigated. Between separate tests, upstream at unit 5, a new baghouse was installed. The aerosols measured at SSTU, before and after the baghouse installation, are compared. PSTU measurements demonstrated sample sensitivity to transient intercooler start-up conditions and dilution gas temperatures. During the tests, the typical concentration ranged from 106 to 107 cm−3. The aerosol's counter median diameter (CMD) for the sintered plates are lower (47–60 nm) compared to the normal plates (89–130 nm). The optical images indicate that sintered plates soak up all of the collected aerosols. The aerosol number concentration showed a significant drop after the baghouse installation. These results are promising and will enable the development of process control strategies to mitigate solvent losses and reduce operation and maintenance expenses.