ELPI⁺ measurements of aerosol growth in an amine absorption column

Abstract

Recently, studies have appeared pointing out that aerosols can dominate the total amine emission from amine based PCCC pilot plant scale installations. For the design of countermeasure types (upstream or downstream of the PCCC installation), it is crucial to have an idea of the aerosol size distribution and numbers entering or leaving the absorber. This study is the first to present this kind of data and should serve future installations when designing aerosol emission countermeasures. H2SO4 aerosols entering the absorber are observed to be extremely small (i.e. <0.2μm) with number concentrations exceeding 1E8cm-3. The aerosols grow in size as they travel through the absorber through the taking up of water and amine to sizes close to but staying below 1μm. However, despite the fact that most of the aerosols (expressed in number concentrations) are well below 1μm, most of the water (and thus amine) is found in the aerosol sizes between 0.5 and 2μm. Therefore, if one aims at designing efficient countermeasures, eliminating this size fraction is crucial. This amine emission stream is therefore very difficult to remove using water washes as aerosols are known to travel through water wash sections. Moreover, also classical demisters show very little efficiency for these small aerosol sizes and are therefore believed not to be suitable for the removal of aerosols. This information will therefore serve future installations when designing aerosol emission countermeasures.