PCC pilot plant studies with aqueous potassium glycinate

Abstract

The present research work discusses the suitability of aqueous potassium glycinate (KGly) in a PCC-pilot plant. Reference is made to measurement results with aqueous sodium glycinate (NaGly). The use of real power plant flue gas and the well-conceived dimensions of the test facility enable industry-related conditions for full-scale applications.Although 40wt% KGly has faster kinetics in unloaded state, no enhancements in plant operation could be achieved in comparison to 40wt% NaGly. Just like with NaGly, the difficult feasibility of KGly regeneration leads to slow CO2 absorption rates, resulting in a huge energy demand >5.5 GJ/tCO2. A far lower energy demand of 3.68 GJ/tCO2 was measured for 30wt% MEA. The required solvent flow rate for reaching the optimal operating point is high (L/G-ratio=9l/m3). The pilot plant was operated with a massive reduced flue gas flow (40% of the dimensioning) in order to prevent instable operation and to reach the desired CO2 separation efficiency of 90%. During a prolonged shutdown, excessive carbonate was formed in the desorber column, resulting in a further reduction of the flue gas flow rate. Measurements of the ammonia content of the treated flue gas exhibit that the solvent degrades enormously.