Pilot plant results for a precipitating potassium carbonate solvent absorption process promoted with glycine for enhanced CO₂ capture

The absorption performance of a glycine promoted precipitating potassium carbonate (K₂CO₃) solvent absorption process for carbon dioxide (CO₂) capture has been presented using a laboratory scale pilot plant. Glycine has been added as a rate promoter to 40-45 wt.% K₂CO₃ solutions to examine the enhancement of the CO₂ absorption process. The laboratory scale pilot plant has been designed to capture 4-10 kg/hr of CO₂ from an air/CO₂ mixture at a feed gas rate of 30-55 kg/hr. Performance data of the absorber including pressure drop, holdup and CO₂ removal efficiency has been collected from the pilot plant and presented for a range of operating conditions. The addition of glycine was found to improve the CO₂ recovery rate by up to 6 times whilst also slightly increasing the pressure drop and holdup measured in the packed absorption column which is likely due to a reduction in the surface tension of the solvent. Additionally, increasing the K₂CO₃ solvent concentration and operating with a higher CO₂ feed gas concentration were found to increase the CO₂ recovery results. Finally performance data from the absorber has been used to validate an Aspen Plus simulation of the system.