Stripping of CO₂ from different aqueous solvents using PVDF hollow fiber membrane contacting process

The stripping of carbon dioxide from liquid absorbents is an important task in the operation of gas-liquid membrane contacting processes. In order to gain a better understanding on the role of various absorbents on CO₂ stripping, potassium glycinate (PG), monoethanolamine (MEA), diethanolamine (DEA), and 2-amino-2-methyl-1-propanol (AMP) were applied as absorbent/stripping solutions. The membrane used for the experiments was hollow fiber polyvinylidenefluoride (PVDF) membrane fabricated via thermally induced phase separation method. The performances of various amine solutions on the CO₂ stripping capability were investigated. CO₂ stripping experiments revealed that regardless of type of solvent the CO₂ stripping flux and efficiency rapidly increases with liquid temperature, pressure and initial CO₂ concentration. In addition, the gas-liquid contact time was a key factor to enhance the stripping flux at low temperature while liquid phase boundary layer thickness and associated mass transfer resistance is important at elevated temperatures. Moreover the comparison stripping experiments between shell and tube side liquid flow revealed that for low packing density tube side flow gives better stripping performance.