Thin-film-composite hollow fiber membranes containing amino acid salts as mobile carriers for CO2 separation

Abstract In this work, defect-free thin-film-composite (TFC) hollow fiber membranes containing various amino acid salts as CO 2 facilitated transport carriers were fabricated via dip-coating. Four different amino acid salts, i.e., potassium prolinate (ProK), potassium argininate (ArgK), potassium glycinate (GlyK) and potassium cysteinate (CysK), were selected and embedded within polyvinyl alcohol (PVA) matrix. TGA, FTIR, SEM and humid mixed gas permeation test were used for the evaluation. Experiments show that adding amino acid salts into the PVA matrix significantly increases the CO 2 permeance with little influence on the CO 2 /N 2 selectivity. ProK was found the most effective within the four investigated mobile carriers; The addition of 40% ProK into the PVA matrix nearly doubled the CO 2 permeance (from 399 to 791 GPU). The PVA/amino acid salt membranes also exhibited good long-term stability, in which both CO 2 permeance and CO 2 /N 2 selectivity remained nearly unchanged in a 20-h test and after a two-week shutdown period.