Modification of pebax and zif-8/pebax membranes by additional solvent treatment to improve co2/n2 separation performance

Thesis Type: Postgraduate

Institution Of The Thesis: Middle East Technical University, Turkey

Approval Date: 2020

Student: Ala Abdulalem Abdo Moqbel Alsuhile



Capturing carbon dioxide is currently one of the most attractive research areas due to the serious problems that CO2 emission creates for the environment. The main aim of this work is to utilize cheap and environmentally friendly methods with simple synthesizing systems to enhance the separation performance of CO2 from N2 using PEBAX 1657 membranes. Thus, in this study, solvent modification and double-layer methods were used to improve the permeability of carbon dioxide in pure PEBAX 1657 and ZIF-8/PEBAX with an insignificant drop in the selectivity. The membrane modified by the solvent modification method improved the CO2 permeability by 1.21 compared to the single-layer 4 wt % PEBAX 1657 membrane which has a CO2 permeability of 155.2 Barrer. The modified membranes achieved a permeability of 188 Barrer. Furthermore, the CO2 permeability of double-layer membranes with different PEBAX 1657 in the top layer (4, 2, and 1 wt%) was higher by 1.13, 1.23, and 1.33; respectively, compared to single-layer 4 wt % PEBAX 1657 membrane. In MMMs, the double-layers membranes had permeabilities of 209.0 and 254.0 Barrer. These values are higher than single-layer membranes of MMMs by 1.14 and 1.3, respectively. The selectivity for separating CO2/N2 of all membranes ranged between 34.0-41.0. Thus, this study proposed two cheap synthesizing processes that enhanced the permeability of PEBAX 1657 membranes.