Enhanced Pressure Swing Membrane Absorption Process for CO2 Removal From Pre-Combustion Syngas With Dendrimer-Ionic Liquid Mixtures As Absorbent

Using pure ionic liquid [bmim][DCA] and its dendrimer-containing solutions as absorbents, studies of a novel 5-valve pressure swing membrane absorption (PSMAB) process for CO₂ removal from pre-combustion syngas were carried out with porous hydrophobized polyether ether ketone (PEEK) hollow fiber membrane modules having different characteristics. The optimal absorption step in each cycle was determined. It is determined that reducing the dead volume on the module tube side and decreasing the fiber packing density greatly enhanced gas absorption and improved product qualities while increasing temperature had a negative impact on product qualities with pure [bmim][DCA] as absorbent. Adding polyamidoamine (PAMAM) dendrimer Gen 0 to the ionic liquid showed an improvement for CO₂ absorption capability especially at higher temperatures. Among all absorbents tested, 20.0 wt% dendrimer in [bmim][DCA] solution showed the best absorption enhancing effect at 100 ^oC. Dry feed gas mixtures containing 40% CO₂ and 14% CO₂, He balance were used in these studies.