(118f) Hollow Fiber-Supported Designer Ionic Liquid Sponges for Post-Combustion CO2 Scrubbing

A proof of concept study for a new type of carbon capture system is considered for post-combustion CO2 capture based on porous hollow fiber sorbents with ionic liquids sorbed in the cell walls of the fiber. This study proves that delicate morphological features in the open-celled porous wall can be maintained during the infusion process. Mixtures of task specific ionic liquid (i.e. [BMIM][Tf2N]) and superbase (i.e. DBU) were loaded into polyamide-imide (PAI) fibers by a so-called two-step non-solvent infusion protocol. In the protocol, methanol carries ionic liquids into the pore cell walls of hollow fibers and then hexane carries superbase to create an efficient CO2 sorbent. Our ionic liquid/superbase impregnation technique overcomes a serious increase in mass transfer resistance upon reaction with CO2, thereby allowing its large scale utilization for post-combustion CO2 capture. The investigation on the effect of different pore former additives (different molecular weights of polyvinylpyrrolidone, lithium nitrate, and their mixtures) suggested a potential solution to produce highly interconnected open cell pore structures of PAI hollow fibers.  Lastly, a lumen side barrier layer was successfully formed on the bore side of neat PAI fibers by using a mixture of Neoprene® with crosslinking agents (TSR-633) via a post-treatment process. The lumen layer will enable heat removal from the fiber sorbents during their application in rapid thermal swing cycling processes.