(11c) High Swing Capacity MIL-101(Cr) Fiber Sorbents for Sub-Ambient CO2 Capture Via RCPSA

A challenge facing CO₂ capture from flue gas via adsorption is the high cost of adsorbent materials, a phenomenon partially driven by low operating capacities leading to massive sorbent requirements. Increasing operating capacity can be accomplished by advances in sorbent materials, cycle design, and process design, giving the sorbent more capacity or making it operate more efficiently. This talk focuses on designing new structured sorbents using metal organic framework (MOF) materials to enable high capacity via a sub-ambient rapidly cycled pressure swing adsorption (RCPSA). We have found flue gas compression and cooling is counterintuitively energy efficient when extensive heat integration and energy recovery is utilized, and this concept enables high operating capacity for a variety of MOF sorbents. Current technoeconomic estimates reveal parasitic loads as low as 19% and total costs of CO₂ as low as 37$/tonne.

In this talk, after a brief review of the sub-ambient RCPSA process flow sheet, we will discuss methods of incorporating MIL-101(Cr) into fiber sorbent contactors via direct spinning. Sub-ambient CO₂ isotherms show MIL-101(Cr) may be capable of swing capacities as large as 10 mmol/g, making it an ideal material for sub-ambient RCPSA. Incorporating this material into a fiber sorbent contactors make possible order of magnitude lower pressure drops as well as enabling thermal management, which increases sorbent utilization. Phase change material incorporation into the fiber sorbent during spinning, and its effectiveness as thermal modulation will be presented. The talk will focus on the application of these fibers to capturing CO₂ from simulated flue gas, and will include analysis of breakthrough curves and preliminary cyclic results. These fiber sorbents containing high operating capacity sorbent materials help to support the case for applicability of the novel process design.