CO2 Capture Using Particulate Silica Aerogel Immobilized with Tetraethylenepentamine (TEPA)

CO₂ capture using particulate silica aerogel immobilized with tetraethylenepentamine (TEPA)

Nick Linneen (presenter), Jerry YS Lin, Robert Pfeffer

School for Engineering of Matter, Transport, and Energy

Arizona State University

Tempe AZ 85289

Abstract:           

Post-combustion capture of CO2 using solid amine-based sorbents is attracting significant attention due to their high selectively, reduced corrosive properties, and low energy regeneration requirements. Research has shown that sorbents that have large pore diameter and pore volume generally achieve the highest CO2 adsorption capacities. This is a result of the support's greater potential to retain large amounts of amine, while also allowing effective CO2 transport within the sorbent. We have developed a novel sorbent using particulate aerogel as a support. Aerogel, also known as “solid smoke,” is a high porosity, high surface area, silica-based material that has very large pore volumes and pore diameters compared to other supports. Therefore aerogels can retain large amounts of amine while also maintaining some mesoporosity for effective CO2 transport. By impregnating tetraethylenepentamine (TEPA), which is an ultra-low molecular weight linear polyethylenimine (PEI), into commercially available 10 micron size aerogel (Cabot Corp. Nanogel), we have obtained an adsorption capacity as high as 6.1mmol/g which is very competitive relative to other CO2 sorbents. The aerogel-amine based sorbent was also found to achieve fast kinetics reaching 90% of its equilibrium capacity within the first 10min and also maintaining its adsorption capacity after 10 adsorption/desorption cycles.