(561e) Entropic Enhancement of CO2 Capture Using Nanoparticle Ionic Materials (NIMs)

Authors: 
Lin, K. A., Columbia University
Park, Y., Columbia University
Park, A. H. A., Columbia University


A newly developed material, Nanoparticle Ionic Materials (NIMs), is synthesized with different molecular weight of counter ions (600~2000 polyetheramine) and silica core sizes (7, 12 and 22 nm). A series of analytical tools including TGA, TEM, ATR-IR and NMR are employed to characterize thermal stability, core/counter ions fractions, dispersion, and structural and chemical configuration of synthesized NIMs. It has been hypothesized that the ionic bonds located in corona chains can contribute electrostatic repulsion between corona chains and as a result increase the free volume within the system. Therefore, CO2 capture by NIMs can be maximized by controlling both enthalpic and entropic effects. In this study, we focus on the CO2 capture enhancement via the entropic effect through the investigation of the effect of increased free volume on NIMs' CO2 capture capacity. The experimental setup consists of a temperature and pressure controlled reactor system equipped with a pressure transducer and the effects of temperature (25?65ºC) and partial pressure of CO2 (0.07?0.34MPa) are investigated. It is found that more than 95% of CO2 absorption in NIMs is achieved during the first 20 minutes and the equilibrium is generally reached in about 50 minutes at 35 ºC, PCO2 = 0.31 MPa. At the equilibrium, 1 kg of the NIMs sample can capture about 0.16 mole of CO2. It is also found that temperature and partial pressure of CO2 can significantly affect the viscosity of NIMs.