Application of Ideal Adsorption Solution Theory (IAST) for Investigation of Separation of Carbon Dioxide / Nitrogen Gases on Nitrogen-doped Porous Carbon Synthesized from Nano-polyaniline

In this study, nitrogen-doped porous carbon was prepared using a nitrogen containing polymer (polyaniline) as a precursor with KOH activation at activation temperature of 800°C. The porous structure of polyaniline and synthesized adsorbent were analyzed with atomic force microscopy (AFM), N2 adsorption-desorption isotherm, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The adsorption of CO2 and N2 by nitrogen-doped porous carbon were measured and correlated Sips model. The BET surface area and CO2 adsorption of prepared adsorbent (at 298K and 1ba) was achieved 723 m2/g and 1.90 mmol/g, respectively. The selectivity of CO2 over N2 (CO2: N2 =50: 50, 298 K, 1 bar), predicted by the ideal adsorbed solution theory (IAST) model, was achieved 3.02. The isostrict heat of adsorption was calculated by using Clausius-Clapiron equation and the results confirmed the exothermic nature of adsorption for both gases. Also, the higher value of heat of adsorption CO2 than N2, showed the stronger interaction between CO2 molecules with the nitrogen-doped porous carbon surface. Results obtained from gas adsorption and heat of adsorption proved the suitability of nitrogen-doped carbon in cyclic processes such as the PSA process.