Comparison of Adsorption Capacity of Amine Modified Activated Carbon from Stone Apple for CO₂ Capture

Increase in atmospheric carbon dioxide concentration due to industrial activity of more than a century has led to the problem of global warming, which hints at a catastrophic climatic consequence for the whole world. The reduction in the emissions of greenhouse gases possesses a challenge in addressing the issue of climate change. Adsorption is considered as a competitive solution. This present research focus separation of post combustion capture carbon dioxide from flue gas by adsorption mechanism as it needs less energy and amine modified activated carbon prepared from stone apple can be used as solid adsorbent. Two different amine solution i.e. Ethylene Diamine (EDA) and Tetra Ethylene Penta Amine (TEPA) were used as impregnating agent for activated carbon with impregnation ratio 0.4 (EDA-AC (0.4) and TEPA-AC (0.4)). Further the amine impregnated activated carbons were characterized using various techniques such as Proximate Analysis, Ultimate Analysis, Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS), Fourier Transform Infrared spectroscopy(FTIR), BET surface area analyzer, Thermo Gravimetric Analysis (TGA), X-Ray Diffraction (XRD). From ultimate analysis, the percentage of nitrogen in the raw precursor, activated carbon, EDA-AC(0.4) and TEPA-AC (0.4) were 2.7%, 1.8%, 8.5% and 6.8%. respectively. From BET surface area analysis the surface area of raw precursor, activated carbon, EDA-AC (0.4) and TEPA-AC (0.4) were 60 m²/g, 1050 m²/g, 814 m²/g and 695 m²/g respectively. Remarkable increase in the adsorption capacity was observed and the maximum adsorption (37.8 mg/g) was found in Ethylene diamine impregnated activated carbon having impregnation ratio 0.4 (EDA-AC(0.4) at 298.15 K and 1 atm having break through time of 215 min.