Nor Adilla Rashidi

Development of Novel Low-Cost Activated Carbon for Carbon Dioxide Capture

promising solid adsorbents that can be utilized to capture CO2 due to its numerous benefits, such as inexpensive, easy for regeneration, insensitiveness towards the moisture, high CO2 adsorption capacity at ambient condition, high specific surface area, adequate pore size distribution, high mechanical strength, as well as low in energy requirement (4). Based on the benefits possessed by activated carbon, it has been widely employed in various applications, be it in gas or liquid phase. However, exploitation of the activated carbons in capturing CO2 has not been extensively evaluated. The potential of activated carbon in CO2 capture depends on few criteria such as types of activation method and nature of starting materials, which in turn affects the porosity and surface chemistry of the synthesized activated carbon (5). The chemical activation method includes the ammonia treatment and impregnation technique that have been extensively employed nowadays is uninvited as it imposes hazardous impacts towards the environment and also, results in pore blockage that may possibly lessen the adsorption capacity. Plaza et al. (2) proved that impregnation of activated carbon with amine-based compounds is not a suitable approach for CO2 capture at room temperature, as it reduces the surface area and block the microporous structure that is accountable for physical adsorption process. Specifically, the impregnated activated carbon with polyethylenimine (PEI) solvents which had BET surface area of 90 m 2 /g can only capture CO2 up to 4.9 wt%, as compared to virgin activated carbon that had total surface area of 1,762 m 2

Addition of water in calcium based adsorbent for CO2 adsorption: Experimental and isotherm modelling studies

In this work, a combined process of adsorption and gas hydrate formation is proposed as an alternative approach for the separation of carbon dioxide (CO2) content from gas stream. The objective of this research is to study adsorption isotherms of the CO2 gas onto the synthesized calcium oxide (CaO) via a static volumetric method at 2 °C at a different amount of water ratio (Rw). A large increment of CO2 adsorption was observed on the wetted sample due to formation of CO2 hydrates, particularly at high pressure. The highest adsorption capacity was obtained at Rw of 0.67. The experimental data of CO2 adsorption isotherms for Rw = 0 and Rw = 0.67 are further analyzed by five isotherm models which are Langmuir, Freundlich, Redlich-Peterson (R-P), Toth and Sips. The Freundlich model satisfactorily describes the CO2 adsorption onto the dried sample, whilst the R-P model is best fitted for the wetted sample.