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There are several possible methods by which amine groups can be grafted on the surface of activated carbon (AC) to improve their capacity for CO 2 adsorption. Ethylenediamine and diethylenetriamine were selected as amino compounds for anchoring on the surface of an oxidized AC. Oxidation of AC was carried out by concentrated nitric acid. For each amino compound, two "in-solvent" and "solventfree" methods with a number of grafting times were studied. Nitrogen adsorption-desorption at 77 K and proximate and ultimate analysis were used to determine physical and chemical characteristics of the samples. Temperature-programmed (TP) CO 2 adsorption test from 30°C to 120°C were performed to investigate the effect of modification on CO 2 capture. The modification clearly had a negative effect on the textural characteristics of the samples, so the samples showed a less CO 2 uptake at lower temperatures. However, the decrease of capture capacity with increasing temperature is to somewhat softer for amine-grafted samples, so that they have a capacity comparable to the parent sample or even more than that at elevated temperatures. This property may give the new adsorbents this opportunity to be used at flue gas temperature with a higher efficiency. CO 2 capture capacity per unit surface area of all the amine-modified samples, however, was significantly improved, compared to the parent sample presenting a great influence of amino groups on the CO 2 capture capacity. Moreover, the used amine compounds and grafting methods were compared in terms of adsorbent characteristics and CO 2 uptake curves. Cyclic adsorption-desorption tests showed a satisfactory regeneration for the modified samples.

Adsorption dynamics of single and binary vapor systems on the activated carbon bed were studied by using acetone, methylethyketone (MEK), benzene, and toluene. Relationships between the equilibrium adsorption capacity and the characteristics of vapors such as molecular weight, density, boiling point, vapor pressure, molecular diameter, and polarity index were also investigated. From breakthrough experiments, toluene had the strongest affinity with activated carbon in the single and binary vapor systems. The shape of the breakthrough curves of vapor with higher affinity in the binary system was similar to that of the single vapor. On the other hand, the vapor with lower affinity showed a roll-up phenomenon, but the level of roll-up became lower and wider with the increase in fraction in the binary system.

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