Adsorption Characteristics and Property Analyses of Activated Carbon Adsorbent Impregnated with Basic Solutions

The $H_2S$ adsorption characteristics and property analyses of granular activated carbon adsorbent impregnated with basic solution such as NaOH, KOH, and $(CH_2CH_2OH)_2NH$ were investigated. The concentrations of NaOH and KOH reagent ranged over 1 to 5 M, The concentration of $(CH_2CH_2OH)_2NH$ was in the range of 0.1 to 1 M. Adsorption temperature($25{\sim}45^{\circ}C$) and adsorbate ($H_2S$) concentration (18.23 mg/L) were applied. The experimental results showed that the BET surface area of activated carbon impregnated with KOH decreases from $1,050\;m^2/g$ to $750\;m^2/g$, and the acidity of activated carbon impregnated with NaOH decreases from 0.541 meq/g-AC to 0 meq/g-AC, as the concentration of basic solution increases, while the pH of impregnated activated carbon increased from 9.54 to 10.94 for three basic solutions. It was also found that the $H_2S$ adsorption equilibrium capacity of activated carbon impregnated with NaOH, KOH, $(CH_2CH_2OH)_2NH$ increased with increasing temperature and $H_2S$ adsorption equilibrium capacity of the activated carbon impregnated with diethanolamine was much higher than other cases. At adsorption temperature of $45^{\circ}C$, the $H_2S$ adsorption equilibrium capacity of impregnated activated carbon was 2.0~3.3 times lager than that of pure activated carbon.

염기성용액으로 첨착시킨 활성탄의 물성분석 및 흡착특성

본 연구에서는 NaOH, KOH, $(CH_2CH_2OH)_2NH$ 등의 염기성용액으로 첨착(함침)시킨 활성탄의 물리.화학적 특성을 분석하고 H2S 흡착특성을 고찰하였다. 실험변수로는 흡착온도($25{\sim}45^{\circ}C$), 흡착질인 황화수소 가스농도(18.23 mg/L) 등이 적용되었다. 첨착시약으로 사용된 NaOH, KOH 용액의 농도는 1~5 M, $(CH_2CH_2OH)_2NH$ 용액의 농도는 0.1~1 M 범위내에서 적용되었다. 실험결과, 첨착액의 농도가 증가할수록 KOH로 함침시킨 활성탄의 BET 표면적은 $1,050\;m^2/g$에서 $750\;m^2/g$로 감소하였고, NaOH로 함침시킨 활성탄의 표면산도는 0.541 meq/g-AC에서 0 meq/g-AC으로 감소한 반면, pH는 9.54에서 10.94로 증가하는 것으로 밝혀졌다. 또한 첨착활성탄의 $H_2S$ 평형흡착능은 디에탄올아민으로 첨착시킨 경우에 가장 높았으며, 평형흡착능은 흡착온도에 비례함을 보였다. 흡착온도가 $45^{\circ}C$일 때 비첨착활성탄에 비해 2.0~3.3배 높은 수준의 H2S 평형흡착능을 보여 주었다.