HWAHAK KONGHAK, Vol.22, No.2, 73-81, April, 1984
γ-Alumina로부터 흡착질의 열탈착에 관한 연구
Thermal Desorption Study of Adsorbates from γ-Alumina
초록
흡착온도, 20 ℃에서 Gas Chromatograph를 이용하여 benzene, cyclohexane, methylalcohol, ethylalcohol, n-propylalcohol 및 iso-propylalcohol을 각각 흡착시킨 γ-alumina 표면에 대하여 열탈착을 연구하였다. 흡착제 를 일정승온율（5∼15 ℃／min）로 20 ℃에서부터 350 ℃까지 승온시키면서 탈착되는 물질을 T.C.D로 감지하였다. 이때 나타나는 탈착곡선으로부터 γ-alumina표면에서의 활성점과 온도상승에 의한 탈착상의 거동 및 흡착제-흡착질간의 상호작용 등에 대하여 조사하였으며, 곡선의 최대점의 온도(Tm)를 이용하여 탈착의 속도론적 인자인 탈착활성화에너지(Ed)와 빈도인자(Ko)를 구하였다. 알코올류 에 대한 탈착곡선으로부터 γ-alumina 표면에 성질이 다른 2가지의 활성점이 존재함을 확인할 수 있었다.
γ-alumina에 대한 cyclohexane의 화학흡착은 일어나지 않았다. 실험결과 흡착속도는 피복률（θ）에 대하여 1차 라고 볼 수 있었다.
γ-alumina에 대한 cyclohexane의 화학흡착은 일어나지 않았다. 실험결과 흡착속도는 피복률（θ）에 대하여 1차 라고 볼 수 있었다.
Thermal desorption has been studied or γ-alumina which adsorbed adsorbates, such as benzene, cyclohexane, methylalcohol, ethylalcohol, n-propylalcohol and iso-propylalcohol, separately at 20 ℃ with Gas Chromatographic apparatus. As the temperature of adsorbent was raised from 20 ℃ to 350 ℃ with the constant heating rates （5-15 ℃/min）, the species on adsorbent surface were desorbed, and thermal conductivity detector was employed to monitor the desorbate in effluent gas. The thermal desorption chromatogram was investigates to obtain the information about the active sites, behavior of desorbed phase with increasing temperature and the adsorbate-adsorbent interaction. By means of the temperature at peak maximum, Tm, the desorption kinetic parameters, e.g., activation energy of desorption and frequency factor were determined.
It was found that γ-alumina had two kinds of active sites different in their property for alcohols. Experimental results represented that the desorption rate was first order with respect to the surface coverage.
It was found that γ-alumina had two kinds of active sites different in their property for alcohols. Experimental results represented that the desorption rate was first order with respect to the surface coverage.