Estimation of activation energy for desorption of low-volatility dioxins on zeolites by TPD technique

Adsorption would be one of the most potential technologies for removal of dioxins from waste gas, but no equilibrium adsorption information of dioxins on adsorbents is available because of their low volatility. In this work, seven kinds of high silica zeolites such as Ag+-zeolite, Fe3+-zeolite, Cu2+-zeolite, Al3+-zeolite, zeolite, Ca2+-zeolite and Na+-zeolite, were prepared. The temperature-programmed desorption (TPD) technique was used to estimate desorption activated energy of dibenzofuran (non-chloro dioxins) on the high silica zeolites. Results showed that the peak temperatures of the TPD curves of dibenzo-p-furan on the zeolites, the Ag+-zeolite, the Fe3+-zeolite, the Cu2+-zeolite, and Al3+-zeolite were higher than those of dibenzo-p-furan on the Ca2+-zeolite and the Na+-zeolite at same heating rate. The desorption activated energy of dibenzo-p-furan on the Ag+-zeolite, the Fe3+-zeolite, the Cu2+- zeolite, and Al3+-zeolite were also higher than those of dibenzo-p-furan on the zeolite, the Ca2+-zeolite and the Na+-zeolite. (C) 2002 Elsevier Science B.V. All rights reserved.