Adsorption capacity and thermal effect of adsorbents for oil vapor with humidity

Abstract

As the standards for emissions of organic waste gas become increasingly strict, the competitive adsorption of water vapor and organic waste gas is becoming the hot spot of research on treatment of organic waste gas. Therefore, three adsorbents (AdsFOV-1, AdsFOV-2 and AdsFOV-3) were used for the research, and their adsorption capacity and thermal effect were investigated through the static adsorption to the vapors of n-hexane, gasoline and water after structural characterization. In addition, dynamic adsorption experiments were performed with the vapors of n-hexane and gasoline under different relative humidity conditions, so as to study the influence of relative humidity on adsorption effect and temperature rising curve, as well as the stability of cyclic adsorption. Meanwhile, the kinetics behavior of the adsorption process was judged by kinetic fitting. The results show that: the adsorption capacity of the three adsorbents to the vapors of n-hexane and gasoline decreases with the increasing of relative humidity, but the thermal effect of adsorption becomes more obvious. Besides, AdsFOV-1 and AdsFOV-2 have good cyclic adsorption performances, specifically, when the inlet vapor mass concentration is set to 25 g/m3, the outlet vapor mass concentration of the adsorption tower can meet the emission requirements of less than 80 mg/m3. Further, the adsorption kinetics behavior of the three adsorbents on the vapor of n-hexane is consistent with the Bangham dynamic equation, which means the adsorption rate is mainly controlled by the pore diffusion. In general, the research results could provide theoretical basis for the treatment of industrial organic waste gas with high humidity.

Keywords

• humidity
• adsorption breakthrough curve
• adsorption heat
• adsorption kinetics
• low concentration emission