Adsorption characteristics of water vapor on the hypercrosslinked polymeric adsorbent

Abstract

Hypercrosslinked polymeric adsorbent is finding increased application as sorbents for removing the VOCs from gas steam. Due to the competitive adsorption between the water and VOCs, hence, it is important to understand the adsorption characteristics of water vapor on hypercrosslinked polymeric adsorbent. In this paper, the adsorption of water vapor on hypercrosslinked polymeric adsorbent with poly (styrene-divinylbenzene) matrix (HY-1) was investigated and compared with a commercial activated carbon (m-GAC) and activated carbon fiber (ACF). The results showed that HY-1 had minimal uptake of water until P/ P 0 was raised to 0.6, which is an indication of an extremely hydrophobic surface. Moreover, increasing the temperature induced the decrease of the water uptake and a rightward shift in the isotherm heel. The adsorption isotherms of water vapor on three adsorbents were fitted by the Cluster Formation Induced Micropore Filling model (CIMF model). The results indicated that the experimental data can be well-fitted by CIMF model. Based on this semiempirical modeling, the adsorptive contributions of primary sites and micropores were estimated qualitatively. In addition, the effect of water vapor on the adsorption of benzene onto three adsorbents was investigated. The breakthrough time of benzene on HY-1 decreased by 10.4% even if the relative humidity was 80%, while that of m-GAC and ACF decreased by17.2% and 38.9%, respectively. Therefore, HY-1 would be a particularly efficient and competitive adsorbent for VOCs recovery from the humid gas streams.