Adsorption characteristics of cyclohexaneon activated carbon fiber material.Influence of the gas-air environment relative humidity

The influence of the gas-air environment (GAE) relative humidity (RH) on adsorption of cyclohexane by commercially available in Ukraine non-woven activated carbon fiber material (ACFM) “Carbapon B-Active” was investigated under dynamic conditions. It is shown that for each relative humidity value in the range of 16-84% the curves of cyclohexane break throught hrougha fixed layer of ACFMin the coordinates ( tпр, ln(c0/cпр–1)) are approximated by straight lines - tпр = A – B·ln(c0/cпр–1), and the Wheeler-Jonas equation can be used to analyze the breakthroughcurves and determine its dependent variables: ACFM adsorption capacity – q0(RH) and the С6H12 vapor adsorption rate constant – kv(RH). It is shown that the presence of water vapor in the GAE does not affect ACFM adsorption capacity up to approximately RH = 35%, and only then gradually decreases with increasing relative humidity; adsorption rate constant kv significantly decreases with increasing RH. In the range of RH 30 – 85% auxiliary empirical equations for the dependent variables of the Wheeler-Jonas equation q0(RH) and kv(RH) are obtained. The adaptation of the Wheeler-Jonas equation for predicting the breakthrough times under real-life conditions is demonstrated by varying its independent variables: mass and adsorbent layer geometric dimensions, C6H12 vapor concentration and GAE relative humidity. The prospects of using a layer of non-woven "Carbapon B-Active" for respiratory protection, in particular, for filtering facepiece respirators, are discussed.