Estimation of Activated Carbon Fiber (ACF) Adsorption Capacity and Breakthrough Times using a Predictive Model - Abstract
Activated Carbon Fiber (ACF) has properties that make it a great candidate as a sorbent in respirators against Volatile Organic Compounds (VOCs). Adsorption properties of ACF relevant for the determination of the potential service life, such as breakthrough time and adsorption capacity have been determined experimentally for a number of commercially available ACFs and selected sorbates. However, in order to reduce time and labor intensive testing, we examined here if inputs from an adsorption isotherm equation (Dubinin-Radushkevich or D-R) can be used to predict ACF adsorption capacity and breakthrough time without performing breakthrough experiments. Two rayon-derived ACFs [ACFF 1800 and ACFF 2000] were assessed in this study using toluene, hexane and methyl ethyl ketone (MEK) as adsorbates. Theoretical breakthrough times obtained from D-R isotherm inputs and applying the Wheeler-Jonas equation were obtained and compared with experimental breakthrough times. In general, breakthrough time predictions aligned well with our experimental results. Our data shows that 10% calculated breakthrough times exceeded experimental data in all but three instances. However, the differences between these times were lower than 4.2 minutes and 9.3 minutes for ACFF 1800 and ACFF 2000, respectively when challenged by all three adsorbates. Further research would ideally look at a greater range of concentrations and adsorbate classes and develop necessary correction factors.