Evaluation of organic vapor breakthrough time of an activated carbon bed containing moisture by Wood’s estimation model using the Wheeler-Jonas equation

The breakthrough time estimation model reported by Wood makes use of the Wheeler–Jonas equation, the Dubinin–Radushkevich equation and previous research progress regarding gaseous adsorption of compact activated carbon beds. The estimation model can take into account the effects of temperature and relative humidity in the environments of activated carbon beds and type of organic vapor as adsorbates. In using the model, the determination of several constants or coefficients of its equations is important, and Wood also reported several empirical formulas for the constants or coefficients. In this study, we carried out an estimation of the breakthrough time by the model, and examined problems regarding its empirical formulas and its effectiveness with reference to the experimental data of breakthrough times. In particular, the determination of affinity coefficient of organic vapor βOV is most significant in the model. The values of βOV calculated by the empirical formula presented by Wood are liable to be small for application of recent activated carbon products for gas adsorption or gas respirators in Japan, and the formula requires further improvement for exact estimation by the model.