Studies on Selective Adsorption Resins of Mercaptans

It was found that hydroquinone-formaline resin (Hq-F) and its oxidative product, quinone-formaline resin (Q-F) adsorp mercaptanes, cysteine and similar compounds selectively. As an application of this facts we examined the exclusion of the cocoon-like odor caused by mercaptane in brewed products, such as Sake and beer. By measuring the adsorption isotherm in both systems of Hq-F, Q-F and aqueous or alcoholic solutions of ethyl-mercaptane, we have shown that a Hq-F has larger capacity than Q-F in adsorption of mercaptane. The adsorption velocity of the resins was explained by SAKURADA's equation referring heterogenous reaction velocity, and the rate determining step was dependent of the diffusion velocity into them. The desorption of ethyl-mercaptane from the resins was carried out by steam distillation, and the resins were thus regenerated. Under a N2 gas flow the adsorped mercaptanes were almost entirely recovered.