Removal Of Trace Water From Anisole By Adsorption

Industrial production of enriching isotope10B is based on the separation oftrifluoride-anisole complex by chemical exchange distillation. Trace water in anisoleaffects the quality of downstream products, it should be dehydrated to a H2O contentof0.003%to0.005%(weight percent). So the dehydration of anisole becomes a veryimportant problem to be solved.In this paper the adsorption performance of trace water in anisole on3A and4Amolecular sieves were studied.Firstly, adsorption isotherms for3A and4A molecular sieves were measuredrespectively at different temperatures. The data were fitted well with the models ofLangmuir and Freundlich. According to the parameters, the results indicate that theadsorptive amount decrease with the temperature raising. The results are in agreementwith tendency.On the base of static adsorption, adsorption kinetics for3A and4A molecularsieves were measured at298k. The data were fitted well with the models ofpseudo-second-order model.The adsorption dynamic characteristics of fixed-bed for3A and4A molecularsieves were also investigated. The effects of height of bed, flux and initialconcentration were studied. The results showed that in each set of experiments, theconcentration of H2O in the effluent after adsorption on3A molecular sieve is10-25ppm, and the concentration of H2O in the effluent after adsorption on4A molecularsieve is13-26ppm.Lastly, Thomas model and Yoon–Nelson model were applied to fixed-bedexperimental data. The results show that Yoon-Nelson and Thomas models weresuitable for the adsorption process. The research results provided a proper basis forfurther industrial uses, and also are an intuitive tool of industrial design.