The preparation and investigation of ionic functional resins for deep dehydration of toluene

Abstract

Toluene is a solvent and raw material widely used in industrial production. Reducing the water content of toluene to less than 10 mg/kg is of significant importance in fine chemicals. In this study, different ionic functional resins containing strong hydrophilic sulfonate groups were synthesized. These ionic functional resins exhibit an exceptional depth of toluene dehydration and an extremely high water absorption capacity. The most effective hydrogen functional resin has a water adsorption capacity of 679.7 mg/g, which is more than 2.5 times of 3A molecular sieve, and can dehydrate toluene from 180 mg/kg to less than 3 mg/kg. The specific surface area and pore size distribution of the resins were analyzed by nitrogen adsorption and desorption methods, and results show that these resins are mesoporous materials. The multilayer adsorption mechanism of the ionic functional resins was determined by fitting the adsorption isotherms using a Modified Dent model. The effects of contact time, oil-agent ratio, regeneration temperature, and number of regenerations were also investigated, and fixed-bed penetration curves were obtained to provide data for practical industrial applications. The results show that low-temperature drying at 80 °C is sufficient to regenerate the ionic functional resin. Finally, competitive adsorption studies with toluene and water reveal that the resin exhibit a higher affinity for water than for toluene.