Exploration of the Mechanism of Acid Tailing on Strong-Base Ion Exchangers: Modeling and Experiment

• Published in: Industrial & engineering chemistry research 2023-10, Vol.62 (41), p.16875-16885
• Main Authors: Kou, Jingwei, Chen, Chen, Zhang, Jing, Xiang, Houle, Guo, Han, Li, Dan, Wang, Hui, Zhang, Jihang, Yang, Pengpeng, Zhuang, Wei, Ying, Hanjie, Wu, Jinglan
• Format: Article
• Language: English
• Subjects: Separations
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/acs.iecr.3c02467

A new DTSD-S model (combining the ion-exclusion chromatography-Donnan model and two-step dissociation of sulfuric acid) was developed herein to predict C P,SO4 2– and C P,HSO4 – in the resin pores during the adsorption and desorption processes. A comparison of C P,SO4 2– and C P,HSO4 – during the desorption process showed that the tailing phenomenon was affected by the acid concentration. When C H+ was lower than 0.9 mol/L, the predominant species in the resin pores was SO4 2– instead of HSO4 –, which verified that the sulfuric acid tailing was caused by SO4 2–. The results of energy-dispersive spectroscopy and X-ray photoelectron spectroscopy of the resins after adsorption showed the existence of extra S element, which further verified that the existence of SO4 2– was the main factor that caused the acid tailing. Finally, we concluded that the acid tailing was inevitable and suggested that one could recover a high H2SO4 concentration by using a high feed acid concentration.