Research on heat and mass transfer characteristics of vacuum membrane distillation device for sulfuric acid solution

In the context of peak carbon and carbon neutrality, a vacuum membrane distillation system device made from the polytetrafluoroethylene (PTFE) hydrophobic membrane, is proposed to achieve resource recovery of industrial sulfuric acid wastewater. Multiple condition experiments were conducted using sulfuric acid solution, the heat and mass transfer performance were explored, and the results indicated that: the excellent freshwater was obtained with a lower conductivity of 95 μS·cm −1 after 24 h of stable operation. Furthermore, increasing feed concentration decreased the Re , Nu and Sh , weakened the heat and mass transfer process and reduced the transmembrane driving pressure difference. Increasing feed temperature and feed flow rate increased the Re , Nu and Sh , enhanced the heat and mass transfer process and increased transmembrane driving pressure difference. Increasing permeate side pressure might slightly improve the heat and mass transfer process, but the transmembrane driving pressure difference would be reduced directly. Finally, the prediction models for the heat transfer coefficient, mass transfer coefficient and membrane flux under different operation conditions were obtained through multiple linear regression method. These research results lay the foundation for the future optimization design and intelligent operation and maintenance of VMD system. • A vacuum membrane distillation system of sulfuric acid solution was focused on. • High feed temperature and feed flow rate enhance mass and heat transfer. • High feed concentration and vacuum side pressure weaken mass and heat transfer. • Prediction models were obtained through multiple linear regression method.