Enhancing productivity and energy efficiency in vacuum membrane distillation systems

Abstract

This study comprehensively analyzes a multistage vacuum membrane distillation (VMD) system, exploring diverse energy recovery methods and explaining the relationship between operational parameters and system performance. Through an intensive exploration of key parameters the study evaluates critical metrics, including productivity and gained output ratio (GOR). The analysis revealed that at lower feed temperatures, particularly 60 °C or below, layout 2 showcasing optimal GOR. However, a noteworthy shift occurs at temperatures exceeding 60 °C, where layout 3 surpasses the other layouts. At lower pressure levels in the permeate side (60 mbar or below), layout 3 demonstrates higher energy recovery. A reversal occurs at higher pressures, with layout 2 exhibiting the most favorable GOR. For a smaller number of stages, specifically five or less, layout 2 exhibits the highest energy recovery. However, as the number of stages increases beyond five, layout 3 consistently outperforms the others. Finally, layout 3 is found to be optimal for smaller channel depths (20 mm or less), showcasing higher GOR. Conversely, as the channel depth increases beyond 20 mm, layout 2 emerges as the more efficient choice. This study offers valuable insights for researchers aiming to optimize multistage VMD systems, emphasizing the significance of energy recovery layout in achieving enhanced energy efficiency.