Joule-heating membranes: Do they really work for membrane distillation processes?

• Developed a validated model for Joule-heated membrane distillation (JHMs). • Identified system-level limits, not membrane flaws, as performance barriers. • Achieved 2-3 × reduction in temperature polarization using JHMs. • Demonstrated modest flux gains due to unoptimized thermal integration. • Proposed strategies for scalable, energy-efficient JHM-MD system design. This study critically evaluates the effectiveness of Joule-heated membranes (JHMs) in membrane distillation (MD) processes. Using a Nusselt-based mathematical model and experimental validation, we assess whether JHMs can significantly enhance mass transfer and energy efficiency in MD systems. Our results demonstrate that although JHMs do reduce temperature polarization by 2-3 times compared to conventional MD, the overall flux gains remain modest under standard configurations due to limitations in system design, such as uninsulated tanks and insufficient heat localization. The findings suggest that the limitations are not inherent to the JHMs themselves, but rather stem from suboptimal system integration. With targeted improvements in module insulation, flow configuration, and coating materials, JHMs hold promise for scalable and energy-efficient water treatment applications.