Intelligent design breaks the trade-off between energy efficiency and water flux in ultrafast seawater desalination

Public summary

* A multiscale intelligent design framework is proposed for ultrafast seawater reverse osmosis desalination.

* A bio-inspired module is optimized to achieve a best trade-off between mass transfer and flow resistance.

* Optimized ultrapermeable membrane systems significantly improve desalination energy efficiency.

Abstract

Enhancing the energy efficiency for energy-intensive seawater desalination technologies is imperative to sustainably mitigate water scarcity while reducing carbon footprints. This work presents a transformative advance in reverse osmosis desalination technology by fundamentally redefining the long-standing trade-off between energy efficiency and water production efficiency. Through the synergistic integration of bio-inspired ultrapermeable membrane module with state-of-the-art batch reverse osmosis, we demonstrate unprecedented performance—achieving a specific energy consumption of 1.68 kWh m−3 while delivering an average water flux of 95 L m−2 h−1. This represents a 33%–58% reduction in energy demand and a 5-fold improvement in water flux compared with conventional seawater reverse osmosis desalination plants (2.5–4 kWh m−3 and 15 L m−2 h−1), challenging the prevailing assumption that increased membrane permeability offers only marginal efficiency benefits. This work can further guide the development of advanced membrane materials and energy-efficient desalination technologies, with potential applications in desalination and zero/minimal liquid discharge systems.

Introduction

Global freshwater resources are becoming increasingly scarce. Desalination and wastewater reclamation and reuse through purification are expected to be the primary water resource augmentation technologies in the coming decades.1 Over the past three decades, seawater desalination capacity has increased more than 8-fold, now reaching 100 million cubic meters per day.2 Reverse osmosis (RO) is one of the most advanced desalination technologies currently available, accounting for over 60% of the global desalination market.