Our Research Efficient multi-stage distillation
Principal Investigator
Gang Chen
- Carl Richard Soderberg Professor of Power Engineering
- Department of Mechanical Engineering
Gang Chen is the Carl Richard Soderberg Professor of Power Engineering at the Massachusetts Institute of Technology (MIT) and former head of the Department of Mechanical Engineering at MIT. He conducts research in heat, energy, nanotechnology, and water. He received an honorary Doctor of Science from the University of Hong Kong. He is a foreign member of the Chinese Academy of Science, an academician of the Academia Sinica, a fellow of the American Academy of Arts and Sciences, and a member of the US National Academy of Engineering and a member of the U.S. National Academy of Science.
Challenge:
Can we make thermal desalination technology more competitive in efficiency than reverse osmosis?
Research Strategy
- Build a novel multistage distillation device configuration that minimizes the temperature drop across each stage
- Conduct rapid device prototyping coupled to modeling and simulation
Project description
Membrane distillation (MD), which combines thermal distillation with membrane separation, has attracted growing interest for desalination. Multistage MD systems can reuse the latent heat released during condensation, achieving gain-output ratios (GORs) of approximately 8–10. Despite this improvement, their efficiency remains significantly lower than that of reverse osmosis (RO), which operates within about a factor of two of the thermodynamic minimum energy requirement determined by the Gibbs free energy of separation. Thermodynamic analysis shows that the second law efficiency of a multistage thermal desalination process could, in principle, match that of an ideal RO system. Current multistage vacuum-gap membrane distillation (MVGMD) systems typically require temperature drops of about 5–10°C per stage, substantially larger than what is thermodynamically necessary (about 0.4°C). To address this limitation, the principal investigator has developed a novel multistage vacuum distillation (MVD) configuration designed to operate with much smaller temperature differences between stages. This approach could achieve ROlike second-law efficiencies while utilizing low-grade waste heat or renewable energy. The proposed project will experimentally validate the performance of these MVD systems, laying the groundwork for highly efficient desalination and other thermal separation applications.
Additional Details
Impact Areas
- Water
Research Themes
- Water Purification & Desalination
Year Funded
- 2026
Grant Type
- Seed Grant
Status
- Ongoing