I-Corps: Nanophotonics Enabled Solar Membrane Distillation

William Marsh Rice University, Houston TX

Investigators

Abstract

The broader impact/commercial potential of this I-Corps project is addressing the increasing demand for sustainable water purification and cost-effective phase separation with an energy-efficient, economical, portable and scalable solution. More than a billion people around the world lack access to clean drinking water. Most of the existing technologies for water purification and phase separation mainly use energy from conventional fuels increasing their operating cost and limiting their application. The proposed technology of Nanophotonics-enabled Solar Membrane Distillation (NESMD) uses solar energy to vaporize water and potentially other liquids of interest. NESMD system is energy-efficient, portable and can be scaled in size making it suitable for household, commercial and industrial water purification. Cost-effective phase separation with NESMD can be attractive for petroleum and related industries as well. This I-Corps project focuses on electricity-free water purification and phase separation. Nanophotonics-enabled Solar Membrane Distillation (NESMD) system consists of a polymer membrane coated with light-absorbing carbon-based nanomaterials which efficiently absorb incident sunlight. The capability of converting light into heat within a thin layer on top of a semipermeable membrane allows an efficient local conversion of liquid to its vapor phase. This membrane can be used in contact with saline/polluted water or a mixture of organic solvents allowing the heat from the absorbed sunlight to induce vaporization through the membrane separating the liquid of interest from non-volatile components such as salts, heavy metals, bacteria or other liquids. Proof-of-concept lab-scale studies of the NESMD system show efficient water purification with more than 99.5% salt rejection. Through this I-Corps project the team wants to further assess and investigate the value of this technology for water purification and phase separation market.