SBIR Phase I: Low-Cost High-Efficiency Solar Desalination

The broader impact/commercial potential of this Small Business Innovation Research (SBIR) Phase I award is through the development of a low-cost desalination technology directly powered by sunlight. Combining cutting-edge nanotechnology, concentrating solar power, and innovative and compact design, the technology can convert any saline water or wastewater to potable quality fresh water using sunlight as the only energy source. The research will evaluate a novel reactor design that allows the thermal energy converted from sunlight to be recovered and reused multiple times for desalination and purification of saline water, all in one compact, low cost device. If successful, this technology could provide a low-cost, energy-efficient, and environmentally sustainable solution to a wide range of water challenges: providing reliable and affordable drinking water for communities that lack access to fresh water or reliable power supplies; supplying clean water at off-grid industrial production sites; recovering clean water from municipal and industrial wastewaters; minimizing discharge of contaminants-laden waste streams to the environment. This SBIR Phase I project aims to develop a high efficiency, low cost desalination technology directly powered by sunlight. The research pursues two innovations that greatly enhance the performance of a novel desalination process: nanophotonics enhanced solar membrane distillation (NESMD). First, a novel membrane module design (patent pending) could achieve multi-effect solarthermal membrane distillation in a compact, low-cost module; second, coupling the multi-effect module design with a low-cost solar concentrator would deliver high intensity solar irradiation necessary to drive a multi-effect process while maintaining high membrane flux. The goal is to increase in the gained output ratio (GOR) by a factor of 5. The high GOR value will reduce the specific energy consumption for desalination, and enhance water production rate per irradiated area. Proposed research includes (1) constructing a multi-effect NESMD module that demonstrates multi-stage heat recovery, (2) modeling the nonlinear, and coupled heat, momentum, and mass transfer in the module, (3) determining the effect of solar concentration, and (4) determining the effect of operating conditions and feed water quality. Model simulations will guide design, prototype testing, and optimization, while experimental research results will be used to improve the process model. Technoeconomic analysis will compare the proposed technology with existing desalination technologies. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.