Volumetric Absorption Concentrated Solar Thermal Zero Liquid Discharge Desalination
Problem statement
The National Renewable Energy Laboratory is looking to develop a system to desalinate seawater, using concentrated solar power from a two-stage heliostat, that results in zero liquid discharge. Current methods are expensive, inefficient, and difficult to implement. Coastal regions in the United States, that have access to readily available seawater and sunlight, would greatly benefit from the development of this new desalination system. Solar desalination is a technique that uses concentrated solar energy to remove salt and other solids from seawater [1]. The solar energy boils the seawater, turning it into condensate. Once the solids and foreign particles have been removed from the seawater, the condensate can be cooled and harvested as freshwater water for human use. Coastal areas that are experiencing drought and a shortage of potable water would benefit from the use of solar desalination, as it is energy-efficient, environmentally friendly, and cost-effective. In addition, this method of distillation could be used for irrigation wastewater treatment [1]. This problem will be analyzed through four main tasks to achieve the goal. First, the properties of the sunlight and the radiation energy concentrated from the heliostat will be investigated and used to design a beam-down system to direct this energy at the seawater mixture. Second, the characteristics of the seawater and its interaction with the radiation energy from the Sun will be investigated to determine the dimensions of the tank holding the seawater to both ensure sufficient energy is reaching all parts of the mixture and minimal energy is reflected back out of the container. The volume of water to be processed each day must be estimated, which also plays a role in determining the tank dimensions. Third, the mechanical system will be designed to ensure adequate strength, rigidity, and protection from harsh and corrosive elements. This will be done by analyzing materials’ interactions with the environment and calculating the needed strength of the structural materials to create an economically efficient design. Finally, the process of how the salt will be removed from the tank as well as how maintenance and adjustment will be performed will be studied to ensure minimal operator dependency and downtime are required. References: [1] Moss, Dough & Scheer, Roddy. “Can Solar Desalination Slake the World’s Thirst?”. Scientific American. September 2015
Team members
Abby Warren – leader
Ethan Padgett – communicator
Charles Donovan – accountant
Nick Thull – admin
Client
Ty Neises, NREL