Investigating Cryodesalination As a Low-Energy and Affordable Solution to Freshwater Scarcity

The 21st century has seen numerous breakthroughs across a wide multitude of fields including, but not limited to, science, technology, mathematics, and medicine. As beneficial as these breakthroughs have been, the means by which they were achieved have devastating impacts on the climate. Climate change is nothing short of a global catastrophe, and the consequences of such are exacerbated in low income and rural communities. This creates an unprecedented disaster where the technologies created to combat climate change are unable to aid those most vulnerable to its impacts. One of these issues is the lack of freshwater access in less affluent regions of the world. The solution to such is desalination; however, current methods are expensive, require immense infrastructure, and are highly energy intensive. To address this dilemma, a new method of desalination must be studied, one that is affordable, requires little to no infrastructure, and is energy efficient. CryoDesalination has the potential to meet all of these requirements by utilizing the simple fact that salt water will freeze at a slightly lower temperature than freshwater. As the water approaches freezing, the ice formed initially will be fresher than the brine left behind. The simplicity in theory is matched by the simplicity in materials, utilizing an Igloo cooler as an insulated housing, copper cups as a vessel for heat transfer, and acetone as a coolant. The salt water is transferred into copper cups and placed in an acetone bath within the Igloo Cooler. Dry ice is periodically dropped into the acetone to facilitate the cooling and reach the desired freezing point quicker. Recent tests have shown roughly a 25% decrease in salt content between the freshwater and initial salt water feed in an hour. Larger decreases were achieved in the past, albeit using a model with more expensive and energy intensive materials. The current results are promising; however, the cooling rate and overall freshwater yield are not enough to be scaled for large quantities of feed salt water. Future iterations need to be automated to improve accuracy of measurements and allow for more consistent separation of freshwater from the salty brine.