Objective
The overall objective of the project is to develop a technology for military use which is capable of harvesting drinking water from the air in austere and remote environments without regard to geography or climatic conditions. This technology would enable the military to make available drinking water at the point of use for all of its operations including Forward Operating Bases, stationary bases, as well as to the administrative facilities in a simplistic and cost-effective manner. The environmental benefits accruing from this project are low energy requirement and elimination of plastic bottles in supplying the drinking water to the military. This will greatly reduce the incidence of ocean plastics. Reduction in plastic use would also promote sustainability and reduced the use of natural resources including oil.
Technology Description
The water harvesting technology for the project is based on Ion Deposition Membrane (IDM) technology. The key feature of the technology is the use of a set of two inert membrane leaves produced from polytetrafluoroethylene film with modified pore structure through proprietary ion deposition. These IDM leaves are separated from each other by circulating liquid crystal carrier. The modified pore structure on both of these IDM leaves generates selective passage for only the water molecules, in one case from the air, and the second case from the carrier. The small pressure drop across the first membrane provides the driving force required for water adsorption into the first IDM and its subsequent transfer to the carrier. Re-adsorption of water molecules from the carrier, membrane saturation, and slight cooling is utilized for recovering drinking quality water from the carrier at the second membrane. The rate of water harvesting is dependent upon the relative humidity, the surface area of the IDM leaves, and the circulation rate of the carrier. The entire process requires less than 10 percent of energy when compared with harvesting water using condensation. The purity of water is also significantly higher. The technology can be operated over a large range of water from 100 liters per day to 2000 liters per day in a single module. This allows the technology to be customized for all of the military applications. This technology holds a key to making available freshwater to the military from the single largest source which is air, and which is continuously being naturally replenished.
Benefits
With the inherent advantage of the technology with scaling from low to high capacity, the low costs associated with its manufacturing and minimal energy requirements will result in the production cost of a fraction of a penny for the liter of drinking water from this IDM technology. This system would provide the military with the ability to harness freshwater in any austere or remote environment thereby eliminating the biggest payload of drinking water it carries from place to place and all costs associated with it. Even more significant is the simplicity and ease of adapting the technology which would greatly facilitate the early transition of the technology into all facets of the military operations. Reduction and/or elimination as well as dependence on plastic bottled waters will also be seen as a big step by the military toward improving the environment and toward sustainability.