Vilavanan

Desalination (English: desalination; desalinization or desalinisation) refers to various processes that remove salt and other minerals from water. Simply put, the process of removing salts and minerals is also called desalination, such as soil desalination.

Saltwater is converted into freshwater for human consumption or irrigation by desalination. Sometimes, edible salt is produced as a byproduct of this process. It is used in ships and submarines. In areas where fresh water availability is limited or decreasing, attention is now focused on desalination to provide cheap fresh water.

Large-scale desalination typically requires more energy with special basic facilities, increasing its cost compared to rivers or land-based fresh water.

The largest desalination plant in the world is Jebel Ali Plant (Stage 2) in the United Arab Emirates. It is a dual-purpose unit that uses multi-stage flash distillation and can produce 300 million cubic meters of water per year. In comparison, the largest desalination plant in the United States is located at Tampa Bay, Florida, operated by Tampa Bay Water, which started desalination of 34.7 million cubic meters of water per year in December 2007. The Tampa Bay Plant operates at only 12% of Jebel Ali's production as of January 17, 2008, according to a Wall Street Journal article that wrote, "According to the International Desalination Association, there are over 13,080 desalination plants worldwide producing more than 12 billion gallons of water per day."

Methods

The traditional process used in these plants is vacuum distillation - essentially heating water under low atmospheric pressure and thus achieving a lower temperature. This happens because liquids boil only when the vapor pressure equals the surrounding pressure, and vapor pressure increases with temperature. As a result, energy is saved due to lower temperatures. Multi-stage flash distillation, which is an advanced distillation method, was responsible for 85% of global production in 2004.

Reverse osmosis technology uses membranes as a competitive process for desalination. Membrane processes use semi-permeable membranes and pressure to remove salt from water. Reverse osmosis plants typically use less energy than thermal distillation, resulting in a decrease in the overall cost of desalination over the past decade. However, desalination will remain an energy-intensive process, and future costs will depend on both energy prices and desalination technology.

Importance and Criticism

Cogenration
Cogeneration is a process where excess energy generated during electricity production is used for another purpose. In the context of desalination, cogeneration involves converting seawater or brackish water into potable water by an integrated or "dual-purpose" unit, which uses the desalination process to