For the survival of humans, animals industries and agricultural sector, fresh water has always been a vital commodity. With the increase in each of the above factors makes an increase in its supply in the future important. As it is becoming a scarce commodity. There are various seawater technologies that have come up which aided significantly in achieving the objective.
Statistically the marine makes up 97% of the global aqua storage. Whereas the locked amount by the glaciers and ice caps amount to 2% of the total supply. The percentage available for human use is about 0.5%. Supplied by lakes and rivers. Water from the sea is neither suitable for consumption by humans nor industrial use. There by desalination being considered as an important alternative for sourcing out fresh water.
This process entails separation of sea water to two streams. Fresh one with very small concentration of salts dissolved and one with highly concentrated brime. Various forms of energy are required for the success and thereby emergence of different innovations. Different technologies based on different means of achieving this. But not all have a potential future. The MSF, RO and MED have been prophesied to be the dominant means although currently MSF and RO are the widely used.
So what are some of the technologies used? Multiple-stage flash distillation is one of them. This one is based on the principle of flash evaporation. The resource is evaporated by reducing the pressure as opposed to raising temperature. The economies of the MSF heating technology are achieved by regenerative heating where the sea water flashing in each flash chamber or stage gives up some of its heat to its counterpart going through the flashing process.
Multiple effect distillation is the form of distillation process. And is also thermodynamically efficient. The process takes place in a series of evaporators called effects and uses the principle of reducing the ambient pressure in the various effects. The MED plant steam economy is proportional to the number of effects. MED plants can have 3 types of tubes, that is, horizontal, vertical or submerged. Most recent application have been in the Middle East. Although their number is still relatively small compared to MSF plants, their numbers have been increasing.
Another technology used is the vapor compression distillation. Here the heating of marine aqua comes from the compression of vapor. The vcd plant takes advantage of principle of reducing the boiling point temperature by reducing pressure. Two methods are used to condense vapor, a mechanical compressor that helps to produce enough heat to vaporize incoming sea water and a steam jet that works the same. This process is normally used for small scale desalination units.
There is also the method of Reverse Osmosis (RO). Where external pressure, more than the osmotic pressure of the marine water, is applied thereby overcoming the osmotic pressure. Therefore leaving behind dissolved salts with the increase in their concentration. In the recent past various developments have emerged to assist in reducing operating cost of the RO plants.
Methods such as solar evaporation, freezing and potabilization are used but not as often as the ones described above.
Statistically the marine makes up 97% of the global aqua storage. Whereas the locked amount by the glaciers and ice caps amount to 2% of the total supply. The percentage available for human use is about 0.5%. Supplied by lakes and rivers. Water from the sea is neither suitable for consumption by humans nor industrial use. There by desalination being considered as an important alternative for sourcing out fresh water.
This process entails separation of sea water to two streams. Fresh one with very small concentration of salts dissolved and one with highly concentrated brime. Various forms of energy are required for the success and thereby emergence of different innovations. Different technologies based on different means of achieving this. But not all have a potential future. The MSF, RO and MED have been prophesied to be the dominant means although currently MSF and RO are the widely used.
So what are some of the technologies used? Multiple-stage flash distillation is one of them. This one is based on the principle of flash evaporation. The resource is evaporated by reducing the pressure as opposed to raising temperature. The economies of the MSF heating technology are achieved by regenerative heating where the sea water flashing in each flash chamber or stage gives up some of its heat to its counterpart going through the flashing process.
Multiple effect distillation is the form of distillation process. And is also thermodynamically efficient. The process takes place in a series of evaporators called effects and uses the principle of reducing the ambient pressure in the various effects. The MED plant steam economy is proportional to the number of effects. MED plants can have 3 types of tubes, that is, horizontal, vertical or submerged. Most recent application have been in the Middle East. Although their number is still relatively small compared to MSF plants, their numbers have been increasing.
Another technology used is the vapor compression distillation. Here the heating of marine aqua comes from the compression of vapor. The vcd plant takes advantage of principle of reducing the boiling point temperature by reducing pressure. Two methods are used to condense vapor, a mechanical compressor that helps to produce enough heat to vaporize incoming sea water and a steam jet that works the same. This process is normally used for small scale desalination units.
There is also the method of Reverse Osmosis (RO). Where external pressure, more than the osmotic pressure of the marine water, is applied thereby overcoming the osmotic pressure. Therefore leaving behind dissolved salts with the increase in their concentration. In the recent past various developments have emerged to assist in reducing operating cost of the RO plants.
Methods such as solar evaporation, freezing and potabilization are used but not as often as the ones described above.
