Solar desalination plantDuring the last few years several proposals have been designed to increase the options available to obtain fresh water, the reason for this is that the consumption of this natural resource is extremely high, while its production is limited. That Desalination is a process carried out with the objective of eliminating the salt contained in brackish or sea water. All this with the aim of transforming the water into a substance that can be consumed as well as used by humans and animals.
What is a desalination plant?
In order to carry out the deanilization process, it is necessary to use machinery that is designed for it, this is known as a desalination plant, although it is also often called a deanilization plant. Desanilization plants are equipment that capture salt water and process it to transform it into fresh water; they are generally built near the sea.
It is important to mention that previously this type of machine only worked with conventional electrical energy, however, a new proposal has been developed that has allowed the use of solar energy as a resource to operate the desalination plant system; this has caused the economic investment involved in the use of these machines to be greatly reduced, since only the renewable energy of the sun is needed for its use.
Types of desalination plantsDesalination plants are highly complex machines that perform various procedures to achieve their main objective (desalinating water). However, classifying them can be relatively simple, the different forms are:
Industrial Desalination Plant This type of machine is usually used in large cities that lack fresh water or have a shortage of this resource. They are generally built on coasts, so that they can capture salt water quickly and the desalination process is much more efficient.
Regarding the production capacity of desalination plants, it is important to know that this can vary with each model, since depending on the size of the plant, the amount of water it receives and transforms changes. However, the plant with the highest deanilization capacity has transformed 110 liters per second.
Portable deanilization plant It is designed in the same way as an industrial desalination plant, except that it is smaller in size and has a lower salt removal capacity. This type of desalination plant is generally used to supply homes, farms or very small communities, as the production capacity is usually 1,500 liters per day.
According to the type of energy used
Another way to classify desalination machines is according to the type of energy they use. Now, taking this into account, the different models of desalination machines according to their type of energy are:
Solar desalination plant It is the one that uses the energy found in the sun's rays to operate. For this, the plant uses a set of solar panels, which will receive the light energy to transform it into electrical energy that will be used to operate the desalination plant.
Conventional de-sanitizing plant On the other hand, conventional desalination plants are all those that operate with conventional electrical energy, regardless of their size, technology used, among other aspects.
How does a solar desalination plant work?
The operation of such a machine may vary according to the type of technology used, however, this process usually has a series of standard steps that are fulfilled regardless of the technology used by the plant. However, the operation of a desolder consists of the following phases:
- Water collection: This is the first step, in which the machine begins to collect seawater to start the process.
- Pre-treatment: In this phase two filtrations of the water are carried out, in order to remove any type of body or foreign material. Likewise, the water is also conditioned by means of various chemicals.
- Desalination: This is the process of removing the salt from the water to the point where it can be consumed; this may vary according to the technology or method used by the plant.
- Salt return: The brine (salts and other minerals) is then returned to the sea to be dissolved in the non-desalinated water.
- Disinfection and fluoridation: Finally, the desalinated water undergoes a disinfection and fluoridation process so that it can be distributed to humans.
What are the existing desalination methods?
There are different ways to carry out a desalination process, among the most used it is possible to mention the following:
- Distillation: In this process, evaporation and condensation of the water are used to separate it from the salts it contains.
- Freezing: Water is subjected to several refrigeration processes to obtain ice crystals. This process can be carried out with the aid of a refrigerating agent or under vacuum.
- Flash evaporation: Consists of a technological process that performs sudden evaporation and then condenses the water. This process is similar to distillation, only it is much more streamlined.
- Reverse osmosis: A process by which water is pressurized (kept under constant pressure in an enclosed space) to remove unnecessary elements from the water, such as bacteria and minerals.
What is the first solar desalination plant?
Seawater desalination is a project that has been in development for several decades, however, the first solar desalination plant has been created recently; it is a project carried out in Saudi Arabia, which is valued at 130 million dollars.
It will contain a 20MW photovoltaic plant, which will be able to power the desolination plant, whose production capacity will exceed 60,000 cubic meters of water per day. The technology used for desalination will be reverse osmosis. It is worth mentioning that the city that will be supplied by this plant is Al-Khafji.