How to store and produce energy using salt
In recent years, energy storage using salt has become more common. A method particularly favourable for green energies that can only produce energy under specific weather conditions. We at Lyma Kemiteknik have been involved in several of these projects and know which applicators are needed to handle the medium.
For decades, research has looked at whether it is possible to store energy already produced in order to use it when needed. This has been particularly desirable for green energies such as solar, wind and wave energy, which we know only produce energy when the sun shines and the wind blows.
Salt is melted via solar towers
For many years, there have been 'solar tower' projects in areas of the world with high sunshine hours. These facilities typically use mirrors over a large area that reflect and collect solar rays to a focal point, usually at the top of a tall tower, where a tank filled with common salt stands. The concentration of all the sun rays from the mirrors on the ground hitting the 'tank' will cause the temperature to rise and the salt in the tank will melt and become liquid. The temperature of the liquid 'molten salt' is usually between 400 and 600 degrees centigrade.
The liquid salt is then circulated from the tower to the ground, usually to a tank, and then pumped through heat exchangers where it heats water into steam, which is then used to produce electricity in a steam turbine and sent out onto the grid. The steam is condensed and pumped back to the circuit.
Pumped in a perpetual cycle
The cooled molten salt, which was used to produce steam, is pumped to the collection tank, from where it is pumped up the solar tower and the process can start again. At night, or when the sun is not shining, the process can continue as the molten salt is stored in insulated tanks and can be used to produce steam for the turbine.
If the plant is not energised by the sun, wind, waves or other forms of energy, the molten salt will slowly cool and return to its original form - salt crystals. When the plant is energised again, the salt melts and is used to create steam for the turbine, and electricity is generated. The efficiency of these plants is usually between 70 and 80 %.
The method is used for several forms of energy
The same process can also be used for other forms of green energy. When the wind is good, or at night when energy consumption is generally low, the excess capacity from wind turbines, for example, can be used to heat (melt) salt which is stored in well-insulated tanks and kept there until energy consumption increases again or the wind dies down.
The molten salt can then be pumped to heat exchangers to produce steam for the turbine and electricity production can continue, even if there is little or no wind. This method requires relatively durable and robust pumps, valves, pipes, etc. As salt is quite corrosive and abrasive, the process equipment must also withstand high temperatures.
Lyma has knowledge of the process
We at Lyma Kemiteknik have been involved in several of these projects in recent years, where we have been able to utilise our good knowledge and experience in pumping and handling corrosive and abrasive media. In these applications, pumps with magnetic drive or split-tube pumps are often used, often with nitrogen or other inert gas as a thermal barrier, which ensures safe and leak-free operation without the risk of crystallisation.
In addition to pumps, you will find a wide range of tanks, pipes, valves and gaskets in our product range. As the only distributor in Scandinavia, we can supply everything you need to perform an efficient and safe flow.