Although being readily available, seawater has limited agricultural or industrial use. One way of making use of seawater is applying reverse osmosis. This method is widely known but has some considerable drawbacks.
Reverse osmosis consumes large amounts of electrical energy and has high maintenance. In addition it needs a constant renewal of membranes. For these reasons and for the fact that brine is returned into the oceans, we can say that this method has a significant impact on the environment.
Thermal desalination processes are not new but have now been completely redesigned with great advantages. Thermal desalination can now be carbon neutral, versatile and further more, easily implemented.
The IKERA RD8 technology has very low operating costs due to the absence of membranes and the use of thermal energy, that can be satisfied 100% by renewable energy.
In conclusion, as a business model, thermal desalination has lower running costs and two sources of income: desalinated water and the extracted salts.
Thermal energy is the main source of energy used. This can come from renewable energies such as CSP, MINI-CSP, FVT, geothermal, biomass, waste heat or a combination of the above mentioned. Also energy from non-renewable sources can be used, solely, or a combination with renewable sources. For arid areas, CSP is recommended.
While CSP temperatures can reach 420º C, we work with heat exchangers that provide us with a temperature range between 40º C and 80º C and thanks to the excess energy we can work during the night time.
Seawater or aquifer continuously accesses a homogenisation tank that feeds the IKERA RD8 physical reactor, in which only H2O is evaporated, to later be condensed and mineralised according to the required use.
The technology does not require membranes and the use of electricity is minimal.
The solid part, salts and minerals with adjustable humidity as low as 0.2%, is transferred to dry deposits according to the subsequent use required: wholesale, mineral extraction, crystallisation of different salts, lithium extraction, etc.
In reverse osmosis plants which have already been installed, IKERA RD8 technology can take care of the brine, revaluing the salts and minerals from the sea as well as totally recovering the water. Said brine has a proportion of water/salts and minerals of 30%/70% or less, so the costs of revaluation of salts and minerals may be feasible with appropriate parallel technologies, especially lithium extraction.
IKERA RD8 plants can be easily implemented and the necessary thermal energy is readily available. Therefore, having a larger number of smaller plants distributed globally is possible, avoiding water transport between regions.
There is also the option of working with water with a high saline concentration from the subsoil inland.
We have conducted viability studies on Mediterranean seawater and brines with salinity ranging from 0.3% to 80%, all of them being feasible.
We are looking for industrial partners or venture capital for small-scale industrial scaling, preferably in the Middle East or arid zones for implementation with thermal energy from renewable sources.
The design of the plants is currently not prepared to compete on a large scale, so industrial scaling should take three scaling prior to reaching large-scale scaling.
Readings of interest
Reassessing the projections of the World Water Development Report