Energy-saving seawater desalination using sunlight and piping systems

Abstract

Seawater desalination or deionization of water by sunlight and the use of piping systems, characterized in that, in addition to the open pipe with forward-flowing liquid that becomes increasingly salty due to sunlight and evaporation, and the pipe for freshwater, a return piping system for water with a high salt content is present.

Description

[0001] For a very long time, "freshwater" has been obtained from saltwater through sunlight / solar heat and evaporation. In this context, it is important to know that the Earth's usable water resources are limited and becoming increasingly scarce. Depending on the source, 97.5% of all water is saltwater, and of the remaining 2.5%, only 3% is accessible. Water with a salinity below 0.1-0.2% is often referred to as freshwater and requires further treatment to be suitable for drinking. Several methods exist for seawater desalination, but only a few produce the vast majority of freshwater (evaporation, pressure, etc.). Pressure and heat account for 25-50% of the costs. Given that over two billion people worldwide lack access to drinking water, new, energy-efficient, affordable, and simple solutions are urgently needed.

[0002] Since there are many different methods for seawater desalination, only a few further examples are listed here: In electrodialysis, ions are electrochemically separated from uncharged particles in ion exchange membranes using an applied electrical voltage. Stacks of electrically alternating membranes consist of many pairs. This results in an accumulation of salts in one area of ​​the stack and a reduction in salt concentration in another. The energy required for electrodialysis separations is proportional to the salt concentration. For this reason, electroosmosis is more efficient at low salt concentrations than, for example, reverse osmosis, in which the salt solution is forced through a semipermeable membrane under high pressure.

[0003] Capacitive deionization requires only porous carbon electrodes and electricity. It is based on a reversible electrochemical principle. The ions are absorbed into the electrode material. Ideally, for every electron at the anode and every positive charge at the cathode, one cation and one anion are absorbed. Research is also being conducted on new carbon nanomaterials such as graphene or so-called "carbon nanoonions" regarding the storage of these ions as energy storage media.

[0004] Other interesting approaches to seawater desalination / deionization include desalination using a gel (Institute for Technical Chemistry and Polymer Chemistry at the Karlsruhe Institute of Technology (KIT), "hydrogel"). Crucial to this process are electrically charged molecular groups that retain dissolved salts as they penetrate the gel. When the swollen absorber is squeezed, the emerging water has a much lower salt concentration than before. Another idea is to use less energy by removing salt compared to producing water (Adionics SAS: AquaOmnes).

[0005] The general problem of seawater desalination / deionization of water is to produce fresh water cheaply, energy-efficiently and in large quantities.

[0006] Many solutions exist for seawater desalination (deionization), e.g.: DE000002650482A1, Evaporation by solar heat, DE202007012405U1, Distillation, Electric or solar energy, CN000211445106U, with evaporation, CN000208667184U, furthermore with membranes, CN000206278964U, by reverse osmosis, CN000112062233A, only partial recirculation of salt water, DE202021102883U1, using piping systems through electricity and / or magnetic fields, DE000004334317A1, electrochemical membrane process, WO001998022203A1, series-connected electrodialysis.

[0007] My invention is based on the further development of seawater desalination through evaporation and special piping systems, in order to obtain fresh water in an energy-saving, inexpensive and simple way.

[0008] The existing solutions fulfill their function under the circumstances, but do not have the capabilities of the aforementioned invention.

[0009] The possibility of an effective seawater desalination plant or deionization of water is desired, and the invention specified in claim 1 for the rapid production of a plant using evaporation by solar heat and the use of piping systems fulfills these requirements.

[0010] One example: The actual desalination process (according to claim 2) takes place through evaporation. In contrast to other methods, there is no central desalination plant; instead, the pipeline itself obtains the fresh water. Examples are in Fig. 1 and Fig. Figure 2 shows a cross-section. Thus, a further advantage of the above invention is that no significantly large factory site is required.

[0011] As described in claim 3, the consistent recirculation of highly ionized water 3 in a pipeline saves resources. This results, among other things, in a reduced energy and saltwater requirement. Ideally, the desalinating pipelines run as straight as possible towards the target area (apart from measures taken to account for thermal expansion).

[0012] There is a pipeline for returning the highly saline saltwater. A parallel pipe, or another section of the pipe system containing freshwater, has a reversed flow direction according to claim 4. The pumps are not shown. As described in claim 5, the upper portion of the pipe system containing, for example, seawater 1, consists of a wide, open pipe and transparent condensation slopes. The condensed freshwater 4 is directed to the freshwater pipe.

[0013] According to claim 6, the pipe system can also be partially installed in the ground, so that only the upper portion is visible for evaporation. As described in claim 7, cleaning robots can drive over the transparent separating disc / surface. In the event of obstacles such as roads, the cleaning robot's direction of travel is changed, or the entire pipe system is routed within a larger pipe with space for the cleaning machine, either above or below the obstacle. According to claim 8, evaporation can optionally be enhanced by a vacuum.

[0014] If, after a longer distance, the salinity of the seawater becomes too high, it is returned in a pipe – as described in claim 9 – (measured by sensors or based on empirical data). From that point on, the second pipe, if present, can also be used to transport fresh water or become superfluous.

[0015] According to claim 10, in the case of differences in height, the liquids in one direction can also be used as a drive and / or to support the pumping of the liquid in the other direction.

[0016] Both round, oval and square tubes and combinations thereof are conceivable - as shown in claim 11.

[0017] This special pipeline system will gradually evaporate the seawater over long distances, producing fresh water.

[0018] Depending on the manufacturing process, cleaning robots can be installed in square, round, or oval pipes (according to claim 12) to clean the pipeline as needed. If this type of pipeline cleaning proves disadvantageous in certain situations, a mechanism for opening the pipes is useful, as described in claim 13.

[0019] The pipelines can (according to claim 14) consist of plastic, metal, other materials or combinations thereof.

[0020] The deionization takes place - as described in claim 15 - at normal ambient temperatures and low pressure (apart from the pressure conditions generated by the pumps).

[0021] Since the aforementioned invention itself does not use membranes, the problem of contamination and the necessary cleaning is less pronounced than with other seawater desalination processes. Of course, according to claim 16, screens, filters, and methods for disinfection and algae removal (ozone, UV light, etc.) are necessary, ideally installed before the actual deionization process. This is particularly important if the freshwater is intended for drinking water use and not just for land and agriculture.

[0022] A major advantage, as with other deionization methods, is that primarily, apart from pump components, there are no moving parts that require regular maintenance or can fail.

[0023] The pumps and deionization devices can – as described in claim 17 – obtain the necessary or supplementary power, for example, from a photovoltaic system / solar cells next to the pipeline or from wind turbines. Even if this reduces evaporation, transparent solar films could optionally be installed on the pipeline system according to claim 18.

[0024] The inlet and outlet at the beginning of the seawater desalination plant can – as described in claim 19 – consist of two large pipelines whose outlets must be sufficiently far apart to prevent the inlet from mixing with the higher salt concentration of the outlet. This is easily achievable, for example, if the pipeline outlets are also at different elevations. Furthermore, it is important to ensure that the higher salt concentration of the outlet does not cause environmental damage to the underwater environment. Reference symbol list 1 open pipeline containing salt water / seawater / ionized water 2 Pipelines with fresh water 3. Return pipeline with high salt content 4 condensed freshwater QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 000002650482A1

[0006] DE 202007012405U1

[0006] CN 000211445106U

[0006] CN 000208667184U

[0006] CN 000206278964U

[0006] CN 000112062233A

[0006] DE 202021102883U1

[0006] DE 000004334317A1

[0006] WO 001998022203A1

[0006]

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