Title of Invention

A PROCESS FOR DESALINATION OF SEA OR BRACKISH WATER

Abstract

A process for desalination of sea or brackish water The present invention relates to a process for desalination of sea or brackish water, comprising mixing ammonia (NH3) into said water to form an effective amount of ammonium hydroxide (NH4 OH) to react with NaCl salt molecules present in said water and weakened said NaCl bond in said molecules; spraying said water as a fme spray near the top of an enclosed process chamber; exposing the sprayed water to an effective amount of CO2 combustion exhaust gas to react with said weakened sah molecules and form and remove sodium carbonate (Na2CO3) and ammonium chloride (NH4Cl) solids in a clarifier below said process chamber, settling and removing solids in a clarifier below said process chamber; removing said solids through an underflow outlet pipe and discharging desalinated water as an overflow from said clarifier.

Full Text

The present invention relates to a process for desalination of sea or brackish water. Water for communities, agriculture and industry is more and more needed, and not available in many areas of the world. Sea water cannot be used because it contains salt, and existing methods for removing salt are slow, difficult and costly, and require much energy. Energy consumption is increasing world wide and most of it is produced by combustion of oil, gas, coal, wood and other organic material, which are polluting the environment. Environmental scientist from all over the world, are now recommending that carbon dioxide (CO2) now being produced and discharged to the sky be reduced, to protect the environment from the bad greenhouse effect CO2 gases have. Many nations have therefore now committed themselves to reduce their CO2 emission, as a legal requirement. The present invention is therefore of great importance indeed, providing a practical process, at low cost, for producing large quantities of desalted seawater, using CO2 for the process from combustion exhaust, which other wise would be contaminating the environment. No existing economical process provides simultaneously these results, although other processes are using similar chemicals. Particularly the ammonia-soda ash process, which Ernest Solvay improved in 1865, by saturating concentrated solution of sodium chloride with ammonia and passing carbon dioxide through it to obtain soda ash. The above and other objects and advantages are obtained in accordance with the present invention comprising a chemical process for desalination of seawater, and removal of CO2 from exhaust. Salt molecules (NaCl) have a strong intemal bond between the Na- and the CI- atoms, which will be broken in two steps. In the first step of the present invention a catalyst being ammonia (NH3) will be carefully metered and mixed with the seawater which has about 3% weight of salt to be removed. The ammonia mixes readily with water and forms (NH4OH), which contains very aggressive reactant molecules. They have strong attraction and are pulling on the CI- atom of the salt molecules in the seawater. This reduces the internal bond, and makes the salt more vulnerable. The second step of said process is performed in an enclosed process chamber, located above a clarifier. Combustion exhaust gas, rich in (CO2) and normally discharged to the sky, harming the environment, is being used for the process. The gas enters through inlet on one side and remains in the chamber for processing. The remaining gas leaves at outlet on the other side. The seawater mixture is pumped into the process chamber to numerous outlets near the top and disperse as non-clogging mist. The CO2 gas molecules are attracted to the Na atom of the salt and further weaken and break the salt molecules apart in the mist of seawater. Two heavy solids are formed, they settle in the clarifier and are removed in under flow outlet. The desalted seawater over flows from the clarifier in large quantities per ton of salt, since salt is only present in about three percent in seawater. The desalted sea water can then be used for communities, industries and agriculture. It still contains some dissolved ammonia and plankton and other microorganisms, which in the ocean are nutrients for other sea life. These nutrients can also be used to fertilize soil for farming. Alternatively, where needed, they can be removed from the water by intense aeration and biological process or by non-clogging filters. The colloidal material flocculates and is recovered as sludge or filter cake. The two solids from the breakup of the salt, and removal of the CO2 gas, are: Sodium carbonate Na2CO3 with specific gravity 2.53, and ammonium chloride NH4CI with specific gravity 1.53. The two solids can be separated by hydro cyclone separator, air conveyor and spray or by other means. There are growing markets and good prices for sodium carbonate. It may pay for the total process and more, rendering the desalted seawater free of charge. The Ammonium in the NH4CI can be recycled by thermal treatment with calcium oxide, or be converted to NH3 and HCl. The chemical formula (or equation) for the reaction for the salt break up with seawater as carrier and 3 weight percent salt and 1 ton of salt being removed is: The abbreviation T meaning: ton in weight. The numbers of the last line represent the molecular weights of the compounds of the equation. The method according to the invention may be carried out with a process chamber including a top plate and a cylindrical wall, above a clarifier with a cylindrical wall connected to a conical bottom with a sump pit. The entrance pipe with numerous dispersing spray outlets is supplying seawater mixed with ammonia. The entrance duct is supplying combustion exhaust with CO2 gas to the process chamber. The exit duct is removing remnant exhaust gas. The over flow weir and the over flow pipe are discharging seawater with salt removed. The splash boards and the ring over flow cover are catching and splashing the water for additional salt removal. The pipe conveyor is removing the under flow from the pit by air injection, which mixes and lightens the material from the pit and sprays it out into the separator. The air is removed at the top of the separator. Certain preferred and illustrative embodiments of the invention are shown on the drawings. On FIG. 1 is a vertical section I showing the process chamber with a clarifier below. On FIG. 2 is a horizontal section II of the process chamber. FIG. 1 and FIG. 2 comprise a process chamber 1, having a top plate 2 and a cylindrical wall 3, above a clarifier 4 with a cylindrical wall 5 connected to a conic bottom 6 with a sump pit 7. The entrance pipe 8 with numerous dispersing spray outlets 9 is supplying seawater mixed with ammonia 10. The entrance duct 11 is supplying combustion exhaust with CO2 gas 12 to the process chamber. The exit duct 13 is removing remnant exhaust gas 14. The over flow weir 15 and the over flow pipe 16 are discharging Sea water 17 with salt removed. The splash boards 18 and the ring over flow cover 19 are catching and splashing the water for additional salt removal. The pipe conveyor 20 is removing under flow from the pit by air injection 21, which mixes and lightens the material from the pit and sprays it out into the separator 22 to separate the materials with different specific gravity. The air 23 is removed at the top of the separator. An improved processing method or plant, in accordance with the present invention, with molecular breakdown and beneficial reduction of salt in-situ in seawater or other salt water, is achieved in a continuous chemical process performed in one or more enclosed process chambers, each located above a clarifier, and arranged in tandem or parallel. Exhaust rich in CO2 gas normally discharged when combusting gas, oil and coal power plant, furnaces and other combustion apparatuses, and is harmful to the environment when reaching the upper atmosphere. The exhaust is being diverted to the process chambers and the CO2 gas used for the process as it is being removed from the exhaust. The seawater has ammonia as a catalyst added and mixed in, in balanced quantities with the salt, to weaken the inner bond of the salt, before the seawater is pumped into the process chamber and dispersed as a fine spray at numerous points near the top. And the fine spray hits one or more splash boards, as the CO2 gas acts there as a strong reactant, connect to the weakened salt molecules and tear them apart. Two heavy solids form with atoms from the salt, ammonia, CO2 and water, and are removed. Namely the compounds of sodium carbonate and ammonium chloride. In the clarifier below the seawater with sah removed is discharged as overflow from the clarifier and heavy solids settle and are removed as underflow and can then be recovered. The number of process chambers can be used in different ways. If two, three or more process chambers are arranged parallel, there is a proportional reduction per square meter of the chamber area, in flow of seawater, salt, ammonia and CO2, and increased desalination of the seawater. As another example, if there are three similar process chambers arranged in tandem, and the combustion exhaust flows from one to the second to the third and remimant exhaust is then discharged there, the seawater mixed with ammonia may be pumped into the second chamber and is processed there. But if the processed seawater still has too much salt, it may be checked for sufficient ammonia and pumped into the first process chamber for a polishing process to meet the desalination requirements. A small portion of mixed seawater pumped, can be diverted and sprayed into the third process chamber for a polishing process to remove remaining CO2 gas when required. The process of the invention is mainly for seawater that has a relative uniform salt content. Seawater has about three weight percent salt, but the percentage will vary in accordance to location. In Fjords and narrow bays, that are receiving large volumes of fresh water the percentage of salt will be less. In tropical zones and shallow water the salt content is higher, but generally does not exceed 4% by weight. Magnesium, calcium and potassium exist in very small proportion in seawater compared with the sodium saU. These metals are needed for most living cells, and a portion of them may be removed in the described process. The seawater also contains plankton and other micro organisms, which in the ocean act as important nutrient for other sea life. These micro organisms can also act as fertilizer when desalinated seawater is used for agriculture in arid or semiarid locale, where increasing population and draught make desalinated seawater an extremely valuable resource as in California, Hong Kong and The Middle East. In the Arabic States much gas from oil wells is flared, and CO2 gas from combustion can be captured and removed in my process to avoid pollution of the atmosphere. The gas can be used as fuel for electric power. The exhaust from these can be diverted and the harmful CO2 gas can be removed and used in the invented process for desalination of seawater in large quantities, which then can be available to make the desert productive for agriculture. Ammonia is now produced in large quantities at low cost, so recycling may not be needed or cost effective. It shall be understood that salt water other than Sea water can be used as an alternate in this invention, and a maximum concentration of 22 percent of sah is being used, to avoid clogging and provide a more reliable process. This invention has been disclosed with respect to certain preferred Embodiments, and it will be understood that various modifications and variations thereof, obvious to those skilled in the art, to be included within the scope of the appended claims. WE CLAIM: 1. A process for desalination of sea or brackish water, comprising mixing ammonia (NH3) into said water to form an effective amount of ammonium hydroxide (NH4 OH) to react with NaCl salt molecules present in said water and weakened said NaCl bond in said molecules; spraying said water as a fme spray near the top of an enclosed process chamber; exposing the sprayed water to an effective amount of CO2 combustion exhaust gas to react with said weakened salt molecules and form and remove sodium carbonate (Na2CO3) and ammonium chloride (NH4CI) solids in a clarifier below said process chamber, settling and removing solids in a clarifier below said process chamber; removing said solids through an underflow outlet pipe and discharging desalinated water as an overflow from said clarifier, 2. The process as claimed in claim 1, wherein said process chamber is provided with splash boards to catch and splash said water for addition salt removal. 3. The process as claimed in claim 1, wherein said water has a maximum salt concentration of 22 percent to avoid clogging during the process. 4. The process as claimed in claim 1, wherein said process is performed in two or more chambers arranged in tandem or parallel for maximum salt removal. 5. A method for desalination of saltwater and/or for removing CO2 from combustion exhaust by the process claimed in claims 1 to 4.

Documents:

442-chenp-2003-abstract.pdf

442-chenp-2003-claims duplicate.pdf

442-chenp-2003-claims original.pdf

442-chenp-2003-correspondnece-others.pdf

442-chenp-2003-correspondnece-po.pdf

442-chenp-2003-description(complete) duplicate.pdf

442-chenp-2003-description(complete) original.pdf

442-chenp-2003-drawings.pdf

442-chenp-2003-form 1.pdf

442-chenp-2003-form 19.pdf

442-chenp-2003-form 26.pdf

442-chenp-2003-form 3.pdf

442-chenp-2003-form 5.pdf

442-chenp-2003-pct.pdf