Decarbonization plants
Decarbonization using ion exchange causes partial desalination of water by removing the so-called temporary hardness. This is the share in the earth alkali ions calcium and magnesium that are equally present in the hydrogen carbonations. Calcium and magnesium ions are exchanged via a slightly acidic cation excahnger in the H-form for H+ ions. The H+ ions that are released bond with hydrogen carbonations to form carbonic acid. In the process, only the equivalents of existing hydrogen carbonate concentrations can be exchanged.
Matrix(-COOH)2 + Ca2+ + 2 HCO3- = Matrix(-COO)2Ca + CO2 + H2O
The result is a soft water quality with a total hardness that corresponds to the original difference between the total and carbonate hardness. The carbonic acid that is simultaneously released can be removed out as carbon dioxide gas.
When the ion exchange capacity is exhausted, the filter is regenerated with diluted hydrochloric acid. No excessive quantities are required – only an equivalent of the separated number of cations.
Matrix(-COO)2Ca + 2 H+ = Matrix(-COOH)2 + Ca2+
The waste water that is thus generated is also only mildly acidic. For highly economic operations, it is recommended that you use an acid measurement device that is optionally available. For variations in the water qualities, we recommend the use of a quality-based controlling system using our process titrators. Here, regeneration is triggered exactly based on a certain charged status. Regeneration is done under counter-current. The resin quality and design of the plant facilitate regeneration with least quantities of rinsing water. In case of normal well or city water qualities, this is less than one percent of the generated pure water quantity.
Decarbonization is not affected by increased quantities of iron and manganese in the raw water. Iron and manganese are also separated. Factories that have their own well water supply can often do away with a preliminary de-ironization plant for generating industrial water. The entire control of the operating and regeneration processes is taken over by a micro-process controller that can be programmed via a panel; the operations data can be permanently saved in EEPROM; However, there are other control variants, for e.g. via SPS. Operations and regeneration phases are switched in automatic operations through individual well-arranged pneumatically controlled membrane valves.
Areas of application
Feed water preparation for re-cooling plants and air washers
The decisive cost factor for operating re-cooling plants and air washers is the consumption (and wastage) of water and waste water. Decarbonized water allows you to operate the plant with a much higher thickening factor. Using a cutting device, the feed water can be set to an optimum between sedimentation tendency and corrosiveness. Apart from the waste water minimization according to § 7a, Water Act, a decarbonization plant is often amortized in less that a year. The total salt content in the circulation water restricts the thickening of water.
Preparation of feed water for steam generators
Even in case of boilers, the thickening ratio to be achieved is a decisive cost factor. The waste salt water quantity should not exceed 5 to 10 percent of the steam quantity. Decarbonized water not only allows operations at much higher thickening ratios, it also avoid the risk of corrosion due to hydrochloric acid in the condensate system. Silicic acid and salt content restrain the thickening.
Autoclave circuits
Decarbonised water can be set in such a manner that you can achieve sedimentation-free operations in all autoclave types.
Decarbonization as part of complete desalination
Decarbonization is the most cost-effective desalination process – using an equal quantity of hydrochloric acid, you can remove almost equal quantities of cations and ions from the raw water. Hence, decarbonization is often recommended as the first process step in the desalination system.
Process and rinsing water
For use in process baths and rinsing water – for e.g.in the surface treatment of metals (degreasing and phosphating systems, chromium plating systems, eloxal systems, galvanic baths, pre-treatments in case of coatings) – decarbonized water often meets the quality requirements.
Beverages industry
Decarbonized water meets the quality demands for manufacturing beer and fruit juice beverages.
