For manufacturing of ceramic products polysaccharide-based additives are used. These additives will be concentrated in the process water cycle. After a short operating period already this phenomenon leads to a blocking of reverse osmosis membranes used for deionisation of process water. Thus increase costs for replacement of defective reverse osmosis membranes considerably.
To advance the life time of reverse osmosis membranes a two-staged process has been applied. In the first process stage the additive is catalytic oxidized with hydrogen peroxide in a DTE composite catalyst cartridge. Subsequently the deionisation of treated process water in a reverse osmosis plant takes place in a second stage.
The goal was by oxidative chain cleavage to convert the polysaccharide-based additive into oligomer respectively monomer sugar derivatives, which do not disturb the reverse osmosis process.
Whereas acid hydrolysis has been favoured so far, now a chemical treatment of aqueous model solutions or real process water in the presence of H2O2 at 60°C with a reactor containing DTE composite catalyst stack is used.
The analytical estimation and identification of the additive was prepared by gas chromatography-mass spectrometry coupling (GC-MS). In order to exclude errors in manufacturing process the chemical and physical phenomena which lead to a blocking of the reverse osmosis membranes were simulated.
Advantages of composite catalyst elements for this application are:
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Increase of membrane life time by factor 7 to 10.
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A neutralisation step is not required.
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The organic components are not only catalytic cleaved but also degraded stepwise to mineralising products.
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The process water is added hydrogen peroxide simply.
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The catalytic active layers are exchangeable immediately, if their catalytic activity is not existent anymore.
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The flow initiators are reusable.
