Prevent contamination, corrosion and precipitation
Organic contamination of pure water in the production of electricity can cause several problems with high costs. No one will deny that. An example of this is organic contamination of ion exchangers. This leads to a higher frequency of regeneration or replacement of the resins. When organic substances break down, organic acids are formed, which lower the pH. This can eventually lead to corrosion in the turbine. And you want to avoid that at all costs. The heat exchangers are not spared either. Organic precipitation (often together with inorganic products) reduces the efficiency.
The cause of organic contamination
The raw material for steam production to generate electricity is water. This is often surface water or groundwater. It is as clear as day that both water sources are not free of organic matter. The raw water must therefore be treated before it can be used in the production process. The water treatment installation sometimes has a hard time.
Surface water has large seasonal fluctuations in organic load. In recent years, groundwater scarcity has been a problem, requiring a switch from groundwater to surface water or other sources. Even purified wastewater is used sometimes. The efficiency of the water treatment systems is then really put to the test. A similar phenomenon occurs in combined heat and power plants where condensate from (mainly chemical) process installations is used, which may also be contaminated.
Measure the organic contamination
To measure is to know. The prevention of organic contamination starts with its detection. The concentration of organic substances in water is referred to as TOC, (Total Organic Carbon). TOC analysers come in different shapes and sizes. The most elegant way, used in Mettler Toledo Thornton analysers, is by using oxidation through high-intensity UV light that completely converts the organic substances in a continuous water flow into carbon dioxide (CO2). The conductivity of the water is measured before and after the UV lamp; carbon dioxide in water, as we know, increases the conductivity. The difference between the two conductivity measurements correlates with the TOC.
A robust and durable analyser
What operators and technicians do not want are additional problems and time-consuming maintenance. That's why a TOC analyser with UV oxidation and conductivity measurement before and after is such a good choice. There are no covers or valves, no moving parts, no membranes and no reagents, which means periodic maintenance is kept to a minimum. These analysers have an additional advantage in terms of process control and quality assurance. They measure continuously and not in batches. So there is never, ever, a part or period in which the water is not analysed.
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