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At what temperature is sodium bicarbonate effective ? |
Thanks to the properties of sodium bicarbonate, the NEUTREC® process retains its efficiency across a wide range of flue gas temperatures (from 140°C to over 300°C), thereby obviating the need for precise temperature control.
A minimum temperature of 140°C is recommended to permit rapid thermal activation of the bicarbonate into sodium carbonate.
A lower temperature is possible where certain precautions are taken:
- Injection of the sodium bicarbonate at a higher temperature (above 160°C) and low temperature filtering (situation often encountered in secondary metals smelting)
- Long contact time between the injection point and the filtration stage.
To prevent acid condensation in the filter, it is good practice to select a filtration temperature around 20°C higher than the acid dew temperature (typically 120 to 140°C in MW incineration).
The maximum operating temperature is limited by:
- the removal of heavy metals and polychlorophenyls, dioxins and furans: 200-210°C;
- withstanding power of the filtration media: 220-250°C as a function of the media
The NEUTREC© process can function at higher temperatures (above 600°C) when used solely to remove acids (HCl, SO2, HF, etc) (as in glassmaking).
SOLVAY’s technical teams can help you find the best solution for your particular application.
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