Emission Control Technology
Spray Dryer Absorbers facilitate the removal of acidic pollutants, heavy metals, and dust from flue- and off-gases at fossil-fuelled power plants, waste incinerators and industrial installations.
The Spray Drying Absorption process – a semi-dry flue gas desulphurization and cleaning process – facilitates a reaction efficiently transforming gaseous pollutants such as e.g. SO2, SO3, HCl, Hg, and dioxins into a slaked lime Ca(OH)2 absorbent to form a stable and dry powdery product that is easy to store and transport.
Every Spray Drying Absorption process is tailored to meet the client’s requirements as well as applicable environmental legislation. The absorbers boast well-proven system features such as e.g. peak-control and activated-carbon injection which have been designed for the purposes of ensuring low mercury and dioxin emission.
The essential process stages are:
Hot, untreated flue gas is introduced into the Spray Dryer Absorber via a flue gas disperser and subsequently comes into contact with a highly reactive absorbent that will be atomized by a Rotary Atomizer.
An efficient contact between flue gas and absorbent allows for rapid mass transfer of acidic components from the flue gas into the alkaline absorbent. The absorbent neutralizes the absorbed acid (SO2 + Ca(OH)2 -> CaSO3/CaSO4 + H2O). While this reaction takes place, the water is evaporated, thus forming a dry powder. A fraction of the dry powder will be deposited at the bottom of the absorber chamber and discharged from here, whereas the main part is carried to the downstream dust collector while the cooled flue gas leaves the chamber. The flue gas – now clean – passes from the dust collector to the stack without re-heating.
The Spray Dryer Absorber – the Rotary Atomizer, the Gas Disperser and the Absorber Chamber – is the heart of the Spray Drying Absorption process.
Spray Drying Absorption - the unique use of the spray drying technology for acid-gas absorption - was originally invented by GEA in the 1970s.
Ever since, it has been subject to continuous further development and optimized to meet changing conditions and requirements. Hence, the process stands as an efficient, versatile and thoroughly tested technology.
GEA Niro®
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F-1000 |
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F-360 |
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F-100 |
F-100 / D |
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Power plants |
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Small boilers |
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Sinter plants |
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Smelter plants |
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Pelletizers |
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Coking plants |
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Worldwide, more than 500 Spray Drying Absorption plants are installed at power stations, steel plants, waste incinerator plants, and at plants burning hazardous waste. They all share one common trait: They are operated in accordance with or above required performance stipulations as laid down by local authorities. Even today, the very first plants, installed in the 1980’s, are still operating satisfactorily and successfully.
Explore how GEA’s SDA systems can be tailor-designed to meet the rigorous demand of diverse industrial environments, offering robust performance, flexibility and comprehensive support to ensure energy efficiency, optimal operation and compliance with environmental standards.
The dry sorption process removes acid gases like sulfur oxides (SOx) and hydrogen chloride (HCl) through two basic steps. The first step is injection of a dry sorbent into the entrained flow reactor. The second one removes the formed compounds through a downstream particulate matter control device such as a baghouse filter, electrostatic precipit...
For the wet desulphurization of flue gas, a scrubbing liquid is recirculating and injected to the exhaust where SOx is absorbed in the liquid and reacts. Simultaneously, the flue gas is saturated with water vapor. The reagent is fed to the sump of the scrubber unit and intermittent dewatering is used to drain the reaction agent.