Seawater FGD (Flue Gas Desulphurization)
ANDRITZ offers seawater flue gas desulphurization with low operating and maintenance cost for coastal regions.
Based on extensive experience with limestone FGD since 1995, we developed a seawater flue gas desulphurization process for use in power plants in coastal areas by taking full advantage of the cooling water circuit downstream of the condenser.
Ideal system for coastal plants
The special ANDRITZ seawater FGD technology was developed based on a cooperation between former AE&E locations in Graz and Shanghai. It can operate without additional absorbent and does not create any by-products or waste requiring further treatment or disposal. Raw flue gas is introduced into the seawater being sprayed in a spray tower and SO2/SO3 absorption is achieved at the same level as in the limestone process. By using well-proven open spray towers and no rotating components, the system achieves easier maintenance and lower pressure loss. Depending on the actual boiler load and SO2 concentration, ANDRITZ’ seawater FGD process is flexible and able to operate with different numbers of spray banks in order to optimize energy consumption. Research activities on packing absorber technology are in progress to keep our portfolio at the highest level.
The principle of our process is to make use of the natural alkalinity of seawater instead of a limestone solution to absorb the acidic substances in flue gas, such as SO2. At first the SO2 is converted into HSO3- in our spray tower. Then the HSO3- is oxidated to SO42- in our CFD-optimized aeration basin in order to raise the DO and reduce the COD value. Meanwhile, the CO2 formed by the neutralization reaction is stripped by aeration membrane and the pH value is raised as a result, thus meeting the legal requirements.
ANDRITZ is able to provide customized seawater FGD design and planning, subject to the general arrangement of the power plant.
- Outstanding for various fuels (lignite, hard coal, oil, and biomass)
- SO2 removal up to 99% or even more
- Environmentally friendly, no by-products
- Seawater as a free absorbent
- Open spray tower, no plugging or scaling, low pressure loss
- Low operating and maintenance costs
- High availability
- Options for construction materials (high-alloy carbon steel with rubber lining, concrete with PP-lining, glass fiber reinforced plastics)