As we address the global environmental issue of clean air, there is a concerted effort underway to restrict the emission of sulfur dioxide into the atmosphere. This has necessitated the construction of flue gas desulfurization (FGD) systems at coal-fired power plants. The operating environments within these systems are very corrosive. Because of these complex conditions, a wide array of highly corrosion-resistant stainless steels and nickel alloys are used in their construction.
Where stainless steels are used for absorber towers, resistance to chlorines is essential. Sandmeyer Steel’s stainless steels found in these units include 316L/316, 317L/317, 317LMN, superaustenitics 904L and SSC-6MO, duplex LDX-2101®, 2205, and 2507.
In components experiencing the most severe conditions within an FGD system, resistance to chlorides and sulfuric acid is essential. They include absorber inlet ducts, outlet ducts, chimney flues, and dampers. High nickel alloys are usually required in these service conditions. Sandmeyer Steel’s 625, 825, and C-276 are often used.
The technology for capturing and storing carbon dioxide from the gas emissions of fossil-fired power plants is still being developed. Carbon dioxide capture and storage is the process of extracting CO2 from a combustion process and storing it in geological formations for extended periods of time.
Large stationary sources of CO2 are the primary candidates for this clean air technology because the systems themselves are extremely large and complex. In addition to power plants, other likely applications include other energy-intensive industries such as cement, iron and steel production, and natural gas power systems.