Composites are the material of choice for pollution control systems and components, which typically operate in a highly corrosive environment. Fiber reinforced plastics (FRP) provide high corrosion resistance, a high strength-to-weight ratio and cost advantages versus stainless steel and high nickel alloys also used in these applications.
A range of industries use FRP materials in systems that remove toxic gases and particulates from exhaust smoke and treat contaminated water and chemicals. Limestone slurries and chemical solutions used to reduce air pollution are abrasive and cause corrosion in metal components, making composites a perfect solution. Pollution control technology requires corrosion-resistant “scrubber” tanks and vessels (some over 100 feet in diameter), stacks, chimney liners, packing support systems, ductwork and piping.
Coal-fired power plants, a key target of the Clean Air Act, are required to install flue gas desulfurization (FGD) technology, which is highly efficient at removing sulfur dioxide (SO2). When coal is burned, the sulfur in it combines with oxygen to form SO2, which must be cleaned or scrubbed before leaving the smokestack. Wet FGD, the most common process, uses an aqueous mixture of lime or limestone to spray the flue gas prior to discharge.
Most of the coal-fired power plants in the U.S. are 30 to 40 years old and have been upgraded to meet emissions regulations, according to the American Society of Mechanical Engineers (ASME), which reports that some 1,400 coal-fired power plants are operating in the U.S. Since 2004, roughly 130 scrubbers have been installed at coal-fired power plants in the U.S., with the average installation requiring about two years to complete, relates the ASME.