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Selected Application Recommendations Flue Gas Desulfurization Corrosion resistant composites are extensively used for major components of FGD systems associated with coal based power generation, and many of the structures are the largest in the world. Components include chimney liners, absorbers, reaction vessels, and piping. Operating conditions of flue gas desulfurization processes are quite corrosive to metals due to the presence of sulfur dioxide and sulfur trioxide. These serve to form sulfuric acid either within the scrubbing system itself or from condensation of SO3 as a consequence of its affinity for water and elevation of dew point. Corrosion of steel is further aggravated by the presence of free oxygen which originates from excess air used in coal combustion, or in some processes as a result of air blown into the system in order to oxidize sulfite ions to sulfate. Since there is net evaporation within the absorber, and since coal ash contains soluble salts, chloride levels can be quite high, which in turn limits the use of stainless steel or else requires high nickel content alloys, which are not only expensive, but also require close attention to welding and other installation procedures. The acid and chloride resistance of FRP makes it an excellent choice. Wet scrubbers typically operate near to saturation temperatures of about 140° F, but flue gas may sometimes be reheated to >200° F to increase chimney draft or to reduce mist or plume visibility. The worst upset conditions involve a total sustained loss of scrubbing liquor or make-up water, which may allow temperature to approach that of flue gas leaving the boiler air preheater or economizer, typically up to 350° F. Although such temperature excursions are difficult to generalize, the usual practice is to employ vinyl esters or other resins with good heat distortion or thermal cycling properties. Although there are negligible (if any) combustibles present in FGD systems, the selected resins often display flame retardant properties in the event of accidental ignition or high natural drafts. Gasoline, Gasohol and Underground Storage Tanks Ethanol and EthanoU Gasoline Blends Ethanol derived from corn has increasingly been used to increase the extent of gasoline production and maintain octane requirements. Ethanol can be corrosive to steel, aluminum, and a variety of polymeric materials, due to the alcohol itself and the possible companion presence of water. Ethanol is miscible with water and azeotropic distillation and drying techniques are necessary in fuel applications. Phase separation, compatibility with gasoline, or salt contamination can influence many of the corrosion considerations. Vinyl esters as well as isophthalic and terephthalic resins (such as DION® 490) can display excellent resistance to ethanol and various blends with gasoline, of which E-85 (85% gasoline/ 15% ethanol) is a popular example. The superior resins display a high crosslink density. This directly increases the solvent resistance by restricting permeability or diffusion into the resin matrix. In addition, a high degree of crosslinking reduces any extraction or contamination of the fuel by trace components in the composite matrix, such as residual catalyst plasticizer or carriers. As always, good curing and post -curing will enhance resistance.