Tackling corrosion prevention in the power industry can be a challenge. Engineers at Enron Power Corporation, Houston, Texas, solved this dilemma by carefully choosing an FRP pollution control lining formulated to withstand the everyday demands of their cogeneration system, while also providing a solid return on their investment.

According to Jon Stroble, project manager for Enron Power Corp-US, the challenge of choosing a suitable tank lining began in July of 1988, when employees discovered the need to line a steel neutralization tank.

Stroble decided to line the tank, as well as two others comprising the cogeneration system, with Armor Plate® 700 from Wil-Cor Inc., Pasadena, Texas. He notes that two of the three storage tanks measure 40′ x 40′, and the third tank measures 40′ tall x 36′ in diameter.

According to Stroble, the first tank neutralizes water ranging in pH from 4-12, operating at temperatures up to 100°F. The second tank that was lined stores lime-softened water at a maximum temperature of 100°F. The third tank, which is in condensate service, stores demineralized water at a temperature range up to 180°F. In addition, Wil-Cor lined a concrete containment area containing 98 percent sulfuric acid and caustic pumps using Armor Plate® 700 FRP lining top-coated with Armor Coat® 969 Plus.

“We extensively considered the demands placed upon each tank and decided that the FRP lining was the appropriate choice for this application,” notes Stroble.

Fred Wilson, president of Wil-Cor, agrees that the lining offers excellent capabilities to withstand this environment. “We recommended Armor Plate®because it’s formulated with DERAKANE 411-45 resin,” he says. “We knew this lining would provide the highest performance available to protect the tanks against the corrosive nature of this service.”

Before beginning the lining process, Wil-Cor fabricated a storage tank to serve as a temporary replacement vessel for each of the three tanks as they were taken out of service one at a time.

Wil-Cor began fabrication by sandblasting the surface of the tanks to near white metal and priming the surface with Armor Plate® 784, which is also formulated with DERAKANE resin. The linings were then applied by hand lay-up using 1.5 chopped strand may and a layer of Nexus®

Wilson says a major challenge during the lining process was managing the Gulf Coast summer temperatures.

“We applied the linings in July, working in more than 100°F temperatures. Therefore, we monitored the internal temperature of the tanks very closely to ensure that the process was completed correctly,” Wilson notes.

Stroble adds that the end result is quality pollution control. After four years of service the linings are still in good condition, protecting the steel tanks from everyday wear and tear and providing a solid return on Enron’s investment.

“We made the right decision to use the Armor Plate® formulated with DERAKANE resin. The tanks are holding up well, and we believe we have gotten our money’s worth,” he says.

Stroble adds that Enron plans to contract Wil-Cor to apply the same lining material in another cogeneration system at their Massachusetts plant.

He says, “We’ll be building two tanks this fall — one will hold demineralized water and the other is a neutralization tanks, which will be exposed to the same pH swings as the tank in Texas. Since we’ve been successful with this project, we are looking forward to success in a similar application at other facilities.”