Smurfit-Stone installs CPVC pipe in corrosive bleach plant: an integrated producer of paperboard and paper-based packaging products chose plastic over metal for reliable performance.

When the U.S. Environmental Protection Agency (EPA) published the Cluster Rule in 1998, pulp and paper manufacturers began making operational adjustments to comply by April 2001. Aimed at reducing emissions, the Cluster Rule called for the introduction of uniform pollution prevention and control technologies. For Smurfit-Stone Container Corp., this meant a major expansion of its in Panama City, Florida, pulp and paperboard mill, including extensive changes to its bleach plant.

Smurfit-Stone retained BE&K Engineering Co., Birmingham, Alabama, to identify cost-effective construction materials that would provide reliable performance in this harsh environment. Specified materials including industrial piping had to demonstrate superior corrosion resistance that would prevent premature system failure. To complete construction on time to meet the tight deadline imposed by EPA, these products needed the added property of quick installation.

"In a bleach plant setting, corrosion can actually occur on the inside and the outside of piping," said Dennis Myers, principal engineer, technical group mechanical services, at BE&K. "The trick was finding a material that would address both types of corrosion satisfactorily."

For the recovery of the spent scrubber effluent of the bleach plant, BE&K specified Corzan[R] chlorinated polyvinyl chloride (CPVC) pipe from Noveon Inc., Cleveland, Ohio, rather than stainless steel, carbon steel, or fiberglass piping alternatives. Besides its superior property of corrosion resistance, the CPVC pipe offered last, easy installation and increased cost efficiency compared with its metallic counterparts, according to BE&K.

WITHSTANDING CORROSIVE ENVIRONMENTS

Corzan CPVC pipe is a reliable alternative for the transportation of corrosive chemicals, according to Noveon. CPVC piping has demonstrated excellent service in bleach-plant process lines even when exposed to several corrosive acidic and caustic solutions found in bleach preparation and process operations, the company said.

The effluent solution in this particular application results from combining weak white liquor with a mixture of gases containing chlorine dioxide residuals. With a pH of 9.9 and a temperature of 135[degrees]F, this solution can cause internal pipe corrosion that diminishes the service life of carbon steel and stainless steel piping materials.

CPVC pipe offers corrosion resistance inside and outside. "Considering previous performance in this harsh environment, a considerably longer service life from the CPVC pipe should result compared with carbon or stainless steel," explained Myers. "Plastic-lined FRP was another alternative, but CPVC offered advantages in simplicity, cost, and size availability that FRP could not match."

INSTALLATION AND MAINTENANCE

Inherently lightweight and easier to support than metallic piping systems, CPVC piping also allows for quick installation. Joining of the system can use solvent cementing, flanging, or threading rather than welding to reduce installation time.

"We had to begin operating this plant immediately. Using Corzan CPVC, we could install a reliable system while keeping the construction schedule on track," said Myers. "In addition, installation of a branch line or other piping modification is rapid with CPVC if necessary. If some piping should be damaged, the repair is easy because it does not require a welder or a lifting device to hoist the piping into place."

By combining superior mechanical properties and longer service life with lower installation and maintenance costs, CPVC gave BE&K the complete system solution necessary for Smurfit-Stone, said Myers. "Corzan CPVC provided us an excellent balance of qualities that produced quality, cost savings, and simplicity in this application," concluded Myers. "We are expecting excellent performance from the system for many years."

Smurfit Stone Container Corp. is an integrated manufacturer of paperboard and paper-based packaging. Noveon Inc., is a producer and marketer of specialty chemicals for consumer and industrial applications. Previously BFGoodrich Performance Materials, Noveon became an independent company in February 2001. For more information go to www.corzancpvc.com or call 1 888 234-2436.