Corrosion Issues in and Materials for Power Plant APC Systems is Hot Topic Jan. 6 & 7, 2011
NOTE: Because of the strong interest in this subject and the number of speakers, we have split this Hot Topic Hour into two sessions. Persons that register for the Hot Topic Hour will be able to attend both sessions.
Preventing and controlling corrosion has always been a challenge for power plant designers and operating personnel. Corrosion occurs in virtually every component of the typical coal-fired plant from the material handling systems, the boiler and ducts to the auxiliary systems for heat recovery and scrubbers and baghouses for pollution control all the way to the stack as well as the wastewater treatment system. Corrosion is both a chemical process and a physical mechanism. The chemical composition of the coal (chlorine and sulfur content) and additives to control pollution and wastewater affect the potential for corrosion. The distribution of gases in ducts as well as temperature, water content and particulate load contribute to mechanical flow corrosion caused by abrasion and build up of corrosive materials in a specific place in a duct or vessel.
Over the years, many methods have been developed to fight corrosion. These include a variety of new materials for ducts, liners, tubes and even pumps and valves, flow modeling and duct designs to minimize flow corrosion and injection of chemicals to control acid gases. Perhaps the single most important issue is to initially select the correct material for each application based on the environment that it is expected to operate in. During the last decade, Fiberglass Reinforced Plastic (FRP) composites have become very popular for use in scrubbers, tanks, pipe and stack liners because of their inherent resistivity to acids and lower cost compared to exotic metals. However, with the cost of FRP polymers going up and with the price of oil expected to continue rising in the future, is FRP still the best choice? Are metals, ceramics or glass now a better choice? Which material is best for each specific component in each air pollution control device?
The following speakers will discuss the latest developments in materials for corrosion prevention or reduction for the various APC equipment in a typical coal-fired plant based on plant specific site conditions, capital cost, maintenance and life time and provide an update of the current developments, on-going testing or performance of installations of corrosion resistant materials or new technology being developed at their respective companies.
The speakers on Thursday, January 6th will be:
Ben R. Bogner, Market Specialist at AOC Resins LLC, will discuss FRP Composites for the Power Industry. The recent growth in flue gas desulfurization (FGD) projects at power plants around the world has spurred the use of Fiberglass Reinforced Plastic (FRP) composites to contain and handle the corrosive liquids and gases. Air quality regulations in most countries require that sulfur dioxide from coal-fired power plants be removed before the combustion products are vented to the atmosphere. FRP has been selected for use in numerous sections of the FGD portion of coal-fired power plants; this paper will discuss the parts of the power plant that benefit most from the use of FRP. The thermal resistance, chemical resistance, cost and durability issues associated with FRP will be discussed and along with three case histories of applications in the power industry.
Dr. Deba Maitra, Research & Technology, Special Metals Corporation, will discuss their recent experience with stainless steels in FGD air pollution control service. Over the years, many materials have been used in the construction of components of wet limestone flue gas desulfurization (FGD) air pollution control systems ranging from duplex and austenitic stainless steels to highly alloyed grades of nickel-base corrosion-resistant alloys. Some recently constructed systems have experienced severe corrosion problems after short-term operation, in some cases in less than one year. To better understand the corrosive attack and the conditions under which various materials may be used, operating systems were examined and both laboratory and field tests were conducted. While the duplex steel was severely attacked by the environment, super-austenitic stainless steel and nickel-base alloy specimens were much more resistant.
Devin Wachowiak, Applications Engineer at Rolled Alloys, will discuss the successes of AL-6XN and ZERON 100 in the FGD industry. Alloys have been used in Flue Gas Desulfurization (FGD) Units for many years with many successful installations. AL-6XN and ZERON 100 are two of those alloys that have over 20 years of service experience in FGD environments at several power plants and used for many different applications within the FGD Unit. This presentation will review these past experiences to highlight the dependability of these alloys in the corrosive conditions of an FGD Unit.
The speakers on Friday, January 7th will be:
Joe Vandiver, President of Cera-Corr Systems, will present a new option for improved performance with proven materials science technology. Cera-Corr now offers the industry's first real choice in designers and constructors of monolithic, ceramic tile lined, reinforced concrete scrubber vessels (aka Stebbins Type). In addition, Cera-Corr deploys it's ceramic tile lining technology in concert with proven flake glass reinforced laminate resin lining systems for cost/performance optimization. Cera-Corr Systems combines the resources of leading engineering, technology and construction resources to take the risk out of corrosion control decisions for FGD scrubbers by delivering total customer driven solutions with well documented materials performance.
Don Kelley, Senior Scientist at Ashland Performance Materials, will give a brief overview of the use and reliability of FRP (Fiberglass-Reinforced Plastic) in power plant wet FGD applications. Fiberglass-Reinforced Plastic (FRP) made from Epoxy Vinyl Ester Resin will be compared to acid brick-lined carbon steel, stainless steel and high alloy clad carbon steel. Factors such as cost, maintenance and the avoidance of issues with FRP will be discussed.
Paul Nederlof, Vice-president, Sales & Operations for Hadek, will discuss linings for chimneys and other areas subject to corrosion and temperature.
To register for the "Hot Topic Hour" on January 6th and 7th, 2011 at 10 a.m. CST (Chicago time), click on: on: http://www.mcilvainecompany.com/brochures/hot_topic_hour_registration.htm
Bob McIlvaine
President
847 784 0012 ext 112
rmcilvaine@mcilvainecompany.com