If you have been following CCJ’s coverage of film forming substances over the past several years (see recent article on FFS2024), you’re aware of the value of these chemicals in protecting metal surfaces. If not, you can come up to speed quickly by watching the four webinars on “Mastering Film Forming Amines” hosted by Ronny Wagner, managing director, Reicon Leipzig GmbH, which can be accessed on demand at the company’s website.
Reicon has more than 40 years of experience in research and application of Octadecylamin (ODA)-based film forming amines and Wagner is recognized worldwide for his work in this technology.
By way of background, filming amines and products provide corrosion protection by forming a physiochemical barrier between metallic surfaces and the working fluid (water) to prevent corrosion from occurring. Filming amines and products also can provide a film on steam-touched surfaces and offer protection against oxygen pitting when boilers are offline and exposed to humidified air or water formed via condensation.
What follows is an outline of topics included in each webinar to guide your involvement.
Webinar 1, Basics and guidelines (access)
- What is an FFA and what is not? Explains the differences among film forming amines, film forming amine products, and film forming products.
- How do FFAs work? The adsorption process is addressed first using simple diagrams to describe physisorption, chemisorption, and multilayering. Explanation of corrosion protection is next, then cleaning effect and impacts of droplet diameter and droplet condensation.
Final dozen slides in this webinar focus on FFS standards developed by the International Association for the Properties of Water and Steam (IAPWS), an organization respected by powerplant owner/operators. Its Technical Guidance Documents (TGD) are invaluable and available at no cost from www.iapws.org.
Webinar 2, Analysis procedures (access)
Focus is on the basics of FFA analysis: (1) What’s being measured, (2) Standards and guidelines available to guide your decision-making, and (3) Specialties for sample-taking.
Regarding the first point, keep in mind that only residual concentrations in water or steam can be measured. The only available guidelines today are IAPWS TGD 8-16 (2019), “Application of film forming substances in fossil, combined-cycle, and biomass powerplants” and TGD 11-19 (2019), “Application of film forming substances in industrial steam generators.”
Two laboratory analysis methodologies are mentioned: Extraction method with methyl-orange (Silverstein Method) and Xanthene dye reaction (Bengal Rose Method). For more information, see Section 8.5 of TGD8-16.
Field tests cited are the Lovibond Tablets Test, which is not suitable for concentration determination in FFA applications in steam and hot-water boilers, and the Chemetrics Filming Amine Test. The Waltron Filming Amine Analyzer is mentioned for online measurement.
Webinar 3, Continuous dosing under cycling operation (access)
Covers the application guidelines on (1) Possible injection points, shown on a cycle diagram, (2) Dosing recommendations for different operating scenarios, and (3) restrictions and challenges to keep your plant operating as intended. The last gives very specific guidance. For example, FFAs start to thermally decompose at temperatures greater than 750F.
Webinar concludes with two case studies of interest to plant operating teams—one a combined cycle in flexible operation, the other a biomass plant with seasonal peak-load operation.
Webinar 4, Preservation procedures (access)
Application guidelines are continued in this segment of the webinar and begin by answering the question: Why use FFAs for material preservation? Reasons include: Offline corrosion starts immediately following plant shutdown, pitting initiated by offline corrosion is a starting point for turbine damage, to reduce the amount of corrosion product transport during startup.
Ronny Wagner told webinar participants that four main factors influence the preservation effect: FFA concentration, time, temperature, and water quality. He then offered preservation procedures and highlighted restrictions and challenges to be aware of.
Webinar concludes like the previous one with two case studies—one discussing a coal-fired station with extended layup and the caveat that the 780-MW unit might have to restart quickly to provide grid support. The second unit was a 390-MW lignite-fired plant. Its preservation goal: provide capacity reserve in accordance with German law while protecting the water/steam cycle against corrosion for four years. The recommissioning time allowed is less than 10 days.
Photos shown during the presentation revealed that all observed surfaces continued to show hydrophobic behavior after two years of layup. There were no signs of corrosion in pumps or condensate lines; feedwater showed no evidence of rust.
