Many coal-based power plants have increased their emissions control because of regulatory requirements. One of the emissions output that is watched very closely by regulatory agencies are sulfur dioxide (SO2) gases.
Investments in new equipment for removing SO2 emissions can be very costly and coal power plants are looking for ways to meet the regulatory requirements without having to replace emission control equipment because of corrosion and erosion issues that are inherent with coal burning power plants, including chloride corrosion.
To achieve these SO2 emission requirements many plants are using spray-dryer absorber (SDA) scrubbers, which include a rotary atomizer that uses slurry with slaked lime – or milk of lime – where the SO2 is absorbed by Ca(OH)2 to form CaSO3/CaSO4. Most of the absorption takes place in the SDA chamber, where an enormous number of atomized lime milk droplets are intimately mixed with the hot flue gas to ensure complete drying of the droplets before they hit the SDA chamber walls.
One coal power plant, the Antelope Valley Station, near Beulah, North Dakota, operated by Basin Electric Power Cooperative, has extended the life of their SDA scrubbers by utilizing IGS for installation of a corrosion prevention surface protection system. The Antelope Valley plant is fueled by lignite coal. It uses SDA scrubbers to reduce SO2 emissions.
Integrated Global Services (IGS) worked with Antelope Valley, as they have with other power plants, pulp & paper mills and oil & gas refineries to create a cost effective turn-key solution to a customer problem of metal wastage in critical process equipment. IGS provides customers with proprietary cladding materials and application, mechanical repair, welding, and other outage maintenance services required to achieve greater life expectancy of equipment with highly corrosive or erosive processing conditions.
Duane Miller, scrubber / fuels supervisor at Basin Electric’s Antelope Valley Station, said: "The SDA Scrubber is a critical piece of equipment needed for our SO2 emissions control and regulatory compliance. Preventative maintenance is a critical component of our operations. Working with IGS to create a turnkey program to extend the longevity of our SDA chambers has been essential towards ensuring our availability, reliability, and maintaining our SO2 emissions permit requirements.
"IGS provided a quality job and other coal fired power plants, like the Antelope Valley Station, have inquired about our cladding experience with IGS and how we expected this to extend the life of our SDA chambers."
IGS is the leader in the technological innovation and application of surface protection systems to solve corrosion problems in challenging operating environments. IGS designs solutions that increase plant reliability, increase equipment availability, and reduce unplanned downtime. IGS has its own accredited Technology Research Center in Richmond Virginia, USA, dedicated to the ongoing research and design of on-site and shop applied Metalspray®, ceramic coatings, and automated weld overlay systems.
IGS solutions are designed by coupling its extensive evaluation process with the largest database of erosion and corrosion test results in the world, unmatched global industry experience, and partnerships with some of the most advanced research and customer-sponsored laboratories in the world.