Many power and recovery boilers out there are 20 to 30+ years old, running on oil or other fuel sources. Since 2010, when natural gas prices became attractive, Valmet has rebuilt several boilers to burn natural gas, resulting in energy savings and a cleaner boiler area for our customers.
A typical boiler gas conversion rebuild would include new burners, new igniters and a new fuel delivery train (skids). Valmet has performed these rebuilds for several years, about once a year, and we bring our decades of recovery boiler and power boiler experience to bear on each project – making sure the rebuild is on time and a custom fit. No two installations are the same.
We have converted recovery boilers only, both recovery and power boilers, and power boilers – depending on the desired scope and savings of the mill or power plant. Of course, every job, particularly recovery boilers, installed by Valmet follows NFPA code 85 for the care and handling of fuels (liquid, solid and gas) including design phase considerations.
Changing from fuel oil to natural gas will result in a cleaner boiler house with no leaks and messes. As far as the environment is concerned, the released emissions are lower with natural gas than with fuel oil. For a recovery boiler, an added benefit is that when Valmet completes a retrofit, from heavy fuel oil to gas, all the equipment that would clutter the boiler near the burner area is gone. There will only be a flexible hose near each burner – thus making it easier for operators and maintenance personnel to access the unit.
A fluidized bed boiler power plant refurbished by Valmet in 2016 with natural gas burners is "very happy because they are running much lower than expected for NOx emissions – well below permitted levels," says Ed Harris, Valmet's Process Engineer for power boiler projects.
Other recovery boilers which had been running oil for 20-30 years "were initially like walking into a chamber of horrors," according to Carlos Rollan, Valmet's Recovery Boiler Project Manager. "After the rebuild all the oil firing equipment is gone and the customer is left with a much simpler and cleaner system," he continues. So it's not surprising that mills have expressed satisfaction that the projects have been successful and they are convinced it was the right thing to do!
When changing to natural gas there are several issues which must be evaluated. Valmet can help you analyze your options step-by-step. Click HERE to learn more.
Regardless of your boiler original equipment manufacturer or current fuel source, Valmet is ready to assist you in achieving safer, lower cost boiler operations. Contact your Valmet representative.