Coal-to-biomass conversions have become more popular over the past decade as coal has experienced tougher regulation and increased competition from natural gas and other sources.
To prolong the operational lifespan of a coal plant, utilities have converted some of their production capacity to biomass, either in a 100% conversion or a co-firing arrangement with both biomass and coal.
Currently, white wood pellets are the primary source of fuel for coal-to-biomass plants, but using this fuel source comes with often-steep capital requirements in the form of infrastructure. This infrastructure typically includes covered storage, dedicated receiving and material handling equipment, and systems designed to mitigate the risk of fire from dust that’s generated from the material.
There is a new technology being developed, however, that can make coal-to-biomass conversions more affordable from a capital standpoint: advanced wood pellets.
Advanced Wood Pellet Technology Explained
Advanced wood pellets are pellets that are treated to increase resistance to the elements, reduce the chance for fire or explosion, cut down on the amount of dust generated, and increase stability and integrity.
There are two main ways to create advanced wood pellets: torrefaction and steam treatment. Torrefaction involves applying heat to change the structure and composition of the wood pellet, while the other method uses steam.
The outcome of both of these technologies is a wood pellet that doesn’t require covered storage or specialized handling and dust control equipment. Advanced wood pellets are also more stable, more hydrophobic, more durable, and more resistant to temperature, meaning they can be processed at higher temperatures.
The bottom line impact is that advanced wood pellets can be handled in a way that is less capital-intensive – and less dangerous – than traditional, air-dried white wood pellets.
The Impact on a Coal-to-Biomass Plant
The main reason coal plants don’t convert partially or fully to biomass is due to capital cost. It can be expensive to create new infrastructure to handle basic wood pellets. But with advanced wood pellets, the conversion process requires less capital because there is a minimal amount of modification that has to occur in order to use this fuel as a replacement for coal.
One plant in Ontario moved one unit to 100% biomass with a $30/kW capital cost by using steam-exploded advanced wood pellets, which is a successful example of how this technology can be used to scale up at a commercial level.
As technologies like this continue to progress, more utilities will look to biomass as a way to enhance the production capabilities of their coal plants while also staying within regulations and making the entire process more economical.
ProcessBarron specializes in coal-to-biomass conversions, including designing, engineering, fabricating, and installing equipment to give a coal plant biomass-firing capabilities. Contact the team to learn more.