TRENDS IN STEAM-GENERATING SYSTEMS FOR THE FOREST PRODUCTS INDUSTRIES

With a variety of challenges, new and old, the powerhouse department is forced to develop new degrees of freedom for itself to fight those challenges. Some new degrees of freedom, such as alternative fuels, are themselves challenges. The existing hardware can, in some cases, be put to better use with fuel modifications, such as total or partial drying, sometimes combined with suspension firing. Improved controls and monitoring systems seem to have ultrashort paybacks. New boiler plants have to apply relatively sophisticated combustion and emission control methods to meet stringent emission requirements, whereof NO//x is often the limiting factor. Fluidized bed firings possess many of the desired features, especially if fuels other than wood are considered. New fuels are in the offing: in some areas, orchard prunings and other agricultural waste are no longer incinerated in the field and are becoming available as fuels.