Reducing ash-related operational problems in waste wood combustion

Waste wood combustion has become common practice in many EU member states. However, waste wood often contains elements increasing the risk to get problems in the boiler, including severe ash deposition leading to often substantial corrosion problems in the superheater as well as on furnace walls that cause unacceptably short life times.

A possibility to reduce alkali chloride-related corrosion problems is to use various additives. Several different mineral- and sulfur containing additives have been proposed, but these have so far mainly been tested on laboratory scale tests only (while more in-situ and industrial scale tests are preferred) and there is still a clear need for further development in several areas, including studies of new cheap and resource efficient fuel additives for reducing corrosion/fouling/slagging.

The overall objective is to improve economic and environmental conditions and enlarge the market for the use of wood waste fuels in CHP-plants by using resource efficient additives such as recycled gypsum during combustion. A specific aim is to show how fuel additive design concepts are related to reduced operation and maintenance-costs (O&M costs), which ultimately should lower required SDE+subsidy levels for waste wood combustion.