Development, testing and investigation of an innovative additive process for wood chips to reduce emissions from wood combustion (AddHEmi)
The complete thermochemical conversion of solid biogenic fuels (e.g., wood pellets, wood chips or wood logs) is associated with unavoidable release of (inorganic) particulate matter (PM) emissions, especially during the utilization in small- and middle-scale combustion appliances. As a result, especially in urban or densely populated regions, depending on the plant density and the user behavior, significant exceedances of the permissible limit values for PM emissions in the ambient air can occur.
In this context, the utilization of so-called additives shows a promising, fuel-oriented solution concept. The selection of suitable additives leads to a temperature-stable integration of the PM-forming elements from the biomass in the ash, thus, a significant reduction of the measurable PM emissions during the combustion solid biogenic fuels (e.g., wood chips) can be achieved. Occurring challenges are inter alia the technical or constructive implementation of the additive supply system, the appropriate dosage of the additives due to varying fuels or fuel qualities and the current legal or restrictive framework. Overall, a comprehensive ecological, economic and technical analysis approach needs to be chosen.