Thermochemical recovery of waste wood in a domestic wood stove: influence of the geometry of wood batch in the fireplace on pollutant emissions

In the current energy context, pallet boards represent a wood of opportunity strongly used on an individual scale as a means of heating at a low cost. However, French stoves are certified to burn only hardwood species. The main objective of this work is to study the combustion behavior of pallet boards in a commercial stove designed to burn hardwood. The novelty of this work lies in the study of the influence of the wood surface exposed to fire and the identification of the conditions that promote the production of ultrafine particles. The results of the combustion tests show that the surface exposed to the fire influences the combustion. Of the six wood dispositions tested, two stand out with gaseous and particulate emissions at similar levels of a conventional hornbeam log and a densified log. Low temperature conditions and high levels of unburned gaseous products were identified as promoters of ultrafine particles. Overall conclusion of the study is that it is possible to use pallets in a non-designed stove, provided that the user carefully manages the combustion. This opens the way to the clean and rational use of a new type of fuel in a low carbon circular economy.