Impact of the type of particle boards on the nitrogen fate during their pyrolysis and combustion

Particle boards, wastes made out of wood particles bonded with nitrogen-rich adhesives, produce high NOx emissions during combustion, requiring control in biomass grate furnaces. However, the diversity of particle board feedstocks has often been overlooked, and the specific effects of different types have not been studied, despite accounting for over 10 % of the total volume. This work analyzes nitrogen behavior during combustion of standard, moisture-resistant, and fire-retardant particle boards. The combustion process was investigated as a whole, but also by proceeding separately to pyrolysis and char oxidation experiments. Thermogravimetric analysis and experiments conducted in a cross-fired fixed bed reactor were performed under both air and inert (N2) atmospheres. The nitrogen content in various combustion products (incondensable gases, condensates, and residual solids) was quantified to assess the impact of chemical treatments on nitrogen fate. Results showed that standard and moisture-resistant particle boards showed comparable combustion behaviors. Notable differences emerged during the combustion of fire-retardant particle boards, likely due to the influence of fire-retardant agents. In these cases, a slower heating rate within the bed and reduced hydrogen cyanide (HCN) emissions were observed compared to the other two types. Across all experiments, most of the nitrogen released was found in condensates • Moisture-resistant treatment has no effect on nitrogen release. • Fire retardant treatment lowers devolatilization temperature, increases char yield. • Fire retardant treatment lowers HCN production by lowering temperature in the bed. • Further investigation is needed to examine the nitrogen content of the condensates.