Volatile Organic Compounds Arising from Wood Polymers on Thermal Loading of Spruce Wood

The thermal degradation of wood polymers (cellulose, hemicelluloses, and lignin) results in the production of volatile products, some of which are toxic or act as irritants. In the present work, we focus on the effect of wood treatment on the formation of volatile products, conducting experiments on thermally treated (TTW), flame-retardant-treated (FRW), and untreated (REF) spruce wood. The samples were subjected to thermal loading at 150 °C, 200 °C, and 250 °C with the subsequent collection of degradation products. We evaluated the effect of wood treatment on the formation of volatile organic compounds (VOCs) using gas chromatography-mass spectrometry (GC-MS). The number and quantity of VOCs are significantly affected by the type of wood treatment and the thermal loading temperature. At the temperature of 250 °C, the concentration and number of VOCs increased significantly. The highest number of VOCs was identified in the untreated wood samples (54 compounds, mostly aldehydes, ketones, and phenols), with a lower number being identified in the flame-retardant-treated samples (9 compounds, mainly furfural) and the lowest number being identified in thermally treated wood samples (3 compounds, aliphatic hydrocarbons). Typical volatile products included furfural, furfurylalcohol, and α-pinene. Qualitative and quantitative analysis of VOCs under thermal loading is important in evaluating the wood burning process and the toxic properties of the consequent gaseous products.