Released Volatile Organic Compounds in Southern Yellow Pine before and after Heat Treatment

Abstract

As the main material in indoor furniture, southern yellow pine (Pinus spp.) releases volatile organic compounds (VOCs) into the environment during use. To better understand variations in the contents of VOCs in southern yellow pine before and after heat treatment, this study conducts dry heat treatment on southern yellow pine at 140 °C and 220 °C. Headspace solid phase micro-extraction was used to extract VOCs from southern yellow pine. The VOCs of southern yellow pine before and after heat treatment were identified via gas chromatography-mass spectrometry, and chemical component differences were characterized via Fourier transform infrared spectroscopy. Results reveal 86 VOCs in pure southern yellow pine, including alcohols, aromatics, acids, aldehydes, alkanes, alkenes, and some trace compounds (e.g., furans, ketones, phenols, and esters). With an increase in heat-treatment temperature, the contents of alkanes increased, whereas those of alcohols and alkenes decreased. The contents of aromatics, acids, and aldehydes were highest when heat treated at 140 °C. At 220 °C, the total contents of key VOCs in southern yellow pine were lowest.

Volatile Organic Compounds Emitted From Untreated and Thermally Modified Wood - A Review

“…wood, where the number of VOCs increased with heat treatment temperature, although the total VOC quantity emitted is decreased in thermally treated softwoods. There were 86, 93, and 131 VOCs identified in untreated specimens, specimens heat treated at 140°C, and specimens heat treated at 220°C, respectively (Wang et al 2018).…”

“…Temperatures above 150°C alter the physical and chemical properties of wood permanently (Akgül et al 2007) and chemical changes of wood components lead to new products and byproducts, including VOCs that can be emitted from wood after the treatment. Most of the new (by-)products resulting from the degradation of wood polymers appear only above 200°C and are formed at treatment temperatures of 220°C and 230°C (Esteves and Pereira 2009;Poncsak et al 2009;Culleré et al 2013;Wang et al 2018). For example, decomposition temperature of hemicelluloses and cellulose are about 200 to 260°C and 240 to 350°C, respectively (Mayes and Oksanen 2003).…”

“…Thermal degradation of wood components (ie hemicelluloses, cellulose, lignin, and extractives) during heat treatment leads to the formation of new products and by-products, including VOCs that can be emitted from wood after the treatment (Esteves and Pereira 2009;Poncsak et al 2009;Culleré et al 2013;Wang et al 2018). Thus, the amount of VOCs, including acids, aldehydes, aromatics, alkanes, and some trace compounds (eg furans, ketones, phenols, and esters) increase with an increase in heat treatment temperature, whereas those of alcohols and alkenes decrease.…”

“…As the temperature increases to 220°C, hydroxyl and carboxyl groups react and form esters, in which content is increased, whereas alcohol and acid contents decrease. With increasing temperature, the alkane content also increases, presumably because of pyrolysis of hemicelluloses (Wang et al 2018).…”

Comparison on Reduction of VOCs Emissions from Radiata Pine (Pinus Radiata D. Don) between Sodium Bicarbonate and Ozone Treatments

“…Additionally, Jiang et al [8] stated that caproaldehyde and pentaldehyde in wood VOCs were highly sensitive to temperature. In a preliminary study, it was found that the main VOC content of southern yellow pine samples decreased the most when heat treatment was conducted at 220 • C [9]. However, the energy consumption of heat treatment in the wood industry is high, and it can cause other drawbacks including the change of surface color and decrease of mechanical strength [10].…”