| 초록 |
Emission characteristics of volatile organic compounds (VOCs) were investigated in the flue gas emitted from wood drying process for plywood manufacturing. The moisture content of raw timber was average 48%, and its density was $831.55kg/m^3$ . But the moisture content of dried wood is needed less than around 10%, thus the moisture contents of flue gas should be remarkably high(about 18.2 V/V%). Therefore, the vapor in flue gas is equivalent to 320 ton-vapor/day when 1100 ton-wood/day is treated in the wood drying process. The temperature of flue gas ranges from $140^{ circ}C ;to ;150^{ circ}C$ in each dryer stack with exception of the input site of wood(about $110^{ circ}C$ ). The velocity of flue gas in each stack ranges from 1.7 to 9.7m/sec. In order to assess the concentrations and attribution rate of odorous compounds, it was analyzed about 40 VOCs in the flue gases. It was found that the major odorous compounds were 8 compounds, and the concentrations of major VOCs(ppm) were as follows; benzene: $0.054{ sim}0.052$ , toluene: $1.011{ sim}2.547$ , ethylbenzene: $0.472{ sim}2.023$ , m,p-xylene: $0.504{ sim}3.245$ , styrene: $0.015{ sim}0.148$ , o-xylene : $0.271{ sim}1.097$ , ethanol: $11.2{ sim}32.5$ , ${ alpha}$ -pinene: $0.908{ sim}10.578$ , ${ beta}$ -pinene: $0.982{ sim}14.278$ . The attribution rate of terpenes ( ${ alpha}$ -pinene, ${ beta}$ -pinene) was about 60.56%, and that of aromatics and alcohols was about 22.77%, and 16.67%, respectively. It is suggested that the adequate control device should be used to control both the water soluble and non-soluble compounds because both compounds were mixed in flue gas. |
