光電材料及元件製造業排放管道揮發性有機物排放特性之研究

The ozone is one of the major air pollution problem in Taiwan. The VOCs and NOX are the precursors of ozone formation. In Taiwan, the opto-electrical industry is a major business. The VOC emssions from opto-electrical industry is the third large emission inventories in total emission amount and the first large emission inventories in unit emission. Especially, some of VOCs emitted from the opto-electrical industry have high Maximum increment reactivity (MIR) of ozone formation. To improve the air quality, Taiwan Environmental Protection Administration have made some rule to require theowners or operators of stationary sources to reduce the VOC emssions and install continuous emission monitoring system (CEMS) for some significant emission inventories. Some VOCs used and emitted by the opto-electrical industry are high boiling point and highly viscose. They are easily stick on the sampling lines of CEMS and result in the inaccuracy measurment. Besides that, to meet the requirement of VOC emission standards, most of the owners or operators setup the regererative thermal oxidizers (RTO) to reduce the VOC emissions. The VOC emission profile for some type of RTOs have periodical high emission peak. There will be one significant problem from time-sharing CEMS to monitor the VOC emission from RTOs, it maybe could not get the complete VOC emission profile. To clarify the problems, this study is carried out to investigate the effect of the temprature of sampling lines, different reference methods (NIEA A723.72B and NIEA A433.71C) and the materials of sampling line on the VOC emission profiles. The results show that, the measured VOC concentration is different between the VOC CEMS setup by the owners or operators and the reference methods. For the case of high emission concentration, the VOC concentrations measured by CEMS are significantly lower than that of refence methods. The effect of sampling lines’ temperature on VOC concentrations is significant. The VOC concentrations measured by the reference methods with higher temperature of sampling lines are 50 ppm higher than that of lower temperature of sampling lines. In the case of higher temprature of sampling lines, the difference of VOC concentration measured is slightly between stainless steel (SS) tubings and Teflon tubings. However, in the case of lower temprature of sampling lines, the VOC concentration meseaured by using SS sampling tubings is lower than that of Teflon tubings.