Abstract
This thesis presents application of optical remote-sensing technology in monitoring trace gaseous pollutant at a refinery plant in Kaohsiung. UV-differential optical absorption spectrometry (UV-DOAS) is promising technique to detect aromatic hydrocarbons with high sensitivity. The method detection limit (MDL) for toluene, benzene, p-xylene, and ethyl benzene are 1.75 ppb, 0.5 ppb, 1.09 ppb, and 0.6 ppb, respectively. For other gases such as NO2, SO2, and formaldehyde, the MDLs are 0.80 ppb, 0.77 ppb, and 3.42 ppb, respectively. Overall, UV-DOAS shows precision of 0.5%-1% and accuracy of 85%-115%, indicating that it is a good technique to probe these organic and inorganic pollutants.Our laboratory has applied DOAS to conduct one-week continuous measurement in the refinery plant. With the combination of local meteorological information, including wind direction and wind speed, the results clearly showed that the concentrations of aromatic compounds were higher at night than in daytime, and that the major sources of these species were Naphtha cracker, aromatics extraction, and oil tank areas. During the one-week monitoring period, the average concentration of benzene, toluene, p-xylene and ethyl benzene were found to be 114 ppb, 139 ppb, 4.74 ppb, 2.04 ppb, respectively. Benzene and toluene exhibited higher abundance in the plant. Unlikely NO2 and SO2 were mainly emitted from chimneys in the producing area, and their average concentrations (35.67 ppb for NO2; 38.71 ppb for SO2) were not very high in the plant. There exhibited an apparent correlation between the variation of ozone started to increase from 9 AM and reached a maximum at 2 PM. The results indicated that, in addition to benzene and toluene, ozone was also a serious pollutant.