Emissions of volatile organic compounds in the Hsuehshan tunnel

• Main Authors: Po-Jui Chang, 張栢瑞
• Other Authors: Kang-Shin Chen
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/9m26rw

碩士 === 國立中山大學 === 環境工程研究所 === 96 === Hsuehshan tunnel which included two bore and three ventilation shaft systems is the longest (12.9 km) freeway tunnel in Taiwan. 56 species volatile organic compounds (VOCs) were sampled in two different locations each bore and three emitted shafts to determine the emission factors (EFs). Each sampling day has three sampling period: morning (8:00-10:00), Noon (12:00-14:00) and afternoon 16:00-18:00). C2 species were analyzed by GC/FID and C3 − C12 species were analyzed by GC/MS. The composition in southern bore was expressed by alkanes (36.69% − 39.20%), aromatics (34.14% − 36.33%), alkenes (20.27% − 21.95%), Alkynes (3.35% − 4.11%) and Naphthenes (1.06% − 1.35%). Northern bore had the similar profile. Ethylene (4.93 ± 2.21 mg/veh-km), Isopropane (4.85 ± 2.75 mg/veh-km), toluene (4.55 ± 1.31 mg/veh-km), m,p-xylene (2.98 ± 0.90 mg/veh-km) and propylene (2.70 ± 0.88 mg/veh-km) are the top five abundant VOCs in southern bore ; Isopropane (6.78 ± 3.33 mg/veh-km), ethylene (5.44 ± 2.63 mg/veh-km), toluene (5.32 ± 2.39 mg/veh-km), propylene (3.55 ± 1.67 mg/veh-km) and m,p-xylene (3.36 ± 1.45 mg/veh-km) are the top five abundant VOCs in northern bore. The EFs were smaller than other freeway tunnel investigated. Shaft emitted the partial mass of VOCs result in concentration gradient dropped off. The total VOCs EF of shafts during holidays was in the range of 72.24 mg/s − 180.60 mg/s higher than on weekdays in the range of 53.40 mg/s − 82.74 mg/s. The EF of shafts had effected by air-extracting apparatus, so standard deviations (S.D.) varied widely. Combining the EF of shaft with EF of tunnel we obtained the overall vehicle EF which was close to other freeway tunnel results. The proportion of Ozone formation potential (OFP) in both bore were alkenes (47.5% − 48.5%), aromatics (40.2% − 42.3%) and alkanes (9.8% − 10.1%). Note that sum of alkenes and aromatics exceeded 90%.