Air pollutant dispersion modeling :: A Case study of environmentasl impact assessment of PLTU 2 Jawa Timur
PRATAMA, Dian Septiani, Dr. Eko Sugiharto
2007 | Tesis | S2 Ilmu KimiaTelah dilakukan studi pemodelan dispersi polutan di udara sebagai alat pendukung untuk memprediksi dan menilai dampak di dalam Analisis mengenai Dampak Lingkungan (AMDAL) Pembangkit Listrik Tenaga Uap (PLTU). PLTU yang akan dibangun adalah PLTU 2 Jawa Timur kapasitas(1 × 600-700) MW, dengan konsumsi bahan bakar batubara 252 ton/jam. Lokasi PLTU ada di tepi pantai, dengan kontur perbukitan di sisi selatan. Studi pemodelan dilakukan berdasar modeling analitik-Model Plume Gaussian, dan skenario terburuk (asesment level 1). Parameter-parameter model meliputi laju emisi, ketinggian cerobong, teknologi kontrol polutan, geografi and meteorologi. Laju emisi dihitung dari data sampling cerobong PLTU yang sudah beroperasi (PLTU Paiton I, II), dan faktor emisi yang dikembangkan oleh USEPA. Ketinggian cerobong yang dimodelkan adalah 118.5 m, 200 m, 240 m, dan 260 m. Teknologi kontrol polutan yang dikembangkan adalah Over fire Air, Low NOx burner, Flue Gas Desulphurization, dan Electrostatic Precipitator. Skenario pemodelan yang terkait dengan parameter geografi adalah: karakteristik permukaan (pedesaan), kontur komplek dan kontur simpel, serta fumigasi pantai. Skenario meteorologi dimodelkan untuk semua kelas kestabilan atmosferik Pasquil. Arah penyebaran polutan dimodelkan dengan menggunakan data monitoring selama 5 tahun. Hasil pemodelan menunjukkan bahwa faktor yang paling berpengaruh adalah kontur kompleks (perbukitan) di sekitar lokasi PLTU, dibandingkan kontur simpel serta letak PLTU yang ditepi pantai (fumigasi pantai). Rasio konsentrasi maksimum yang diterima reseptor pada 0 km (konsentrasi ground level) antara skenario simpel, komplek dan fumigasi bervariasi, dipengaruhi oleh ketinggian cerobong, yakni 1 : 11.3 : 4.1 (tinggi cerobong 118.5 m), 1 : 6.5 : 2 (tinggi cerobong of 200 m), 1 : 6.8 : 1.7 (tinggi cerobong of 240 m), and 1 : 7 : 1.6 (tinggi cerobong of 260 m). Strategi kontrol polutan memberikan performa terbaik bila seluruh teknologi kontrol polutan untuk NOx, SOx, dan Pm digunakan serta batubara yang digunakan mempunyai kadar sulfur rendah. Strategi peninggian cerobong kurang efektif, peninggian cerobong dari 200 m menjadi 240-260 m hanya menurunkan 2.8% konsentrasi maksimum (skenario kompleks). Arah penyebaran polutan cenderung ke arah selatan dan barat.
The air pollutant modeling studies was performed as a supporting tool for new power plant Environmental Impact Assessment (EIA). The power plant which proposes as pulverized coal fired steam, with coal consumption rate of 252 ton/h., is PLTU 2 Jawa Timur (1 × 600-700 MW). The power plant’s site is near the seashore with a complex terrain environment in the South side. The modeling studies were performed with analytical modeling-Gaussian Plume Model, and under the worst scenario (Level I assessment). The model parameters were used consist of : emission rates, stack height, control pollutant technology, geography and meteorology. The emission rates were calculated from stack sampling data from existing power plant (PLTU Paiton I, II), and emission factor that developed by US-EPA. Stack heights were modeled for 118.5 m, 200 m, 240 m, and 260 m. Control pollutant technologies were modeled for Over fire Air, Low NOx burner, Flue Gas Desulphurization, and Electrostatic Precipitator. Modeling scenarios with relation to geographical parameter were: modeled for surface characteristic (rural), complex terrain, simple terrain, and shoreline fumigation scenarios. The meteorology scenarios were modeled for all Pasquill’s atmospheric stability scenarios. The direction of air pollution dispersion was modeled from five year monitoring meteorological database. The modeling results show that the complex terrain feature is the most influencing factor to the dispersion of air pollution, rather than simple terrain and shoreline fumigation. The ratios of the maximum concentration received by receptor at 0 km (ground level concentration) between simple terrain, complex terrain and shoreline fumigation are varied with the stack height. The ratios are: 1 : 11.3 : 4.1 (for the stack height of 118.5 m), 1 : 6.5 : 2 (for the stack- height of 200 m), 1 : 6.8 : 1.7 (for the stack height of 240 m), and 1 : 7 : 1.6 (for the stack height of 260 m). The control strategies give the best performance if the entire control device for NOx, SOx, and Pm were applied, and coal with low sulfur content was consumed. Increasing the dispersion by increasing the stack height up to 240 or 260 m did not give a significant distinction with 200 m height, it just decreasing the maximum concentration to 2.8 % under complex terrain scenario. The direction of the pollutant dispersion is prone to the South side and the West side.
Kata Kunci : Pemodelan dispersi polutan di udara, model Gaussian Plume, AMDAL, PLTU, kontur perbukitan, fumigasi, Air Pollution Modeling, Gaussian Plume Model, EIA, Coal Fired Steam Power plant, Complex terrain, Fumigation
