Emission Factor Estimation Using Monte Carlo Simulation: Focusing on the Development of Dioxin Emission Factors in Cremation Facilities

Abstract

In this study, data from 23 domestic cremation facilities measured for 5 years (from 2016 to 2020) of 13 domestic cremation facilities was used to calculate the emission factors of dioxins (PCDD/DFs) of cremation facilities that use Liquified Natural Gas (LNG) as combustion fuel. We performed a statistical analysis for the first time to estimate the emission factor using limited measurement results from cremation facilities that are not easily accessible. We attempted to identify the emission concentration of dioxin as a representative persistent organic pollutants substance and developed a statistically based dioxin emission factor. The concentration of dioxins (PCDD/DFs) in the cremation facility ranged 0.001–4.440 ng I-TEQ/Sm³ with an average concentration of 0.719 ng I-TEQ/Sm³. The emission factor calculated using the 23 measured data showed 0.010–21.485 μg I-TEQ/Cremation. A Monte Carlo Simulation was conducted using probability density distribution and parameter estimation. Consequently, 10,000 emission factors were selected, and the Pareto distribution was predicted to be the most appropriate probability density distribution. The emission factor values through Monte Carlo simulation showed a minimum value of 1.490 × 10–08 μg I-TEQ/Cremation and a maximum value of 7816 μg I-TEQ/Cremation. The average value was calculated as 39.920 μg I-TEQ/Cremation. Each parameter of the Pareto distribution is shape parameter (α) 1.026, location parameter (μ) – 1.021, and scale parameter (λ) 1.021. As a result of this study, the median value of the cumulative density function was selected as a representative value for the dioxin emission factor of cremation facilities and the emission factor was 0.986 μg I-TEQ/ Cremation. The 95% confidence interval in the Pareto distribution was presented as 0.026 μg I-TEQ/Cremation to 36.216 μg I-TEQ/ Cremation.