Analysis and evaluation of mercury emissions as an environmental pollutant from Iran’s power sector

Thermal power plants are one of the most important sources of mercury emissions. Mercury deposition in nature has a negative implication on human health. According to Article 8 of the Minamata Convention, all parties are obliged to estimate mercury emissions from anthropogenic sources and provide the best available control technologies. In this research, the analysis of mercury emissions from Iran’s power sector has been illustrated using the UNEP toolkit and the STIRPAT model for the period from 2011 to 2021. The average amount of mercury emissions and mercury emission factor were estimated as 505.6 kg and 1.85 kg/TWh respectively. The average emission factor of mercury for natural gas, heavy oil and gas oil combustion was calculated as 0.05 kg/TWh, 14 kg/TWh, and 1.29 kg/TWh respectively. The average amount of the external cost of electricity generation due to mercury emissions was calculated as 2,616.67 US$/TWh and 5,931.11 US$/TWh in two scenarios with and without the minimum exposure threshold respectively. The results of the STIRPAT model, it was indicated that a one-percent increase in factors including population, the share of electricity generation from natural-gas consumption, and the share of electricity generation from liquid fuels consumption led to an increase of 14.83, 0.3 and 1.49 percent respectively in mercury emissions. In addition, as a result of a one-percent increase in factors including gross national product per capita, intensity of electric energy generation and the share of electricity generation using non-fossil sources led to a decrease of 4.8, 4.74 and 0.15 percent respectively in mercury emissions.