Thai Binh Thermal Power Plant in the northern province of Thai Binh. Experts have accused coal-fired power plants of causing air pollution in Hanoi - PHOTO: THANH NIEN

It was estimated that some 20% of fine dust PM2.5 in Hanoi came from large power plants and industrial zones around the capital city, the Vietnam Academy of Science and Technology and the International Institute for Applied Systems Analysis concluded in a report published in October 2018.

There are 20 thermal power plants in the north. Of these, Na Duong thermal power plant in Lang Son Province has the lowest capacity, at 110 megawatts, while the largest plant by capacity is in Quang Ninh Province, at 2,280 megawatts. Major power plants are located in Haiphong City and Quang Ninh.

According to Tran Dinh Sinh, deputy director of the Green Innovation and Development Center (GreenID), if a power plant having two generators of 1,200 megawatts uses the most modern electrostatic precipitator (ESP) to collect fine particles with an efficiency of 99.75%, the remaining 0.25% is equivalent to eight tons of dust being discharged into the environment, including over 2.3 tons of fine dust PM2.5.

Supposing that the ambient air was completely clean, the given amount of 2.3 tons of fine dust will pollute the air within a radius of approximately 65 kilometers and to a height of 200 meters. So, despite being equipped with the filtration device, the plant still discharges a substantial amount of PM2.5 into the air, Sinh reported.

He added that operations of coal-fueled power plants could potentially trigger air pollution, in spite of meeting the country’s environmental standards.

Manufacturing activities in industrial zones in Haiphong and Quang Ninh, chiefly powered by coal-fired power plants, was one of the major causes of deteriorating air quality in Hanoi, said Sinh.

However, coal-fired power plant operators have offered evidence to prove Sinh’s claim was wrong.

According to To Van Tiep, deputy head of the Technical Division at Thai Binh thermal power company, the air monitoring system documented how the plant’s gas emissions, after passing through a 215-meter-high chimney, would not affect areas outside a 10-kilometer radius of the plant.

The company’s Thai Binh thermal power plant, with two 300 megawatt generators, spent some US$70 million on an emission treatment system. It is equipped with an ESP with an efficiency of 99.98% and a flue gas desulphurization system to remove sulfur dioxide from exhaust flue gases, with an efficiency of 98.9%.

Similarly, the Nghi Son fossil-fuel plant also said it invested over US$1.2 billion in its gas emission treatment system. This resulted in gas emissions not having impacts on areas located five kilometers away from the plant, said Le Ngoc Minh, head of the plant’s Environment Safety Division.

However, air monitoring results from coal-fired plants have yet to ease environmental activists’ concerns over the negative impact of such plants on air quality. Sinh suggested that coal-fired plants be shut down to ensure fresh air reaches the capital city.

Also, the Government should hold a meeting where experts in the fields of environment, energy, and economy could attend and settle their disagreements over gas emissions from coal-fueled plants, advised Sinh. SGT