VietNamNet Bridge – The country’s thermal power plants generated up to 12.2 million tones of coal ash last year, while treating only 4 million tonnes, meaning inventory rose to 25.2 million tonnes, according to the Department of Industrial Safety and Environment (DISE) under the Ministry of Industry and Trade.

A coal conveyor belt is covered to avoid releasing ash into the environment at a thermal power plant of the Duyen Hai Power Centre in the southern province of Tra Vinh. — VNA/VNS Photo Phuc Son

The amended master plan for electricity development for the 2011-2020 period with a vision to 2030 says that 52 coal-fired power plants will be in operation by 2030 with a total designed capacity of 52,252 MW. So in the next few years, if no solutions are developed, the amount of ash could increase so much that there is no room for storage.

Deputy director of the DISE, Pham Trong Thuc, said that the generation of thermoelectricity was one of the biggest sources of waste.

To produce 1kWh of electricity using coal dust, from 0.9 to 1.5kg of coal ash will be emitted. Thus, coal ash generated annually from the 23 operational thermal power plants measures about 12.2 million tonnes. The north of the country is home to 60 per cent of the plants, while the central region has 21 per cent and the south 19 per cent.

Therefore, it was important to have an accurate assessment of this risk in order to develop a comprehensive and efficient policy for the management, transportation and disposal of coal ash from thermal power plants, he said.

He added that although the Government and ministries encouraged the use of coal ash and boiler slag for the production of cement and other materials in construction, the amount of ash had increased rapidly because the production process faced obstacles and products were difficult to sell.

The first reason was that most people and construction enterprises are wary of the quality of unburnt brick made from coal ash.

Additionally, the country lacked technical regulations for the treatment and use of coal ash and boiler slag in construction, while many legal documents on management are not suitable. For example, at the Dong Trieu Thermo Power Plant in Quang Ninh, the average annual output of Mao Khe Thermal Power Plant is about 650,000 tonnes of ash. However, only about 17 per cent of the ash is used in the production of non-baked materials and as a cement additive.

Associate Professor Bach Dinh Thien, an expert from the Tropical Building Materials Research Institute said that if coal ash and boiler slag were treated well, Vietnam could save millions of tonnes of minerals per year.

The Ministry of Construction has issued Circular 13 regulating the use of unbaked building materials, which took effect from the beginning of February this year.

Under the circular, enterprises in Hanoi and HCM City must use 100 per cent of unburnt building materials. Enterprises in lowland, midland and south eastern areas must use at least 90 per cent, and in the remaining areas at least 70 per cent.

In March this year, Deputy Prime Minister Trinh Dinh Dung worked with concerned ministries to discuss solutions for processing coal ash and boiler slag, and resolve difficulties towards creating more favourable conditions in the management, use and consumption of ash and slag.

Source: VNS