[Smart Electronics Story] High-Efficiency Wet Scrubber Capturing Air Pollution from Thermal Power Plants

Pilot EME for domestic standard coal-fired power plants installed at Doosan Heavy Industries headquarters in Changwon, Gyeongnam

[Asia Economy Reporter Ki-min Lee]‘Agile Electronics Stories’ is a column that keenly examines small details about electronic and mechanical products and devices. We kindly cover hot new products frequently appearing in advertisements and news, nostalgic items, puzzling products and industry terms, and news with the heart of a beginner.

As environmental destruction and health issues caused by climate change and fine dust have emerged, low-carbon eco-friendly energy such as solar power and wind power is gaining attention. In particular, following the government’s announcement at the end of last year to reduce 90% of fine dust generated by coal-fired power plants and cut greenhouse gas emissions by about 25%, it recently accelerated its Green New Deal policy by pledging to shut down 20 additional coal-fired power plants by 2034.

The power generation industry is also making efforts to enhance eco-friendly power generation capabilities while attempting to reduce pollution from currently operating thermal power plants. Today, in ‘Agile Electronics Stories,’ we would like to introduce a high-efficiency Electrostatic Mist Eliminator (EME) that removes steam and fine dust from thermal power plants.

Existing coal-fired power plant chimneys are equipped with Flue Gas Desulfurization (FGD) facilities to treat exhaust gases, and a Mist Eliminator (ME) is installed and operated at the upper part of these facilities. The existing ME removes pollutant particles by either a centrifugal force method that strongly rotates the particles or an inertial collision method where particles are removed by colliding along pipes. However, the existing ME has a limitation in that it cannot properly filter ultrafine dust particles smaller than 20㎛. To remove pollutants that are not filtered at this stage, an additional wet electrostatic precipitator must be installed, which poses an economic burden.

EME Dust Collection Performance Test

[Image source= Doosan Newsroom]

By applying the EME method, most of the ultrafine dust and white smoke generated can be filtered by simply adding EME equipment to the FGD without the need for a separate wet electrostatic precipitator. The EME works on the principle of using static electricity to trap fine dust and other particles so they cannot pass through, then washing the fine dust downward with water coming from above. Installing EME eliminates the need to additionally install a wet electrostatic precipitator above the ME, making the equipment and management simpler.

Among domestic EME manufacturers, Doosan Heavy Industries & Construction, which is engaged in power generator manufacturing, is the most well-known. Doosan Heavy Industries & Construction was selected in 2016 as the lead organization for a national project by the Korea Energy Technology Evaluation and Planning (KETEP) in collaboration with the Korea Institute of Machinery and Materials to develop EME. Last year, they installed a full-scale EME suitable for domestic standard coal-fired power plants at Doosan’s Changwon factory and completed experiments, and are currently conducting demonstration work at domestic coal-fired power plants.

According to Doosan Heavy Industries & Construction, if the currently developing EME is additionally installed on existing environmental facilities, fine dust and ultrafine dust generated from thermal power plants can be reduced to 0.5mg/Nm3 or less, about 4% of the Ministry of Environment’s permissible standard. This is one-tenth of the world’s strictest emission standard of 5mg/Nm3. It is said that installing EME in all domestic coal-fired power plants could reduce fine dust by 37,000 tons annually.