[Report] 'Water Treatment Magic' Through a 2mm Diameter Separator Membrane

Visiting Lotte Chemical Daegu Water Treatment Plant
Filtering Impurities with Micro Pores
The Principle of Purifying External Water

Kim Dong-hyun, Senior Manager of the Water Treatment Production Team at Lotte Chemical, is explaining about the membrane. Photo by Lotte Chemical

[Asia Economy Reporter Choi Dae-yeol] The water industry has traditionally been led by advanced countries such as the United States, the United Kingdom, and France in terms of technology and market development. This is thanks to early recognition of its importance, with companies honing their technological capabilities and governments and international financial institutions firmly establishing public-private partnership systems. Especially as industrial structures have advanced, the global use of industrial and manufacturing water has increased, making water treatment facility demand grow rapidly due to the heightened importance of managing this water.

At the Lotte Chemical water treatment membrane factory recently visited, equipment was running nonstop to produce filters as thin as a slender straw. The hollow fiber membranes, about 2 mm in diameter with a hollow center, are made by coating a solvent mixed with fluoropolymer (PVDF) materials onto commonly seen PET reinforcement materials. Through this process, thin films form on the membrane surface with air pores (pores) sized tens to hundreds of nanometers. The pores of the membranes produced by Lotte Chemical are about 0.03 μm, roughly one-thousandth the thickness of a human hair.

The membrane fibers produced this way are cut into 2 to 3 meter units and about 1,800 pieces are connected to form a single module. At the frontline sites, multiple modules are linked together in a cassette form for supply. When the inside of the membrane is made into a vacuum state, external water is filtered and purified as it passes through.

Kim Dong-hyun, head of Lotte Chemical’s water treatment production team, said, "Maintaining uniform pore size is crucial, as well as the coating process and the ratio of materials mixed into the solvent. Considering that wastewater treatment membranes typically last more than five years, the durability of the finished product is also important."

Sheet-type hollow fiber membrane. About 1,800 membrane fibers are bundled into one module, and multiple modules are assembled into a cassette-type installation. Photo by Lotte Chemical

Expected Orders of 240,000 Tons This Year... More Than Fivefold Growth Compared to Last Year
Water and Wastewater Volumes to be Reduced to Half of 2019 Levels by 2030

The factory, which began operations in 2018, has been busier than ever recently. Lotte Chemical expects its order volume this year to reach 240,000 tons (based on the amount of water that can be purified daily). This is enough to filter water used daily by 800,000 people. Considering last year’s order volume was about 45,000 tons, this represents more than a fivefold increase.

Key industries in Korea’s economy such as semiconductors (Samsung Electronics, SK Hynix), refining and petrochemicals, and steel use large amounts of industrial water, and environmental regulations have heightened interest in wastewater treatment. Lotte Chemical aims to reduce its own water usage and treat and process used water to a reusable level, targeting a reduction of water and wastewater volumes to half of 2019 levels by 2030.

The increase in companies seeking membranes made by Lotte Chemical is due not only to water purification technology but also to reduced operational costs. Water treatment facilities require periodic air injection to remove filtered sludge and impurities, but Lotte Chemical’s independently developed technology and design have cut the required air volume by about half.

Lotte Chemical began R&D on water treatment membrane technology in 2011, recognizing the growing need for water resource management due to water scarcity and climate crises, and the significant growth potential ahead. According to the UK research institute Global Water Intelligence, the global water treatment market was estimated at $834.1 billion last year and is expected to grow at an average annual rate of over 4%. Lotte Chemical officially entered the market in 2015 by acquiring Samsung SDI’s water treatment business technology, and the Daegu plant, completed and operational since 2018, is considered the largest water treatment membrane factory in Korea.

Lee Young-jun, head of Lotte Chemical’s Advanced Materials Business, said, "We will do our best to expand overseas markets by establishing strategic partnerships with leading domestic and international water treatment companies. Based on our technological capabilities, we will contribute to efficient water resource management, realize social value, and achieve high value-added creation."

Lotte Chemical Water Treatment Plant in the Daegu Water Industry Cluster. Photo by Lotte Chemical