[Cement, Misunderstandings and Truths]②Conflicting Evaluations and Challenges of Cement

A panoramic view of Ssangyong C&E waste heat power plant. It recycles the high temperature of 1400 degrees generated from the kiln. Separate boilers are installed in the preheating chamber and cooler, which are the front and rear processes of the kiln, to recover the heat source emitted into the atmosphere, produce steam, and generate electricity by turning turbines. It is a globally recognized eco-friendly power generation facility that does not produce air pollutants.
[Photo by Ssangyong C&E]

[Asia Economy Reporter Kim Jong-hwa] Cement is made by mixing limestone, clay, silica, and iron oxide. These materials are crushed and mixed, then heated at high temperatures to produce an intermediate product called 'Clinker.' When gypsum is added in a certain ratio to this clinker, cement is formed.

Among waste materials, waste plastics, waste vinyl, and waste tires are recycled as fuel, while coal ash, sludge (such as sewage treatment sediment), and discarded metal manufacturing molds are recycled as raw materials. Using these 'alternative raw materials and fuels (circular resources)' during the calcination process results in lower emissions of air pollutants compared to using bituminous coal.

However, regardless of these facts, the term 'garbage cement' continues to be used critically in South Korea. The cement industry laments, "While overseas waste recycling is praised as 'green cement,' in Korea it is disparaged as 'garbage cement.'"

Recycling circular resources in the cement industry is a global trend. In the United States, Europe, Japan, and other regions, the use of cement kilns for recycling circular resources has expanded since the 1970s and 1980s to address waste problems. In Europe, this is highly regarded as 'green cement,' and in Japan as 'eco cement,' reflecting the meaning of recycling difficult-to-treat waste.

The recycling rate of circular resources in the domestic cement industry is about 23% of total fuel, which is only half of Europe's recycling rate (46%). It is far below Germany's 68%, where recycling is most active. Europe is actively utilizing the cement industry to solve waste disposal problems and reduce greenhouse gases, aiming to increase the recycling rate of circular resource fuels to 65% by 2035.

Despite the cement industry's claim of 'green cement,' there remains an uncomfortable perception domestically. Although the Supreme Court ruled that there is no causal relationship between cement and respiratory diseases among residents near cement plants, the residents continue to harbor suspicions.

Also, in the early stages of circular resource recycling, some civic groups spread distorted claims calling it 'garbage cement,' and the cement industry failed to respond adequately. Due to the management crisis caused by the International Monetary Fund (IMF) financial crisis, the cement industry was unable to sufficiently inform the general public about the safety and excellence of circular resource recycling.

Recently, voices have emerged pointing out errors in the emission standards for harmful substances from cement. The nitrogen oxide emission limit for cement plants is 270 ppm for facilities installed after January 2007, and 80 ppm for those installed after January 1, 2015. However, no facilities have been installed since 2015, so all cement plants nationwide are subject to the most lenient standard of 270 ppm.

This standard is much weaker than those of the glass industry (180 ppm), steel industry (170 ppm), and incineration industry (50 ppm). Calls to strengthen the nitrogen oxide emission limits for cement plants and to retroactively apply the current 80 ppm standard to all plants are gaining traction as a way to resolve fairness controversies.

The cement industry's dilemma lies here. For cement plants, installing Selective Catalytic Reduction (SCR) devices is difficult due to space constraints and lack of assurance regarding performance stability. The cement industry is currently conducting a demonstration project for SCR technology development and plans to apply it to plants as soon as possible.

Eric Weinberger, Head of Environmental Health at Geocycle, in a video call with the Korea Cement Association.
[Photo by Korea Cement Association]

Despite these conflicting evaluations of cement, there is little disagreement that the cement industry is an alternative solution to environmental problems. Recently, with the increase in combustible waste such as waste plastics due to COVID-19 and other factors, recycling circular resources is recognized as a key to carbon neutrality.

Hong Soo-yeol, director of the Resource Circulation Social Economy Research Institute, said, "In cases like the recent 'Uiseong Garbage Mountain,' the cement industry has been deployed as a savior to solve environmental problems," adding, "Using cement kilns for treatment is a better choice than simple incineration for waste plastic disposal."

Eric Weinberger, Head of Environmental Health at Geocycle, Europe's largest circular resource recycling company, said in a video call with the Korea Cement Association, "All cement plants across Europe have been using waste as circular resources for over 50 years without any harmful issues," and added, "It is unfortunate that there is controversy in Korea surrounding cement made by recycling circular resources."