By Kim Seung-yeon
ULSAN, Sept. 17 (Yonhap) -- The process of recycling plastics is most widely known to be about breaking used plastics into little pieces, washing, sorting and drying them before turning what's left of them into new plastics.
Chemical recycling, the more sophisticated method, involves extracting raw materials from used plastics or significantly changing the chemical structure of the waste; hence, there is no need to sort by color or condition of contamination.
South Korea's SK Group, the second-largest conglomerate in the country by assets, which has major oil refinery and petrochemical units under its wing, is at the vanguard of chemical recycling as it steps up the drive for a green energy transition toward decarbonization.
In its main refinery and chemical plant in Ulsan, an industrial city on the southeast coast, SK is building what will be the world's first plastic recycling cluster with core chemical recycling facilities.
The Advanced Recycling Cluster (ARC) will be built on 215,000 square meters of land -- a size equivalent to 22 football stadiums -- inside the 8.3-million-square-meter Ulsan CLX.
The 1.8 trillion-won (US$1.35 billion) project is scheduled to break ground next month, aiming to begin operations in 2025.
"Some 320,000 tons of plastic waste -- which is 213 million 500-milliliter PET bottles of water -- will be recycled every year once the ARC is operational," said Kim Ki-hyeon, an official at SK Geocentric Co., the chemical unit in charge of the ARC, during a press tour in Ulsan on Wednesday.
The recycling cluster will house three major chemical recycling facilities: high-purity polypropylene (PP) extraction, depolymerization of PET plastics or polyester, and pyrolysis.
Depolymerization chemically turns plastic and fiber waste into the original form of monomers and enables recycling without quality degradation. SK is working with Canada's Loop Industries on the depolymerization technology.
For PP extraction, SK is collaborating with U.S. Purecycle Technologies, which specializes in extracting ultra-pure PP resin.
SK has a license contract with British recycling company Plastic Energy for pyrolysis, a technology that converts plastic waste into crude oil through high-temperature heating with limited oxygen. Plastic items, such as baby bottles and interior materials for vehicles, are made using crude oil.
SK Innovation Co., SK's energy unit, plans to use the pyrolysis oil as feedstock for its naphtha cracking by refining it using the post-pyrolysis processing it has developed.
"Since it is chemical recycling, it has the advantage of being able to produce recycled PET in almost a virgin form, so there is no need for mixing or blending to enhance the product without any quality deterioration," Park Ji-hoon, an SK Geocentric engineer, said.
These chemical recycling processes will eventually help create a "circular economy" that turns waste into resources and offers a solution to problems associated with landfills and other waste disposals, SK said.
Starting in 2026, dumping waste at metropolitan landfill sites will be banned in South Korea. A ban on burying household waste in the ground will go into effect in 2030, and all waste from residential areas must be recycled or incinerated.
"We believe that recycling plastic waste that was supposed to be incinerated certainly contributes to a reduction in carbon emissions," Kim said.
SK said it is doing its own calculations on the carbon emission effects of chemical recycling, but it can reduce carbon emissions by more than 60 percent compared with incineration, citing the results of research by global chemical firm BASF.
SK Group Chairman Chey Tae-won, one of the most active business tycoons in the green transformation, said earlier that SK will aim to cut carbon emissions by 200 million tons, or 1 percent of the global target set by the International Energy Agency.
"This is the beginning of SK moving away from its oil-oriented business structure that once symbolized the country's rapid industrialization and presenting a model for future growth," an SK official said.