Chemobiological process overcomes disadvantages of waste plastic pyrolysis

A joint research team has developed a technology to produce high value-added plastic raw materials called dicarboxylic acids (α,ω-diacids) by recycling mixed waste plastics. Work It was published inside Cleaner Production Magazine.

The team was led by Dr. from the Korea Energy Research Institute (KIER) Bioenergy and Resources Upcycling Research Laboratory. Sang-Goo Jeon and Dr. from the BioProcess Engineering Center of the Korea Bioscience and Biotechnology Research Institute. It was directed by Jung-Oh Ahn. (KRIBB)

Plastics are produced fossil fuels like oil and natural gasWaste plastics are recycled by being shredded, melted and produced into new products. However, wastewater and harmful substances are released during the production and processing stages, causing serious environmental impacts.

To solve these problems, many countries and companies are trying to establish a plastic circular economy. Especially recently, technologies that enable the recycling of plastics in an environmentally friendly way through chemical methods such as pyrolysis have attracted attention.

However, the pyrolysis method is not a perfect solution. This is because only 30% of the naphtha component in the pyrolysis oil produced during pyrolysis is recycled as plastic raw material, while the majority is used as low-quality fuel that emits greenhouse gases during combustion.

The Korean research team proposed a chemo-biological process combining chemical and biological methods to overcome the limitations of traditional chemical recycling techniques. Instead of using pyrolysis oil as a low-quality fuel, the developed process converts it into normal paraffins that serve as raw materials for microbial reactions and uses them as raw materials for microorganisms to produce plastic raw materials.

Using chemical pretreatment technology Selective purification of only normal paraffins from pyrolysis oil developed by the Korea Energy Research Institute (KIER) is possible. When the pyrolysis oil reacts with a catalyst in a high-temperature environment filled with hydrogen at 400°C, impurities and toxic substances are removed and converted into normal paraffins.

After being used as food for microorganisms, purified normal paraffins are converted into dicarboxylic acids, which are ultimately high value-added plastic raw materials used in products such as polyester (PES), polyamide (PA) and polyurethane (PU).

The research team predicted that using this technology could reduce the production cost of plastic raw materials by up to 40% compared to existing petrochemical-based production technologies. In addition, 30% of the pyrolysis oil used as low-quality fuel is converted into plastic raw materials, offering advantages for national greenhouse gas reduction.

Dr. Jeon stated: “This technology overcomes the limitations of existing chemical plastic recycling methods and provides a plastic Achieving circular economy and carbon neutrality. “We are currently carrying out validation procedures for synthesizing plastics using produced dicarboxylic acids and plan to continue technology transfer and commercialization in collaboration with interested companies.”