【Frontiers in HaiChuan Chemical Technology】New technologies for complete combustion and neutralization of toxic gases, enabling the harmless treatment of polyethylene waste

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MOSCOW, August 23 — Researchers from the Kabardino-Balkarian State University and other institutions recently reported that their team is making progress in developing a new technology for rendering polyethylene waste harmless by ensuring its complete combustion and neutralization of toxic gases. Polyethylene is a widely used plastic with high stability and is difficult to degrade naturally. The team wrote in a journal of the Ibragimov Comprehensive Scientific Research Institute of the Russian Academy of Sciences that currently used treatment methods such as burning release carbon monoxide, nitrogen monoxide, and other harmful substances due to incomplete combustion. The researchers ground the discarded polyethylene into powder and mixed it together in proportion with an eutectic mixture of lithium nitrate, sodium nitrate, and potassium nitrate, as well as a base. An eutectic mixture is a mixture formed by two or more substances in specific proportions, resulting in a relatively lowest melting point. The researchers placed the well-stirred mixture mentioned above in an oven and heated it to 220 degrees Celsius. During this process, all the components melt; the nitrate eutectic mixture begins to decompose, releasing oxygen atoms that are more active than under normal conditions, which causes the molten polyethylene to oxidize and burn completely. When the temperature inside the oven is gradually raised to 500 degrees Celsius and maintained for 20 minutes, polyethylene undergoes oxidation; toxic gases such as carbon monoxide, nitrogen oxides, and sulfur oxides generated during combustion accumulate in the alkaline melt, where they are then neutralized through redox reactions to form harmless salt substances. During the experiment, air tests in the laboratory revealed no toxic gases exceeding the permitted concentration levels. Furthermore, in this experiment, when the temperature inside the oven rose to 450 degrees Celsius, intense chemical reactions produced flames that reached up to 3 meters high, indicating the release of enormous amounts of energy. Researchers believe that the mixed melt used in the experiment could potentially be developed into solid fuels for rocket engines and metallurgical processes in the future. In the next phase, researchers will use specialized equipment to conduct more in-depth quantitative calculations.