The research team uses the "green power" generated by photovoltaic technology and wind power technology to upgrade the recycling of pet waste plastics, which not only produces high value-added industrial chemicals and fuels, but also realizes the resource conversion of greenhouse gas carbon dioxide.
Sunlight, wind and carbon dioxide, with these readily available materials in nature, can efficiently convert polyethylene terephthalate (PET) waste plastics such as mineral water bottles and disposable packaging into common formic acid resources and hydrogen fuel in industry. Recently, the environmental research team of shanghaijiaotonguniversity has made a number of achievements in the field of waste plastic recycling.
Pet waste plastics and carbon dioxide are "negative to positive"
Zhaoyixin, Professor of School of environmental science and engineering, shanghaijiaotonguniversity, and his research team used the "green power" generated by photovoltaic technology and wind power technology to upgrade the recycling of pet waste plastics, which not only produced high value-added industrial chemicals and fuels, but also realized the resource conversion of greenhouse gas carbon dioxide.
Pet can be seen everywhere in our life. Many of the common beverage bottles, TV covers, lampshades, etc. are made of PET plastic. If a large number of pet waste plastics can not be reasonably and effectively recycled, it will not only cause environmental pollution, but also a waste of carbon resources. In recent years, based on the improvement of "green power" capacity of photovoltaic technology and wind power technology, since 2021, zhaoyixin team has taken the lead in the research on "green power" catalytic reforming of pet waste plastics to produce formic acid and hydrogen.
"In the initial research, we used renewable 'green electricity' catalytic technology to convert pet into formic acid and hydrogen, reducing the energy consumption of hydrogen production by traditional electrolysis of water." Zhaoyixin said that recently, the team and Professor Martin of Peking University upgraded the recycling of pet. Through the "green electricity" catalytic oxidation of pet waste plastics and the reduction reaction of carbon dioxide, pet waste plastics can only be converted into formic acid, which not only increases the output efficiency of formic acid, but also promotes the resource conversion of greenhouse gas carbon dioxide. It is estimated that using the upgraded recycling strategy, each ton of recycled PET waste plastic can create an economic income of about 557 US dollars, showing a high commercial economic value.
Meanwhile, zhaoyixin also said that the research on "green electricity" catalytic upgrading and recycling of waste plastics has moved from laboratory to industrialization, It also needs to overcome a series of theoretical and technical difficulties: "In the process of recycling, certain catalysts need to be used. Low-cost and high-performance catalysts can save costs, reduce energy consumption and increase the yield of useful materials. Such catalyst materials need to be developed and studied urgently. In addition, in order to achieve large-scale industrial application, the development and research of technology and equipment is also the focus and difficulty of future research. Although facing many difficulties, this waste plastic conversion technology provides a basis for national development Environmental economy and building a low-carbon society provide an effective way for development, and still have broad application and development prospects. "
Low carbon hard core achievements turn waste plastics into "treasures"
At present, the scientific research team of the school of environmental science and engineering of Shanghai Jiaotong University has achieved a number of internationally leading results in the field of waste plastics.
Waste plastics can be broken into nano plastics and accumulated in the environment for a long time. Understanding the environmental behavior of nano scale plastic particles is the key to accurately assess the ecological health risks of waste plastics and low-carbon recycling. Qiu Hao, associate professor of shanghaijiaotonguniversity, combined with outdoor sampling and indoor simulation, identified the main control factors affecting the water environmental behavior of nano plastics, revealed the mechanism of protein crown regulating the stability of nano plastics colloids, and then put forward a new idea to promote the efficient recovery of nano plastics flocculation sedimentation by adding lysozyme in water treatment, and quantified the environmental health risk dependent on the size of plastic particles, It has promoted the construction of fine risk management and control of plastic waste and low-carbon recycling system.
Jinfangming, a professor of Shanghai Jiaotong University, has carried out research on the hydrothermal recycling of waste plastics around the environmental hazards, difficult harmless treatment and low resource utilization rate of waste plastics, and innovatively proposed the hydrothermal reduction of carbon dioxide by using waste plastics such as PVC and PVC as reductants, realizing the collaborative recycling of waste plastics and carbon dioxide. The team successfully dechlorinated 100% of PVC waste plastics and converted them into clean fuels. At the same time, the team also reduced carbon dioxide to high value-added organic formic acid. This technology has no catalyst and simple process, showing a good prospect for industrial application.
In addition, in view of the unsustainability and difficult degradation of fossil fuel based plastics, as well as the bottleneck of biodegradable plastics polylactic acid as raw materials, Jin Fangming's team took the lead in exploring the technology of hydrothermal conversion of biomass wastes to lactic acid in the early stage, and recently expanded the hydrothermal technology to photocatalysis and biomass raw materials to wet waste conversion. This research is actively cooperating with enterprises to promote industrial trial operation.