Plastic cycle to promote the development of green transformation
Fu Xiangsheng, Vice Chairman, China Petroleum and Chemical Industry Federation
Since the birth of plastics, they have made important contributions to the progress of human civilization, especially in the replacement of steel and wood, energy conservation and emission reduction. But today, tackling plastic pollution has become a global consensus. Plastic recycling economy is an important measure to reduce plastic environmental pollution.
Plastic recycling economy is divided into physical cycle and chemical cycle. Physical recycling is a practical way to recycle waste plastics. Chemical recycling can realize the high-value reuse of waste plastics, and many enterprises at home and abroad have achieved important stage results.
Some use depolymerization or decomposition methods to reduce waste plastics to monomers and polymerize again to achieve chemical cycling. It is understood that the earliest DuPont and Huntsman in recent years have mastered the "methanol decomposition technology" to decompose waste polyester (PET) beverage bottles into methyl terephthalate and ethylene glycol monomer, and then re-synthesize a new PET resin to achieve a closed-loop chemical cycle.
There are also gasification of waste plastics into syngas or pyrolysis into oil, and then synthesis of chemicals and polymers. For example, BASF is developing the thermal cracking process, the waste plastic thermal cracking into syngas or oil products, with this raw material in the Ludwigshafen integrated site to produce various chemicals or polymers, its quality up to food grade; Eastman achieves chemical recycling of a range of polyester plastic waste through polyester recycling technology, which can reduce greenhouse gas emissions by 20% to 30% compared to traditional processes. Japan Kobelco Environment uses a fluidized bed gasifier to gasify low-purity, non-recyclable waste plastics and use the obtained syngas to produce methanol, the project plans to start operation in September 2023, this method can comprehensively reduce 100,000 tons of carbon dioxide emissions for every 60,000 tons of waste plastics treated. The Chinese Academy of Petrochemical Sciences, aerospace science and industry and other enterprises have also achieved phased results in plastic recycling.
The chemical cycle is not a problem from a technical point of view, because chemical reactions are mostly reversible: they can be decomposed if they can be synthesized, and depolymerized if they can be aggregated. The biggest obstacle at the moment is economic. It's cost and price. Therefore, technical solutions alone are not enough; they also require policy impetus, as well as consensus and global action.
Accelerate the application and promotion of chemical recycling technology
Li Mingfeng, president of Research Institute of Petrochemical Science, Sinopec
Chemical recycling of waste plastics is recognized at home and abroad as a low-carbon, clean and the only recycling method that can achieve sustainable development. In recent years, international chemical giants have accelerated the layout in the field of plastic recycling, LG, Saudi Basic Industries Company, bp and other international well-known enterprises have carried out plastic recycling research. Among them, chemical recycling is the most important. Because chemical recycling is suitable for mixed waste plastics with high impurity content and cannot be physically recycled, it is considered by the industry as the future direction of technology development. Only 12% of China's waste plastics are currently recycled by physical methods, and there is almost no chemical law, so there is still huge room for development.
The promotion of chemical recycling cannot be separated from the support of technology, and the waste plastic pyrolysis technology is the key core technology used by almost all enterprises. However, the development of waste plastic pyrolysis technology is very difficult, because there are more than 200 types of plastic raw materials involved, both general plastics, special plastics, and engineering plastics, making the technical needs of various refining enterprises very complex. At present, although the chemical recycling technology of waste plastics in China has achieved rapid development, the overall is still in the stage of small to pilot or industrial demonstration expansion. Rapid technological breakthroughs require greater efforts in technology research and development and broader cooperation.
In 2021, led by the Academy of Stone Sciences, 11 units including Engineering Construction Company, Yanshan Petrochemical, Yangzi Petrochemical, Maoming Petrochemical, Chinese Academy of Environmental Sciences, Beijing Institute of Petrochemical Technology, Tongji University, and Zhejiang Provincial Governor Triangle Circular Economy Technology Research Institute applied for the Petrochemical Federation's "Industrial Technology Innovation Center for Waste Plastics Chemical Recycling Industry" and successfully won the award. In the next step, the Academy will rely on the center to carry out industry-university-research collaborative innovation, and strive to build a research and development platform for high-value utilization technology of waste plastics applicable to different types of plastics and different sources, develop directional conversion technology of waste plastics, and carry out development and industrial application research of new chemical recycling processes of waste plastics and different technology combinations, so that the chemical recycling technology of waste plastics can reach the international leading level.
Let waste plastic be recycled
Guo Zifang, vice president of SINOPEC Beijing Chemical Research Institute
In order to help achieve the goal of "double carbon", we have been working hard to "collect and use" and deeply cultivate the field of polymer recycling.
"Back", most of the packaging plastics on the market are multi-layer, these plastics are not only polyolefin, different components to recycling increased a lot of difficulty, to achieve "back", a very important step is to choose a single raw material to produce plastic packaging, BOPE (bidirectional stretching polyethylene) is a representative, This single-material packaging structure is more conducive to plastic recycling than the traditional packaging structure of a variety of different materials.
In terms of "use", physical recycling and chemical recycling are the two main ways of recycling waste plastics, and we always adhere to walking on two legs and developing a variety of technical routes to ensure that recycled materials can be used. In terms of physical recycling, for the continuous processing and reuse of recycled plastic film, automotive plastic secondary recycling technology and other fields, we cooperated with well-known domestic universities and enterprises to tackle key problems and achieved initial results. In the field of chemical recycling, we have independently developed microwave plasma cracking technology, using waste polymers as cracking raw materials, triene yield is equivalent to the traditional naphtha steam cracking process, and accelerate the research and development in the field of catalytic cracking, and strive to achieve a variety of waste plastics efficient chemical recycling. We have also developed a multi-phase solvent, which is introduced into recycled plastics, which can improve the bonding ability between a variety of polymers to form a higher performance and more stable material, which is expected to achieve non-degraded reuse of hybrid plastics, and can be applied to household appliances, construction, transportation and other fields.
The recycling of waste polymers is an important part of the polymer industry in the establishment of a sound green low-carbon circular development economic system. In the future, the Institute will continue to focus on the development, application, recovery and recycling of new materials, and is committed to improving the efficiency and quality of physical recycling, promoting the research and development and industrialization of new chemical recycling technologies, helping to build a new model of plastic circular economy, and thus creating a closed-loop industrial chain of green economy.
