Waste plastic to oil? Really! With the blessing of this space technology
Plastic, as an important basic material, can be seen everywhere in daily life. The essence of plastic pollution is that plastic waste enters the natural environment such as soil and water and is difficult to degrade, which brings visual pollution, soil damage, microplastics and other environmental hazards.
In the treatment of waste plastics, in addition to the well-known physical recovery, there are chemical recovery, mainly using pyrolysis, depolymerization and other methods. So space pyrolysis SHCP technology, this military technology to civilian projects, what kind of advantages? How will play a role? In the future, the chemical recycling of waste plastics will be in what direction?
The reporter interviewed Zhang Yanjun, deputy director and researcher of Beijing Aerospace Power Research Institute and main inventor of SHCP technology.
Chemical recycling of waste plastics is at the right time.
"China's waste plastic chemical recycling has just started." Zhang Yanjun said.
In April 2021, the Ministry of Ecology and Environment organized the compilation of the "Technical Specifications for Waste Plastic Pollution Control (Draft for Comment)", which was reviewed and approved in principle in April this year. It is pointed out that the chemical regeneration of waste plastics refers to the method of using chemical technology to convert waste plastics into resin monomers, oligomers, pyrolysis oil or synthesis gas, which is suitable for dealing with waste plastics with low value, complex composition and difficult physical regeneration.
In July 2021, the National Development and Reform Commission issued the "14th Five-Year Plan for the Development of Circular Economy", proposing that by 2025, the waste material recycling network will be more complete, the recycling capacity of renewable resources will be further improved, and a resource recycling system covering the whole society will be basically completed.
In September 2021, the National Development and Reform Commission and the Ministry of Ecology and Environment issued the "14th Five-Year Plan of Action for Plastic Pollution Control". One of the main tasks is to accelerate the standardized recycling and disposal of plastic waste, including strengthening the standardized recycling and disposal of plastic waste. Clear and transport, establish and improve the collection, transportation and disposal system of rural plastic waste, increase the recycling of plastic waste, and improve the level of harmless disposal of plastic waste.
In November 2021, the Ministry of Industry and Information Technology issued the "14th Five-Year" Industrial Green Development Plan, which mentioned the implementation of plastic pollution control requirements, the implementation of the comprehensive utilization of waste plastics industry norms, to encourage the development of waste plastics chemical recycling. Promote the thermal cracking of low-value waste plastics.
Chemical Regeneration of Waste Plastics Advance in Dilemma
According to Zhang Yanjun, the chemical recycling of waste plastics can reduce fossil energy consumption, realize the recycling of waste plastics at the same level, and have a significant carbon reduction effect. "But there are no successful commercial application cases."
Where exactly is the sticking point?
The industry chain is still facing difficulties. "In the National Economic Industry Classification, there is no accurate classification of waste plastic chemical recycling industry, and there is no clear positioning and supervision. Some regional governments require projects to land in very scarce chemical parks or chemical gathering areas. At the same time, the chemical recycling technology of waste plastics is uneven and easy to be confused with" local refining ", which makes it difficult to land such projects." Zhang Yanjun said.
In addition, there are difficulties in the raw material end, production end, product end and customs clearance.
It is difficult to collect raw materials-at present, most of the low-value waste plastics mainly flow to landfills and incineration plants, which are geographically dispersed.
Production is difficult to develop on a large scale-first, the technology is not mature. Taking pyrolysis technology as an example, whether it is intermittent operation equipment, or continuous external heat pipe type and rotary equipment, there are problems of slow heat transfer speed and uneven heat transfer, resulting in small equipment processing scale, serious coking, and poor adaptation to raw materials. Two is the absence of technical specifications. Technical routes, energy consumption and other aspects can only learn from incineration power generation or chemical industry standards, design and construction costs are high. Third, the technical bottleneck needs to be broken. Low-quality waste plastics have complex components, high pollution, and high content of impurities such as Cl and Si in plastic pyrolysis oil, which cannot be directly processed in refineries.
End products still need to "break through"-for example, the "Technical Specification for Pollution Control of Waste Plastics" (draft for comments) mentions that unprocessed pyrolysis oil and processed products that do not meet relevant product quality standards should be managed in accordance with hazardous waste. In view of the lack of waste plastic pyrolysis oil standards, the product needs to be processed to meet the relevant fuel oil standards, which increases the production cost.
However, if we want to successfully enter the downstream refinery production process to make new plastics, we still need to solve the problem of removing impurities and improving the quality of waste plastic pyrolysis oil.
Even after a return to hematopoiesis, the end product recycled plastics (PCR) will not be able to make great strides forward due to the lack of clear regulations on the field of use, proportion, etc. and the encouragement of relevant fiscal and tax policies.