176
6 Waste Plastics Management and Conversion into Liquid …
6.6 Economic and Environmental Benefits of Waste Plastics
Management
Landfilling has been the most common method for disposal of waste plastics in the
past few years due to the low cost of construction and operation. So far around 4900
Mt of plastics, which is 60% of all plastics ever produced, has been disposed of
in landfills or discarded in the environment. The plastics are non-biodegradable or
slowly degradable and the natural degradation of plastics takes a very long time. As an
example, the mass of LDPE decreases by only 0.2% after 10 years of biodegradation.
This could result in taking up the landfill sites for a long time. It also hinders the
infiltration of surface water and contaminates the soil and water by the degradation
products of the plastics such as microplastics and plasticizers [4, 26]. Incineration
is another simple and low-cost method for disposal of waste plastics. However, it
results in the release of toxic substances such as dioxins, CO 2 , CH 4 , N 2 O, NO X and
SO X to the atmosphere. It also leads to emissions of chemicals and heavy metal
elements into air and water [4, 26].
A proper waste plastics management (recycling and conversion to liquid fuels
or carbon materials) can divert the waste plastics disposed of by landfilling and
incineration, hence reducing the amount of harmful chemicals and emissions going
to the air, water and soil. It can also preserve the life of aquatic animals that are
suffocated by ingesting waste plastics, and reduce the need for extraction of virgin
materials and consumption of fossil fuels for plastics production, leading to conservation of natural resources [4]. Plastics recycling involves the reforming, regeneration
or modification of waste plastics into new products. The recycling process usually
includes the material collection, identification, sorting, separating, size reduction,
extruding/compounding and pelletization. However, recycled plastics usually have
lower economic value compared with virgin plastics due to contamination and impurities. Moreover, a large portion of plastics have poor quality and are unable to
be reused. Thus, recycling cannot be considered as the ultimate disposal path for
the waste plastics, but adds more life-time to the plastics [4, 26]. Instead, thermal
cracking/pyrolysis, catalytic cracking or de-polymerization are more promising
waste plastics management solutions as they convert the waste plastics into highvalue products such as liquid fuels and carbon materials (carbon nanomaterials,
carbon fibers, activated carbon, etc.) [26].
References
1. Miandad R et al (2019) Catalytic pyrolysis of plastic waste: moving toward pyrolysis based
biorefineries. Front Energy Res 7:1–17
2. Plastics – The facts 2018: an analysis of european plastics production, demand and waste data.
pp. 1–60 (2018)
3. Zhang H (ed) (2011) Building plastic. In: Building materials in civil engineering, pp 289–423
6 Waste Plastics Management and Conversion into Liquid …
6.6 Economic and Environmental Benefits of Waste Plastics
Management
Landfilling has been the most common method for disposal of waste plastics in the
past few years due to the low cost of construction and operation. So far around 4900
Mt of plastics, which is 60% of all plastics ever produced, has been disposed of
in landfills or discarded in the environment. The plastics are non-biodegradable or
slowly degradable and the natural degradation of plastics takes a very long time. As an
example, the mass of LDPE decreases by only 0.2% after 10 years of biodegradation.
This could result in taking up the landfill sites for a long time. It also hinders the
infiltration of surface water and contaminates the soil and water by the degradation
products of the plastics such as microplastics and plasticizers [4, 26]. Incineration
is another simple and low-cost method for disposal of waste plastics. However, it
results in the release of toxic substances such as dioxins, CO 2 , CH 4 , N 2 O, NO X and
SO X to the atmosphere. It also leads to emissions of chemicals and heavy metal
elements into air and water [4, 26].
A proper waste plastics management (recycling and conversion to liquid fuels
or carbon materials) can divert the waste plastics disposed of by landfilling and
incineration, hence reducing the amount of harmful chemicals and emissions going
to the air, water and soil. It can also preserve the life of aquatic animals that are
suffocated by ingesting waste plastics, and reduce the need for extraction of virgin
materials and consumption of fossil fuels for plastics production, leading to conservation of natural resources [4]. Plastics recycling involves the reforming, regeneration
or modification of waste plastics into new products. The recycling process usually
includes the material collection, identification, sorting, separating, size reduction,
extruding/compounding and pelletization. However, recycled plastics usually have
lower economic value compared with virgin plastics due to contamination and impurities. Moreover, a large portion of plastics have poor quality and are unable to
be reused. Thus, recycling cannot be considered as the ultimate disposal path for
the waste plastics, but adds more life-time to the plastics [4, 26]. Instead, thermal
cracking/pyrolysis, catalytic cracking or de-polymerization are more promising
waste plastics management solutions as they convert the waste plastics into highvalue products such as liquid fuels and carbon materials (carbon nanomaterials,
carbon fibers, activated carbon, etc.) [26].
References
1. Miandad R et al (2019) Catalytic pyrolysis of plastic waste: moving toward pyrolysis based
biorefineries. Front Energy Res 7:1–17
2. Plastics – The facts 2018: an analysis of european plastics production, demand and waste data.
pp. 1–60 (2018)
3. Zhang H (ed) (2011) Building plastic. In: Building materials in civil engineering, pp 289–423