PLASTIC RECYCLING: Material and Energy Recovery
Often, when we think about plastic, we associate the word to the concept of “pollution”, but if we think about it better, every kind of waste can become cause of pollution, if not properly recovered.
In reality, plastic is a material that can be recycled and its recycling allows for the creation of new products and new profits.
The complete list of the different types of plastics and the different types of polymers is available on the Consorzio Recupero Plastica website and the Corepla Consortium provides a list of the main packaging polymers with the relative codes. Codes are important because they also serve to differentiate the material for recycling. PVC, PET, PP, HDPE, etc. are some acronyms of plastic packaging, now in use, which refer to the most frequently recycled polymers in dedicated plants.
But which recycling process can plastic undergo? Recycling can be mechanical, chemical or energy recovery. Let’s see the differences.
THE MECHANICAL RECYCLING
With the mechanical recycling, plastics once again become a secondary material for new products. The plastic material is volumetrically reduced, differentiated by polymer, washed, melted and “regranulated”. The technologies for the treatment and selection are very important for the correct recovery of the different types of polymers. The technologies related to optical selection are able to divide the different polymers through the use of intelligent software programmes that recognize the materials of which the different flakes are made of for a timely selection.
Obtaining an increasingly pure selection is essential not only to ensure greater earnings, but also to get closer to the recycling targets set by the European Union.
CAMEC Plant for the plastic recycling composed by shredder GRR280 + Conveyor Belt + Mill MG300
The advantages of the mechanic recycling
All thermoplastic products can be mechanically recycled, greatly reducing the use of virgin material for the production of new products and requiring less use of the energy needed for processing compared to the production of plastic from virgin material.
Among the mechanically recyclable plastic polymers we find EPS (Expanded Sintered Polystyrene), more commonly known as polystyrene, a versatile material that lends itself to the creation of countless products, and for various applications, but above all 100% recyclable and reusable indefinitely.
Rigid polyolefins HDPE and PP are also the most recycled. They are used in a wide range of applications for food, home and personal care products. The largest market for recycled HDPE is building and construction while for recycled PP the automotive one.
Not all plastics are easily mechanically recycled or have an outlet market. For this reason, plants for the chemical recycling of plastics have been created in recent years. In chemical recycling the polymer is decomposed. On the website of the IPPR institute, Institute for the Promotion of Recycled Plastics, chemical recycling is well described in the various processes: pyrolysis, hydrogenation, gasification, chemolysis, glycolysis.
THE ENERGY RECOVERY OF PLASTICS
All plastics that cannot be mechanically or chemically recycled are destined for energy recovery through waste-to-energy or burned in cement factories for energy production.