Solutions and Technologies to Recycling Plastics

This article discusses the latest solutions and technologies for recycling, up-cycling, and biodegrading of plastics. It covers the sources of plastic waste, processing of reclaimed plastics, primary and mechanical recycling, chemical or feedstock recycling, hydrolysis, and more.

Solutions and technologies to recycling plastics 1
SOLUTIONS AND TECHNOLOGIES TO RECYCLING, UP-CYCLING, AND
BIODEGRADING OF PLASTICS
Name of Student
Institution Affiliation
Solutions and technologies to recycling, up-cycling and biodegrading of plastics

Solutions and technologies to recycling plastics 2
Introduction
In the past years, the use of plastics has been increasing at a very high rate over many parts of the
world. Most countries have been using rare varieties of petroleum products in manufacturing a
wide range of products for different uses. Most of the plastic products do not even last for a year,
and large quantities of these products are gotten rid of. The recovery of plastic waste is in most
cases not economical for the concerned organizations. Many companies have invented new
technologies and come up with effective programs to enhance the reprocessing of plastic waste
for both economic benefits and the benefits of the surroundings (Niaounakis, 2013). Plastics are
made from unrecoverable materials, and the decomposition rate of the waste plastic is very slow.
The plastic waste is the most unpleasant junk people can have around and have to keep seeing it
for a long period since it does not decompose easily.
Sources of waste products
The main source of plastic junk is the large industry activities such as processing manufacturing
and packaging. The scrap has desirable features and can be recovered for the other uses. The
plastic waste is usually in low amounts but keep in increasing with the increase in their demand.
Plastic waste from commercial settings such as the business units like wholesalers the retail
shops and crafts work. The plastic junk from these sources is usually polluted (Embalagens,
2014).

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The agricultural waste can be recovered from farms found within the urban settings. The
agricultural plastic waste is usually in the form of pipes from irrigation activities and plastics
used in packaging seeds and fertilizer. (Harbers, 2014)
The municipal sources of waste plastics refer to the plastic waste obtained from domestic
activities within residential areas. The concerned individuals can collect the plastic litter from the
residential path or even agree with the residents to collect from their homesteads.
Processing of reclaimed plastics
The technology and procedures used by small enterprises in recycling plastic waste.
Primary improvement, after the collection of the plastic they are cleaned and classified. The
strategy used in the washing is usually determined available plastic waste. In the small
operations, hand washing is used while in large operations the washing and sorting can be done
by use of machines (Atala, 2012).
 Strategies for cutting the plastics into required sizes. There are various purposes of
reducing the plastic sizes such as, coming up with a product that can be efficiently
processed and for the storage and movement reasons. The achievement of the required
dimensions is achieved at by use of several methods.
.The large objects are then cut into required sizes by use of simple cutting objects
such as scissors and other sharp objects.

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.A typical shredder is used for the small pieces. The shredder has several blades and
is operated by an electric motor. The shredding results into the uneven portions of plastics which
can be processed further.
.The agglomeration process involves heating and exposing the heated content under
low temperatures within a single machine to plastic grains usually named crumbs.
Primary recycling
This is the mostly used technology in the recycling of plastics it is mainly represented by their
low cost and their simplicity. This technique refers the reuse of the products in their original
structures. The key disadvantage of this method is that the number of each cycle of plastics is
limited. (Al-Salem, 2015).
Mechanical recycling
This method involves the collection of the waste plastics and then remolding them into the final
new product. This technique does not involve the alteration of the practice during
remolding .The technique is usually represented by a physical technique , via which the waste
plastics will be formed by washing, shredding or cutting into the granules, flakes or pellets of
the correct quality for the purpose of manufacturing and after that the plastics are remolds
through melting to be processed new products through the process of extrusion. The plastics
can be reprocessed and be blended with other new materials to obtain an outcome which is more
superior. After the plastics are cleaned, dried and sorted they are processed into the new
products. At the same time, the quantity of the waste plastics will greatly reduce .The main
disadvantage of this technology is the heterogeneity of the plastics which occurs as a result of

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The low molecular weight of the recycled plastics. It occurs due to the chain-scission reaction
caused by the presence of traces of acidic impurities and water. In order to the chances of
occurrences of this reaction drying of the waste plastics is highly recommended. The figure
below illustrates the steps involved in mechanical recycling.
Fig 1: Steps involved in mechanical recycling
Chemical or feedstock recycling
This technology is defined as a process through which the plastics are chemical to monomers or
partially depolymerized to the oligomers through a chemical reaction. The formed monomers can
be applied for the new polymerization to reproduce the original or related plastic product. This
technology can transform the plastic material into the smaller molecules which are suitable for

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the application as feedstock material starting with the monomers, oligomers or a mix of any other
hydrocarbon compounds (Golinska, 2013).
The chemical reactions which are used to convert the plastics into the monomers are:
 Hydrogenation
 Gasification
 Degradation in a microwave reactor
 Pyrolysis
 Catalytic cracking
 Thermal cracking
 Photodegrading
 Mentanolysis
 Ultrasound degradation
 Chemical depolymerization
The technology of chemical recycling is not well developed and because of that not many
companies have adopted this technology because this technology requires intense investments
and trained workforce which is very expensive to acquire. Currently, many technologies are
under investigation such as, pyrolysis and gasification to establish their suitability and the
process which have reached commercial maturity currently are Mentanolysis and glycolysis
(Grunwald, 2014).
Hydrolysis

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This is a reutilizing technology which includes a reaction of plastic with water in an acid, natural
or alkaline environment, resulting in total depolymerization into its monomers. The main
limitation of this technology are the high temperatures which are required, i.e., between 200 and
250oC and pressure of between 1.4 and 2 MPa and the long period which is required to complete
the depolymerization. This technology is not widely applied, due to its high cost.
Mentanolysis
The chemical recycling of plastic by Mentanolysis involves the plastic degradation by methanol
at temperatures ranging between 180 and 280oC and at a pressure ranging from 2 to 4 MPa with
the main products being terephthalate and the ethylene glycol. The optimal conditions refer to
the temperatures between 260 and 270-degree Celsius, and the pressure of 9.0 to 11.0MPa and
the weight ratio from 6 to 8. The moment the main products are obtained the dimethyl
terephthalate is purified by distillation to remove all the physical contaminants and then it can be
reused to produce plastics (Clark, 2016).
Glycolysis
The chemical salvaging of plastics by glycolysis involves the ethylene glycol insertion into the
plastic chains to give hydroxyethyl, which is a substrate for the plastic synthesis and other
oligomers. From the researches that have been carried out by other researches regarding the
recycling of plastics by use of this technology, many basic ionic liquids, and ionic liquids were
used as a catalyst.
Depolymerization of plastic wastes

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Great technological advancements have been achieved in the last few years on the
depolymerization of plastic wastes which have made it possible to convert one type of plastic
into another which is more valuable.
Thermal and the catalytic pyrolysis of plastic wastes to liquid fuel
In this technology of plastic pyrolysis, the macromolecular structures of polymers are crashed
into smaller oligomers molecules and at other times into monomeric units. Additional
dilapidation of these succeeding molecules relies on some different factors which include;
residence time, temperature and the presence of catalysts and other process conditions. The
pyrolysis reaction can be conducted with or without the presence of a catalyst. Accordingly, the
reaction will be thermal and catalytic pyrolysis. Since most of the plastics are a polyolefin, with
that a lot of research has been done in the past decade for the better outcome.
Energy recovery or the quaternary recycling
This method is a recovery technology of plastic energy .Incineration is the most effect method of
reducing the volume of the organic material that are involved in the recovery of energy content.
This technology is among the best solutions because it usually generates a lot of energy from the
waste plastics, at the same time it does not pollute the environment
References

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Al-Salem, S. (2015). Plastics to Energy: Fuel, Chemicals, and Sustainability Implications.
Chicago: Elsevier Science.
Atala, A. (2012). Synthetic Biodegradable Polymer Scaffolds. Sydney: Springer Science &
Business Media.
Clark, J. H. (2016). Feedstock Recycling of Plastic Wastes. London: Royal Society of Chemistry,
Embalagens, I. d. (2014). Better Packaging: Better World. Chicago: Instituto de Embalagens.
Golinska, P. (2013). Environmental Issues in Automotive Industry. Paris: Springer Science &
Business Media.
Grunwald, P. (2014). Industrial Biocatalysis. Texas: Pan Stanford.
Harbers, H. (2014). Inside the Politics of Technology: Agency and Normativity in the Co-
production of Technology and Society. London: Amsterdam University Press,
Niaounakis, M. (2013). Biopolymers: Reuse, Recycling, and Disposal. London: William
Andrew.