Kunststoffe international 10/2019 www.kunststoffe-international.com

51Plastics World Market K 2019

Polyethylene terephthalate (PET) for packaging applications still enjoy

stable growth rates. PET consumption (without fibers) doubled in the period from 2006 to 2016 from about 12 million t to 21 million t. For 2018, about 24 million t were forecast, and an increase to some 25 million t is expected for 2019 (source: Polyglobe). Growth is pushed mainly by the Asian markets, but a moderate increase is apparent also in Europe and North Ameri-ca. However, in the past two years there were no large new investments in polymer-ization plants for virgin PET nor any notable technical advancements. If fibers are in-cluded, worldwide production capacity

was about 33 million t in 2018. With 35 %, China has the largest production capac-ities, followed by the USA (11 %) and India (7 %) (source: Kunststoff Information). Fig-

ure 1 shows the production capacities of the five largest PET producers in 2017 (source: Statista). However, this graphic is not quite up to date, as the number 2 in the PET market – Mossi & Ghisolfi (M&G) in Tor-tona, Italy – had to file for bankruptcy.

Biopolymers and Renewable Raw Materials

Polyethylene furanoate (PEF) has been praised for years as a bio-based alternative

for PET. For this polymer, terephthalic acid was replaced with furandicarboxylic acid, which can be produced from renewable raw materials such as C6 sugars. But even after years, the highly praised biopolymer has failed to materialize. BASF has pulled out of the Synvina joint project with Avantium. The market introduction of PEF has been postponed to 2025. Meanwhile, Avantium has announced that they in-tend to commercialize PEF on their own.

And yet, PEF exhibits very positive polymer properties. That is probably the reason for the somewhat exaggerated ex-pectations that the industry had for the market introduction. With 86 to 88 °C,

Polyethylene Terephthalate (PET)

Prime Material for a Circular Economy

PET bottles can be recycled into new food packaging. Large-scale recovery systems and recycling procedures

have become established since many years. PET bottles made of 100 % post-consumer recyclate are already

available in the market, and a version made of renewable raw materials also exists. No other packaging plastic

can show such a positive balance. Nonetheless, PET is under criticism.

Bottles blow-molded from preforms are among the products that can be produced from recycled PET; about two thirds of PET recyclates are used to

produce films, secondary packaging such as strapping bands or substrates, as well as fibers, better known as fleece (© Erema)

»

© Carl Hanser Verlag, Munich Kunststoffe international 10/2019

52 SPECIAL K 2019 Plastics World Market

500,000 t per year are in operation, the present outlook is for a considerably smaller plant with a capacity of 5 to 10,000 t per year. When the problems with polymerization have been solved, and PEF comes onto the market, this packaging polymer will be able to reduce the dependency on fossil raw materials in the long term. PEF also scores in terms of recycling. Up to a certain degree, PEF can even make use of the established recyc-ling infrastructure for PET. A share of 2 % PEF in the recycling flow of PET is not seen as a problem. This simplifies the market introduction considerably. How-ever, if the share of PEF bottles becomes higher than 2 %, separate handling of the return flow must be considered.

PEF is 100 % bio-based if the second monomer ethylene glycol is also pro-duced with renewable raw materials. But bio-based ethylene glycol can also be used for PET. Regarding the “plant bottle” with a share of about 30 % renewable raw materials, however, things have become rather quiet in recent years. Similar to polylactic acid (PLA), PET’s other bio-based competitor. The market share of PLA beverage bottles is practically negli-gible and therefore not a serious com-petitor for PET. As an alternative for PET,

the glass transition temperature of PEF is slightly higher than for PET (69 to 74 °C). This indicates a lower diffusion and/or a better barrier. For example, the oxygen barrier of PEF is said to be six to ten times better than that of PET. Consequently, this would make PEF bottles suitable for oxygen-sensitive contents such as beer or juices without additional oxygen bar-riers or active oxygen scavengers. Also the barrier properties for carbon dioxide are higher by a factor of four to six, and two for water vapor than with traditional PET. On the other side, the processing temperature of about 235 °C is lower than for PET (265 °C). Compared with PET, this would reduce energy consumption during the production of PEF bottles. But PEF is not yet on the market, and the bar-rier properties were determined with pilot quantities. It remains to be seen whether the named and the anticipated more favorable properties of PEF com-pared with PET will come true. Even if everything works out well, PEF will not be able to challenge PET immediately in all fields in which the latter has been estab-lished on the market for decades.

Also in the size of the production plants, this can be easily seen. While PET polymerization plants with a capacity of

PLA will probably be used in the catering field or for films. But compared with fossil-based polymers, the market share is very low (< 1 %) also here, as shown by a re-cent market study (source: FNR). The packaging industry seems to prefer re-cycling over biopolymers.

Current Status of Recycling

Never before has packaging consump-tion and the circular economy been dis-cussed as much as during the past months. And in all fields: in politics, at ex-pert conferences, in the media. Here, PET is the winner among the polymers. PET bottles can be recycled 100 % into new packaging. Recovery systems and so-called “super-clean” recycling processes, which produce recyclates for food appli-cations, have been established for more than 20 years. Bottles of 100 % post-con-sumer recyclate are available. No other packaging plastic offers such a positive balance. Nonetheless, PET bottles are facing heavy criticism in public.

In the media, the PET bottle is seen as the symbol for our throwaway culture, and not part of an already established circular economy. The “circular economy” dis-cussion is connected with marine litter, where packaging – including PET bottles – plays a decisive role. Hereby, everyone agrees that littering of the oceans cannot continue. However, the main sources of litter are countries outside Europe, which have developed the consumption of pack-aging but have not yet built up a recycling infrastructure. These countries must estab-lish a recovery and recycling systems. But when it comes to PET recycling, even highly developed countries such as the USA lie far behind Europe (Fig. 2). The worldwide recycling quota for PET bottles lies over 50 %, but not quite 30 % in the USA (source: Statista, Table 1). A boost in growth cannot be expected. It is estimated that the quota in the USA will increase to 33 % by 2025, and will reach just 36 % in 2030 (source: Kunststoff Information). In

Table 1. PET bottles

and their

reutilization in 2018

(source: Statista)

Country

Philippines

USA

Germany

Quantities in percent

Collected

88.7

95.5

100

Loss

11.3

4.6

0

Recycling

79.8

27.7

97

Incineration

0

10.5

3

Landfill

8.9

57.3

0

Fig. 1. The five largest PET producers with their production capacities in 2017 (source: Statista)

4.5

3.5

3.0

2.5

2.0

1.5

1.0

0.5

0IndoramaVentures

4.2

M & GChemical

2.7

PetroChinaGroup

2.5

Sang FangXiang

2.1

DAKAmerica

1.8

Capa

city

Million t

© Kunststoffe

Kunststoffe international 10/2019 www.kunststoffe-international.com

53Plastics World Market K 2019

i. e. films continue to be the main appli-cation area for PET recyclates. Bottle ap-plications accounted for 29.5 % of the recyclates, and 15.5 % went into fibers. The remaining 15 % were used for strap-ping bands and other products (source: Petcore). The figures show that two thirds of the collected PET bottles were not re-cycled into new bottles, but into PET films and fibers. However, the PET trays and clothing produced from recyclate are not recycled again, and are therefore lost for the PET cycle. Although PET trays are re-covered via the plastic collecting systems, they are presently not recyclable be-

this respect, emerging countries like the Philippines are much further (Table 1).

In contrast, efficient collecting and re-cycling systems have been installed in Eu-rope during the past decades. According to figures from the Petcore Europe associ-ation, European sales of PET bottles in 2017 reached about 3.31 million t. Of these, 58.2 % (1.93 million t) were re-col-lected and recycled for new applications. Consequently, the recyclate quantity was about 2.9 % higher than in 2016. Simulta-neously, however, the return quota fell from 59.8 % to 58.2 % (source: Petcore, Fig. 3). Thanks to the deposit return sys-tem, countries like Germany have already achieved an almost complete return (97 %) of the bottles brought into circulation (source: GVM/Forum PET). In southern EU countries, the re-turn quota is about 30 to 40 % or even lower (source: Petcore). In order to reach the ambitious overall European recycling aims, several other countries are con-sidering the introduction of a deposit on PET bottles. Cur-rently, ten European countries have deposit return systems for one-way bottles: Sweden (intro-duced in 1984), Iceland (1989), Finland (1996), Norway (1999), Denmark (2002), Germany (2003), Netherlands (2005), Esto-nia (2005), Croatia (2006), and Lithuania (2016) (source: Re-loop). Countries such as France, Great Britain, Ireland, Malta, Por-tugal, Turkey, and Romania are planning an introduction, hop-ing to increase the amounts of collected PET. However, not only the return quota by means of deposit return systems is deci-sive. PET returned via the de-posit system is closely controlled and is hardly contaminated. Therefore, PET from deposit re-turn systems is an ideal input material for a closed recycling loop for new PET bottles.

System Losses and Chemical Recycling

With some 40 %, the majority of pan-European recyclates in 2017 were used for film production,

»

ServiceDigital VersionB A PDF file of the article can be found at

www.kunststoffe-international.com/2019–10

German VersionB Read the German version of the

article in our magazine Kunststoffe or at www.kunststoffe.de

© Carl Hanser Verlag, Munich Kunststoffe international 10/2019

54 SPECIAL K 2019 Plastics World Market

dimethyl ester or terephthalic acid bis(hy-droxyethyl) ester. After cleaning, the monomers are then available again for polymerization. The advantage of chemi-cal recycling lies in the fact that it is far more suitable than classical mechanical recycling for handling input flows con-taining e. g. multi-layer films, textiles or polyester floor coverings. As a result, the available quantity of recyclate could be

greatly increased, particularly as a not in-significant amount of the collected PET bottles disappear precisely in these mar-kets. Here, chemical recycling could make an important contribution for circular economy, but it has not yet been imple-mented on a commercial scale.

Conclusion

In summary, the age of circular economy for PET has already begun. With this ma-terial, much has already been imple-mented industrially – a situation from which other plastics are still a long way off. Of course, the number of collected PET bottles worldwide is far too low, also in Europe. A Europe-wide return quota of less than 60 % is anything but satisfactory. The structures and processes are estab-lished and economically viable. W

Dr. Frank Welle, Freising, Germany

cause of the integral sealing and multi-layers. Moreover, the new German Pack-aging Act now also classifies them as such. Because this is disadvantageous for calculating the collection fees, and also for the image of PET packaging, it is to be changed. Various syndicates have joined forces, with the aim of also recycling PET trays. However, there is still a long way to go. For applications in the food industry, the implemented procedures must be approved by the European Food Safety Association (EFSA). This process requires large amounts of experimental data on the concentration of possible post-con-sumer substances and decomposition products as well as the cleaning efficien-cy of the recycling operation.

Currently, chemical recycling is ex-periencing a renaissance. Chemical recyc-ling procedures were developed decades ago. But for economical reasons, they were never implemented on a commer-cial scale. And PET also scores here. As op-posed to polyolefins, the breaking point for chemical recycling is already included in the ester bond. Hereby, the polyester is hydrolyzed to the monomers ethylene glycol, terephthalic acid, terephthalic acid

Fig. 2. Efficient collecting and deposit return systems are the prerequisite for sorted and 100 %

reusable PET flakes from post-consumer waste. Here, also industrialized countries are still facing

difficulties (© Erema)

Fig.3. Collected quantities and the return quotas for PET bottles in Europe (source: Petcore)

Year

2200

kt

1800

1600

1400

1200

1000

800

600

400

200

0

70

60

50

40

30

20

10

0

%

2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017Co

llect

ed P

ET b

ottle

s

Retu

rn q

uota

41.146.0 48.4 48.3

51.0 52.355.9 57.0 59.0 59.8 58.2

© Kunststoffe

ENTRANCE NORTHFirst and upper floor

Come and visit

us