Polyester – to recycle or not to recycle?

12 01 2011

I know it’s hard to imagine that the lovely fabric you’re eyeing for that chair – so soft and supple and luxurious – is just another plastic.

But because 60% of all polyethylene terephalate (PET – commonly called polyester) manufactured globally is destined to be made into fibers to be woven into cloth,  and because  polyester absolutely dominates the market, and because the textile industry has adopted using recycled polyester as their contribution to help us fight climate change, I think it’s important that we keep up with topics in recycling plastic.

”A Tribute to PET Bottles“ by Czech Sculptor Veronika Richterová

If using recycled polyester is good, then using “post consumer” PET bottles  is deemed the highest good.  But an interesting thing is happening with PET bottles and recycling, according to a study published in August, 2010, by SRI Consulting, which is, according to their web site,  the world’s leading business research service for the global chemical industry (www.sriconsulting.com).  The study, PET’s Carbon Footprint: To Recycle or Not to Recycle, caused more than a few ripples because it concluded that in many cases recycling bottles is no better — and could be worse — than landfilling.
The study’s key finding — widely reported — is that a recycling facility needs to recover at least 50 percent of the material it takes in if it is to achieve a more environmentally favorable carbon footprint than simply disposing directly to landfill.  The key is to improve yields , especially in sorting and to a lesser extent, in reprocessing.

This study addresses two key questions:

  • should we recycle plastics?
  • what are the carbon footprints of virgin (vPET)  and recycled PET (rPET)

In order to calculate the carbon footprint of various PET products, the study  calculated the carbon footprint for PET bottles used to package drinks from “cradle to grave,” i.e., extending from production of raw materials (primarily oil and gas) through to disposal of all wastes. The study considers a base case—bottles are used by consumers in northwest Europe, collected in a curbside system and sent on for sorting and recycling—and variations on that theme, including PET-only take-back (as currently practiced in Switzerland) as well as no recycling (with scenarios of “all landfill” and “all incineration”). Sensitivities of all major variables were assessed.

The study concludes that the curbside take-back systems are no better than landfill, in terms of carbon footprint. From a carbon-emissions standpoint, it would be just as well to bury used bottles as to recycle them, and either would be a better option than burning them.  The study found that landfilling PET bottles from certain systems rather than incinerating them could reduce carbon footprint by 30%.  Call it “carbon capture and storage” on an economy budget.  The key is to have the room – and if you read Thomas Friedman’s Hot, Flat and Crowded you may be hard pressed to agree that there could ever be anyplace on the planet with room!

SRI report author Eric Johnson told FoodProductionDaily.com that transportation and processing costs, as well as low yields of pure PET (of below 50 per cent) from curbside recycling collections such as Germany’s DSD ‘Green Dot’ programme,  warranted SRI’s conclusion. (read article here)

Johnson said: “In terms of resource squandering [of oil in particular], if it takes more resources to recycle bottles …  than to produce units from virgin PET then this is irresponsible. If you’re going to recycle…do it properly.”

Jane Bickerstaffe, director of the UK Industry Council for Packaging and the Environment, concurred with Johnson’s point that rPET purity was a significant hindrance to worthwhile recycling, given that it affected recoverable PET levels: “Quality of recyclate is a big issue because the energy costs to separate out contaminants and clean the polymer are significant,” she said. (1)

As you might expect, there was a bit of an uproar over the study.

Casper van den Dungen,  EuPR PET working group chairman,  condemned SRI Consulting’s report:  “By applying SRI Consulting’s results we would …  lose valuable [rPET] material in landfills. The model used is intrinsically wrong, as in reality landfill should be avoided as a starting principle.”  (2)

Antonio Furfari from EuPR added: “The wrong signal is that landfill is good for environment. Landfilling is not acceptable for environmental and resources efficiency reasons, and CO2 is not the only environmental variable.” (3)

And yet, Jane Bickerstaffe had this comment: “It’s worth noting that landfilling inert materials like PET is just like putting back the sand, granite etc. that was dug out of a hole in the ground in the first place.  Inert materials are benign, whereas biodegradable materials such as cabbage leaves and potato peelings generate methane in landfill and have a negative impact on climate change.” (4)

The findings of this study hinge on how the plastics are collected.  Recycling programs using curbside collection typically displace less than 50% of new PET (polyethylene terephthalate). Community programs with plastic bottle take-back, mandated separate collection, or deposits on bottles tend to report much higher displacement rates. For regions that already have a recycling infrastructure, the aim should be to boost recycled PET (rPET) displacement of virgin PET (vPET) significantly above 50%.   The key seems to be in increasing yields rather than improving collection rates.  In countries where there is no recycling infrastructure, the best choice may well be to landfill bottles.”

It seems to me that, in consideration of “should we recycle plastics”  –  the answer is (as it almost always is): “it depends”.   Should we use only carbon footprint as a yardstick?  Sometimes you have to pull back and take in the big picture; as one blogger put it, “It’s unconscionable to pay out the nose for foreign oil so that we can produce more soda bottles to package up products that make our population fat and unhealthy.”

And how does all that trash get into the oceans?  How does that figure into this equation?

Hey, I never promised answers.

(1)  Bouckley, Ben; “Plastic recycling body slams report advising countries to landfill PET bottles”, FoodProductiondaily.com, September 2, 2010

(2)  Ibid.

(3)  Ibid.

(4)  Ibid.


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3 responses

12 01 2011
gina mastio

Apart from the carbon footprint yardstick, surely its extremely important to note that we are creating clothing such as the post consumer” PET bottle fleeces, placing toxic chemicals in close contact to our bodies that were never designed to be worn on the skin, creating a host of health issues longterm. (as noted in “Cradle to Cradle”)
And is it not common sense to now create new biodegradable ‘plastics’ such as from corn starch, or otherwise glass, and ban outright production of non biodegradable plastics? why continue a bad path when it is known to be extremely bad?

13 01 2011
oecotextiles

Thanks for the comment, and I agree that these plastics can very well cause health issues longterm because of their chemical composition. However, the chemicals used during processing of the fibers into fabric (the softeners, the dyes, etc.) can pose just as great a threat as the chemicals used in creating the fiber. So if you could find a polyester fabric that is processed to the GOTS standards it would be much better for you than the standard, conventionally processed recycled polyesters. Assuming, of course, that you’re willing to use a synthetic. But I have to say that when I shop for clothing now it’s very hard to find even 100% natural fibers. I agree that research should be done into biodegradeable plastics (and it is!) but the issues are tremendous – for example, each plastic has certain specifications. I did read about one new company is producing mushroom based packaging material to replace those styrofoam peanuts (see http://www.greenbiz.com/news/2010/08/10/mushroom-based-packaging-98-percent-less-energy-styrofoam). It looks very promising. Little steps!

29 03 2013
Chris Canaday

I suggest that the most ecologically friendly option is to use the PET bottles to build vertical gardens (as I have figured out how to do), in the city where their contents are consumed. These could be planted with food plants, thus contributing to the sustainability and security of food production, while reducing transport costs and impacts … and making the city a better place to live.

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