Comments on: AskPablo: Glass vs. PET Bottles

By: Alex Huber

Alex Huber — Mon, 13 Jul 2009 22:21:06 +0000

I have spent all day researching the carbon footprint of bottles vs. other packaging, and this was the most concise.
Do you know anyone who has done a good job on the Carbon footprint of Bag-in-box?
Cheers,
Alex

By: Anonymous

Anonymous — Sun, 31 May 2009 17:10:01 +0000

This discussion so far has mostly ignored the large amount of petroleum used to make glass because of the high melting point of silica.

By: aram

aram — Sun, 29 Mar 2009 21:10:25 +0000

Dear Pablo
we would like to fill beer in mono layer pet bottle ,please let us know have you any idea for sterilization or pasteurizer filled beer bottle.
thanks
wishes

By: Alan

Alan — Fri, 27 Mar 2009 02:18:55 +0000

Glass 100% recyclable and reusable. Plastic bottles reusable but seriously how many plastic bottle can one reused before having too much that they have to be thrown out. Plastics have many issues, i.e. chemicals that may be harmful like gender altering hormones. Plastic bottles are more convenient but maybe that is a bad thing. So maybe we consume less soda since its a bit more inconvenient to carry around. Isn’t that better for us healthwise? Plastics, when it come to packaging food, is usually the worst solution for the environment and personally.

By: Mackinnon

Mackinnon — Tue, 27 Jan 2009 16:36:30 +0000

Pablo,
Good discussion! Thanks for the info. My understanding is that there are still significant gains to be made with regards to reducing the weight of glass while also increasing its strength. This would certainly make glass more competitive.
http://blog.cleantechies.com/2009/01/26/chasing-cleantech-in-the-glass-bottle-industry/

By: gassan saliba

gassan saliba — Wed, 14 Jan 2009 13:18:53 +0000

dear ,
in my country there is a 19 liters drinking water delivery,some bottles are made from polycarbonated plastics and other from pet…
please can you reply telling me which kind of plastic can be refilled by the bottling factory and for how many times? and why?
thanks in advance….

By: George Zboril

George Zboril — Sun, 10 Aug 2008 13:13:53 +0000

We seem to be unreasonably biased:
- Against plastics,
- For biodegradable materials
- For the technology of yesteryears.
What is it we want to achieve? Lower GHG emissions? Lower use of nonrenewable resources? Less volume in landfills? Lower pollution of ground waters or air? Something else?
Glass containers use a lot of energy and generate a lot of GHG (see discussions above). Then we have to take into account that return bottles require washing and sterilization, hence energy for hot water and chemicals. Also the disposal of the dirty water is part of the equation. The bottles last for about 20 return trips, what happens to them afterwards?
Biodegradable materials make sense only if they are composted at the end. If they are land filled they rot quite slowly generating potent GHG (methane) and require sealing the landfill site to prevent contamination of ground water by leachate. That further slows the decomposition process. The landfills are unstable for many years. Biodegradable plastics exist (polylactates) but they have to be separated for composting, else we would contaminate the compost by other plastics.
Plastics are light, and except in some instances are superior to all other options. Some are recycled (PET bottles) and it does not make difference that they are converted to fibres where they replace virgin resin. The energy in plastics can easily be recovered by burning and producing electricity and heat. Also when buried they cannot contaminate air or groundwater.
My feeling is that plastics should be the materials of choice. However, the local conditions are important: Is there a composting facility? Do we collect and use the landfill off gases? Is there an incinerator and is it used for generating energy? And so forth.
One thing though puzzles me: Most of the GHG are generated by burning fossil fuels in our SUVs and our oversize homes, most of the landfill space is taken by paper, like the fliers we discard without reading. Should not we address these issues with the same vigor?

By: Geoff Garcia

Geoff Garcia — Wed, 06 Aug 2008 14:54:06 +0000

This is a terrific topic and I think you have done an excellent job of analyzing this issue from the transportation and storage end.
Nobody is going to argue that plastics are lighter and smaller and that transportation energy will be saved by going with plastics.
However, what about:
1) the recycle-ability of plastic vs glass?
-Can all plastic be recycled? can all glass be?
-What is the reality of recycling for the two?
2) the amount of pollution from production of the different containers?
-Which process creates more contaminants?
3) the amount of energy needed for production of the different containers?
-Which process takes more energy?
4) of those container that are NOT recycled, what is the difference in environmental impact?
My point is that there are many facets of the glass vs plastic debate, I hope folks don’t pick a “winner” based solely on the transportation & storage argument that was initially presented.

By: Tom

Tom — Mon, 14 Jul 2008 09:57:49 +0000

I believe your calculations for g/g GHG for PET emissions are very wrong. When you say it’s 15x more for a plastic bottle, that is based on your incorrect calculations – 30 x 3.723 is not in fact 11.7 but 111.7. This then follows through your calculations, and should be 133.5kg total not 33.5kg. It still proves your point, but less so.

By: Rauf

Rauf — Sat, 26 Apr 2008 08:21:38 +0000

is pet bottles and pet g bottles sterilized with gama radiation

By: Aaron B. Martin

Aaron B. Martin — Sun, 09 Sep 2007 00:24:30 +0000

When I was a boy I bought soda, etc. from machines in glass bottles and right next to the machine was a crate to place your empty bottle. There was no deposit return, we just turned them in. When my mother bought milk, Juice, and soda at the grocery store they were in glass bottles and we returned them when we went to the grocery again. These bottles were washed, sterilized and reused. It was neat to get a really old bottle from time to time as a kid. The logos etc were painted on the glass, not wrapped on the bottle with paper or plastics. This was the 1980s in the US. It worked very well, it was efficient, clean, and I imagine more energy efficient and cheaper. Also, it occurs to me that sense glass bottles with metal caps are not penetrated by air etc. as plastics are that the shelf life and quality of the products was probably higher. It also occurs to me that at that time a glass bottle of coca cola was $.50 then and if you apply 3% inflation over lets say 25 years then it should cost about $1.05 now, but in every machine I can find now a plastic coca cola cost $1.25. We are filling land fills, arguably saving little to no energy, and saving no money.
Tell me again how are these plastic bottles better than reusing glass bottles.
Maybe I am missing something.

By: Keith R

Keith R — Fri, 17 Aug 2007 16:09:07 +0000

Chris, you noted that
“For some reason, ‘virgin’ PET is required for beverage bottles. (Not sure the exact reasons).”
Mainly because health authorities (US-FDA, etc.) regulating the placing of beverage products on the market have resisted authorizing it until they can be assured that the tech exists to provide high-quality recycled PET that does introduce contaminants into the beverage. Such tech has been around for several years, but only recently have the health authorities been willing to entertain changing their regulations on “materials and article in contact with food” to reflect the current state-of-the-art.
Keith R

By: Parag Raval

Parag Raval — Fri, 10 Aug 2007 11:09:24 +0000

Dear Pablo,
While doing research on the PET bottles, I found this very interesting post of yours on the glass vs. PET bottles. Your conclusion was “This adds up to 33.5 kg (11.7 kg + 21.83 kg) of CO2 for every 1000 PET bottles shipped 1000 km.” So 33.5 grams per bottle transported 1000 km?
I am researching on a technology that converts plastics back into fuel. It would take 55 of the PET bottles (or 1.842 kg of CO2) in your example to generate 1 liter of gasoline. Since this liter of gasoline is not using any “new” crude oil but is simply extracted from waste plastic that would have only added to the non-biodegradable mess at the city dump, what kind of “carbon neutrality” (or carbon positive impact) is achieved by this process? I don’t know if the environmental impact of the lesser load on the city dump can be measured, but what about each liter of gasoline generated from recycled plastic instead of freshly extracted crude oil? How does that lessen the CO2 impact?
I am not a member of any of the lists you regularly write on, but would you be kind enough to respond to me at this e-mail ID?
Thanks in advance and keep up the good work!
Regards,
Parag Raval

By: Chris Hayes

Chris Hayes — Tue, 10 Jul 2007 19:42:37 +0000

Hi How many times do i need to refill / recycle a litre glass bottle, with water at home…For it to compensate GHGs produced during making etc when compared to buying the same water volume in plastic or pet bottles from a store?