Should We Stop Throwing Food Away on Bio-Plastics?
by Anonymous - Apr 30th, 2008
In the past year bio-plastics -- made from maize, sugarcane, wheat and green sugar beets -- have garnered a huge market growth, upwards of 20%, but with food shortages on the rise, this eco-solution has been receiving mixed reviews. Some experts argue that trading-in plastics for this bio-alternative can put increased pressure on world food supplies and damage the environment.
A recent Guardian article by the paper’s Environmental Editor John Vidal focused on the shortcomings of the plastic resin known as PLA (Polylactic Acid), which is being used as an eco-alternative by large grocery store chains and Wal-Mart. Says Vidal:
Just because it's biodegradable does not mean it's good.
Vidal argues that PLA degrades without oxygen, releasing methane, a greenhouse gas 23 times more powerful that carbon dioxide (CO2), and also that it is unable to fully break down in landfills. For PLAs to degrade in composts, they need to be heated for several days before beginning to rot. Commercial composters have the tools to heat PLAs, but few cities operate such plants.
Critics also contend that PLAs can't be recycled easily. Recyclers are geared up to handle bottles made of an oil-based plastic called PET. PLA and PET are nearly indistinguishable, so separating them requires costly infrared sorting equipment. Many small-scale recyclers separate different plastics by mechanical methods or even by hand.
Bio-plastic champions argue that the product can make carbon savings of 30-80% compared with conventional oil-based plastics and can extend the shelf-life of food. As well, manufacturers such as NatureWorks argue for patience: bio-plastics are still new and eco-issues can be worked out:
We're dealing with new materials. Just because there are disruptions now, doesn't mean it will be a bad thing in the longer term.
At a recent bio-plastics conference, manufacturers were touting the creation of a new green polyethelene made out of sugarcane called bio-polyethylene (bio-PLA), made by the Brazilian petrochemical company Braskem. It is purportedly identical to fossil-based plastics and so manufacturers claim it can be recycled along with PET in the same waste stream. Braskem claims:
The machinery will never know the difference.
But the company also unwisely takes its promotional argument one step further, falling into a trap of circular reasoning. Braskem is saying the new plastic could also be a new source for bio-fuel, because catalysts or microwaves can convert the polymers into gasoline. This could be good news for the bio-fuels sector, Braskem says, as recycling bio-plastics into fuel could allay concerns about the use of food crops in bio-fuels production.
Has Braskem forgotten that food crops are used in bio-plastics production in the first place, and don't they realize that putting bio-plastics in the waste stream is equivalent to throwing away food?
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Looks like are you the ones
Looks like are you the ones forgetting that the sugar rits used by the brazilians are NOT food...
Like always, the fossil´s lobby doing what it does best: be at the top to the very last.
I guess we just have to enjoy armagedon.
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