Bioplastics: The "Other" Biofuel?
by Jeremy Elton Jacquot, Los Angeles on 04.26.08
If there's one thing we've learned over the last few weeks, it's that burning large quantities of staple foods to produce a relatively small amount of fuel is a thoroughly misguided practice -- with grave implications for the world's most vulnerable populations. And though the barbs directed at biofuels from all sides have been merited, we must not forget one of the other main culprits in this global food crisis: bioplastics.
A new Guardian study reported on by environment editor John Vidal reveals that efforts by industry and supermarkets worldwide to replace conventional plastic with bioplastic bags made from plants has caused consternation among environmentalists and consumer confusion. These bags, which are typically made from corn, wheat or sugarcane, may increase GHG emissions, the study found, because they either require higher temperatures to decompose or can't be recycled -- and therefore end up clogging landfill sites.
Corn-based bioplastic packaging is made with polyactic acid (Pla), which closely resembles typical PET (polyethylene terephthalate) plastic, is widely used by large food groups and grocery chains, including McDonald's and Wal-Mart, and bottlers. Though proponents claim Pla helps extend products' shelf life and cut emissions production during the manufacturing process, the study found that it barely broke down and could only be composted in anaerobic digesters, all of which do not take packaging. Pla bags that end up on landfill sites release methane, a very potent GHG, when they degrade.
Moreover, its inclusion in recycling operations can contaminate the other materials and make recycled (conventional) plastics unsaleable. To handle bioplastic packaging, recycling companies would need to invest in very expensive, cutting-edge machinery that could extract the Pla from waste.
Then there is the problem with so-called "oxy-degradable" plastic bags, which supermarkets are promoting as the "sustainable" alternative to PET bags. Although it's true that these bags, which contain an additive that facilitates the breakdown of plastic, are, in fact, biodegradable (in principle), the fact that they eventually end up in an anaerobic landfill site means they won't degrade effectively.
As Chris Goodall, an environmental author and analyst points out: "People think that biodegradable is good and non-biodegradable is bad. That's all they see." In practice, that distinction is not always so evident. As with biofuels, we need to find better alternatives to feed stocks and ensure that the bags degrade properly -- both not easy objectives. Perhaps more bags made out of cow poop?
Via ::The Guardian: 'Sustainable' bio-plastic can damage the environment (news website)
See also: ::Using Maple Syrup To Make Bioplastics, ::Earthshell Opens First Bioplastic Factory in Missouri
What have I been saying about PLA?
How about just using cloth bags, period, and charging consumers a quarter a bag for paper/plastic.
If all of the people in NYC and Boston and most of the people in Europe can figure out how to carry their own cloth shopping bags, so can everyone else.
Some of the food containers I get are made out of corn (buy local). The recycling code is stamped with a 7 so I toss it into the mixed plastics bin.
According to the folks at Natureworks as little as 0.1% can contaminate the process but refers specifically to mixing it with PET (#1) plastic.
http://www.americanrecycler.com/0108/growth.shtml
So I'm assuming it's still safe to recycle provided that it's put into the correct bin.
As for producing methane, that's what it's supposed to do if it is biodegradable.
you people do realize that....
there is no such thing as global warming???
and often recycling takes more energy than producing new products???
go to junkscience.com and get a clue,, then you won't have to feel guilty all the time. :)
Friends don't let friends use corn...
"there is no such thing as global warming"
and Santa Claus and the Loch Ness monster and God...
warming in the Middle Ages... warming all of the time... it's cold some places... we did nothing to affect it...
It seems that people decide if global warming is real (and human-driven) and stay there. Don't argue with them to convince them. I bet the rate of converts is less than believers in any religion.
I will say that recycling can take more energy, but I am doubtful on how that's calculated... especially if it doesn't calculate shipping and harvesting for new items.
Commenting on the post: we got into a bad habit of using one-use items. Now there's a move towards reusable. Don't go back people, don't look back!
I feel that most of the issues raised by this article are "non-problems":
1 - plastic bags are normally separated from plastic bottles during recycling, and mechanical sorter that separate by material type are already available
2 - methane production during biodegration ... has anyone heard of decomposition?
3 - the article seems to draw an implicit parallel between biodegradable bags and food crisis, even if the amount of corn used to produce these bags is minuscule compared to the total comsumption
Really, the biggest point of PLA bags is that they can decompose during a relative short time period, and do not end up cloggin the ocean _forever_
May be made out of cow poop, or may be out of cow dung. :) But not from plastic. We need to use natural components, but not from plant materials.
What makes more sense:
1) using oil to make plastic bags that stick around in landfills since they only photo degrade and using corn to make ethanol that delivers lower mpg
OR
2) using corn to make biodegradable plastic and use the oil saved to make gasoline
?
There are some new efforts to produce High Density Polyethylene (HDPE) plastics from sugar cane ethanol. That's not going to compete in any material way with food production and it offers dramatically higher yields of plastics per acre than corn or soy can.
What kind of study is this. Bioplastics are a start. First, oil-based plastics are the worst kind of offender to recycling programs. They clog the machines that perform the recycling and therefore raise the costs of recycling other materials. If cities were to use a separate food and green recycling program(like San Francisco), then the bioplastic bags would be reused to put compostable waste into. Generally, plastic bags that are even collected at your local store are not recycled. They really have no value and many companies that say that they are being recycled are generally lying. The recycling is done pre-consumer. The blanks that are made in the manufacturing of the plastic bags are easily recyclable and are CLEAN. Bags that people bring to the store are not clean and can have contaminants. Ethanol from corn is a huge problem, not bioplastic bags from corn.