Pouring Oil on the Ground
Ethylene-based plastic packaging includes PET, HDPE, and LDPE. It's everywhere: soda, water, and juice are all bottled in it. The store clerk puts these items in a bag made from it. Even vegetables are increasingly packaged in PET as opposed to PS (polystyrene). PET bottles are lighter than glass, resulting in a 40% fuel savings when transporting some liquid products (1). Plastic grocery bags are cheaper than their paper counterparts (2). And, unlike their polystyrene counterparts, they're economical to recycle. Most communities have public or private recycling operations that collect PET (plastic #1) and HDPE (plastic #2), and many accept LDPE (plastic #4). Walmart (among other stores) collects used shopping bags for recycling. Yet too often, these plastics find their way to the landfill— or worse, the side of the road.
Recently, I watched a plastic Walmart bag float by in the wind, miles from the nearest store, and wondered how much energy is lost when we fail to recycle our plastic. The information isn't easy to come by, at least for a non-chemist like myself. An afternoon searching the web taught me that these products are all made by cracking light hydrocarbons into ethelyne, which is subsequently catalyzed into polystyrene or polymerized into PET, HDPE, or LPDE (3). So the primary ingredient is crude oil. In fact, 4% of the world's oil production goes into making plastic grocery bags (4). That's four out of every 100 barrels of oil pumped out of the ground!
One report suggests that the energy used to make 8.7 plastic grocery bags would power a car to go one kilometer (5). That's roughly 100 bags to a gallon of gas. While this is 70% less energy than used making a paper bag, it's still a lot of oil. If, as is reported, the U.S. uses 30 billion plastic grocery bags a year (6), that's the equivalent of about 300 million gallons of gasoline!
I'd love to see all of us switch to reusable cotton (canvas) grocery bags, but that's not the point of this post. The point is this: the United States imports over half the oil it uses from other countries (7). During January 2007, the U.S. average oil imports of 9.6 million barrels of oil per day! (8)
A recyclable plastic bottle or bag sent to the landfill (or worse, tossed on the roadside), is wasted oil. And it's not oil produced by wage-earning Americans who'll spend that money in our own economy, but oil produced in another country, that we paid for, the proceeds of which might well go to countries or groups that do not have our best interests at heart.
Failing to recycle plastic containers and bags is a lot like buying oil and pouring it on the ground. With today's economic, environmental, and political concerns, that's not just wasteful— it's criminal.
Sources:
(1) http://www.kenplas.com/project/pet/
(2) http://en.wikipedia.org/wiki/Plastic_bag
(3) http://en.wikipedia.org/wiki/Ethylene and http://en.wikipedia.org/wiki/Polyethylene_terephthalate
(4) http://www.vipirg.ca/publications/pubs/student_papers/05_ecofootprint_plastic_bags.pdf
(5) http://www.abs.gov.au/ausstats/abs@.nsf/94713ad445ff1425ca25682000192af2/2498b7e0c5178282ca256dea000539bc!OpenDocument
(6) http://www.deliciouslivingmag.com/magazine/index.cfm?fuseaction=article&articleid=222
(7) http://www.lookoutmtn.com/Documents/Sources_of_United_States_Oil_Supply.pdf
(8) http://www.eia.doe.gov/pub/oil_gas/petroleum/data_publications/company_level_imports/current/import.html
Comments