Showing posts with label recycling. Show all posts
Showing posts with label recycling. Show all posts

Tuesday, March 25, 2014

K-Cups and the Environment



Dear EarthTalk: What is the environmental impact of those “K-Cups” everyone seems to be using nowadays to make coffee at both home and office?                   
                                -- Chris B., Stamford, CT

K-Cups—those little one-serving coffee containers that allow people to brew one cup at a time in a specially designed Keurig brewing machine—are all the rage these days. Each K-Cup is made up of a plastic outer container with one cup’s worth of ground coffee and a small filter inside, capped off with a foil lid. They go into Keurig brewing machines which pierce the bottom of the K-Cup with a nozzle that then forces hot water through the coffee grounds and filter, and then out into the drinker’s cup. K-Cups and the Keurig brewers are convenient and require little to no clean-up while producing gourmet quality coffee for a fraction of the price that a retail coffee shop would charge.

Credit: Aaron Paxson, courtesy Flickr
Environmentalists’ beef with the Keurig system is in the single-use, non-recyclable nature of the packaging, given the implications for our waste stream. The individual parts of a K-Cup (plastic, paper and foil) could theoretically be recycled on their own, but the combination is too small and messy for recycling facilities to be able to sort. So our only choice is to throw the whole K-Cup pack, lock stock and barrel, into the garbage. Each pound of coffee consumed sends 50 K-Cups to the landfill. And with upwards of 17 million U.S. households and offices possessing Keurig brewers these days, billions of K-Cups are already ending up in landfills every year.

Keurig Green Mountain, the company behind the K-Cup revolution, is on the case about the bad environmental reputation it is developing over the issue. As a first step, it launched its Grounds to Grow On program in 2011 whereby office customers can purchase K-Cup recovery bins and fill them up with spent K-Cups. When the boxes are full, they are shipped to Keurig’s disposal partner, which turns the used coffee grounds into compost and sends the rest out to be incinerated in a “waste-to-energy” power plant. Critics point out, though, that waste-to-energy is hardly green given the airborne pollutants released from incinerator smokestacks and the fact that, in the words of Julie Craves of the Coffee & Conservation blog, recycling is the enemy of the never-ending stream of garbage needed to feed waste-to-energy facilities.

In 2012, Keurig Green Mountain, realizing it still had a lot of work to do on sustainability matters, undertook a lifecycle assessment across its product lines—and set ambitious sustainability targets to achieve by 2020. Chief among them is to make all K-Cups 100 percent recyclable. Other goals include ensuring responsible sourcing for all its primary agricultural and manufactured products, reducing life-cycle greenhouse gas emissions of its brewed beverages by 25 percent compared to the 2012 baseline, and achieving zero waste-to-landfills its manufacturing and distribution facilities.

Those who love the Keurig system but are ready to forego the environmental guilt sooner than 2020 do have some options. Julie Craves reports that used K-Cups can actually be refilled with ground coffee and reused. An easier option might be buying a reusable K-Cup—most of them are made out of plastic with a stainless steel mesh filter. Still the best choice for the environment, however, might be getting the old traditional coffee pot out of storage and brewing up several cups at once—just like the old days.

CONTACTS: Keurig Green Mountain, www.keuriggreenmountain.com; Coffee & Conservation Blog, www.coffeehabitat.com.

EarthTalk® is written and edited by Roddy Scheer and Doug Moss and is a registered trademark of E - The Environmental Magazine (www.emagazine.com). Send questions to: earthtalk@emagazine.com.


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Saturday, September 28, 2013

Plastic Bag Waste Used to Make Materials for Nanotechnology

Types of Carbon Nanotubes
Types of Carbon Nanotubes (Photo credit: Wikipedia)
University of Adelaide researchers have developed a process for turning waste plastic bags into a high-tech nanomaterial.

The innovative nanotechnology uses non-biodegradable plastic grocery bags to make 'carbon nanotube membranes' ‒ highly sophisticated and expensive materials with a variety of potential advanced applications including filtration, sensing, energy storage and a range of biomedical innovations.

"Non-biodegradable plastic bags are a serious menace to natural ecosystems and present a problem in terms of disposal," says Professor Dusan Losic, ARC Future Fellow and Research Professor of Nanotechnology in the University's School of Chemical Engineering.

"Transforming these waste materials through 'nanotechnological recycling' provides a potential solution for minimising environmental pollution at the same time as producing high-added value products."

Carbon nanotubes are tiny cylinders of carbon atoms, one nanometre in diameter (1/10,000 the diameter of a human hair). They are the strongest and stiffest materials yet discovered - hundreds of times stronger than steel but six times lighter - and their unique mechanical, electrical, thermal and transport properties present exciting opportunities for research and development. They are already used in a variety of industries including in electronics, sports equipment, long-lasting batteries, sensing devices and wind turbines.

The University of Adelaide's Nanotech Research Group has 'grown' the carbon nanotubes onto nanoporous alumina membranes. They used pieces of grocery plastic bags which were vaporised in a furnace to produce carbon layers that line the pores in the membrane to make the tiny cylinders (the carbon nanotubes). The idea was conceived and carried out by PhD student Tariq Altalhi.

"Initially we used ethanol to produce the carbon nanotubes," says Professor Losic. "But my student had the idea that any carbon source should be useable."

The huge potential market for carbon nanotubes hinges on industry's ability to produce large quantities more cheaply and uniformly. Current synthesis methods usually involve complex processes and equipment, and most companies on the market measure production output in only several grams per day.

"In our laboratory, we've developed a new and simplified method of fabrication with controllable dimensions and shapes, and using a waste product as the carbon source," says Professor Losic.

The process is also catalyst and solvent free, which means the plastic waste can be used without generating poisonous compounds.

This research has been published online ahead of print in the journal Carbon.

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The above story is based on materials provided by University of Adelaide.

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