How Disposable Cups Can Become Biofuels


Tim's CupPhoto: waferboard

The paper cup, while viewed by most as a better alternative to the styrofoam cup, is hazardous to the environment. One might be inclined to think that since they’re made of paper, they’re recyclable, and thus a good thing. Obviously not as good as a reusable travel mug, which can be used for years and years, the paper cup has many flaws.
Garbage CupPhoto: bgilliard

In 2006, over 6.5 million trees were used for the production of 16 billion paper cups, and that’s just in the US. Another four billion gallons of water were used in their production, and the resulting waste totaled a whopping 253 million pounds. Even though the cups consist of 95% renewable resources in the form of wood chips, the paper cups are generally coated in some form of plastic so that they won’t leak. As a result of the coating, the cups are slow to breakdown, and if composted anaerobically, may release methane.
Overflowing Garbage CanPhoto: Jason V

Knowing that paper cups are so harmful to the environment, is there anything that can be done to reduce the damage being caused by our love of paper cups? It goes without saying that world governments demanding every man, woman and child run out immediately and purchase reusable travel mugs probably wouldn’t work. City-wide programs have been put in place to ban single-use plastic bags, and they seem to be catching on. Perhaps the next step should be a ban on single-use paper cups?

Even with the immense efforts to ban plastic bags, there are still an awful lot of them circulating in cities and towns around the world, and it will most likely be many years before we’re able to eliminate the issue completely. The same time-frame would likely apply to the elimination of these cups. But what if used paper cups could be put to good use?
Ethanol from Wood chipsPhoto: Argonne National Laboratory

That’s exactly what Microbiologists Richard Sparling and David Levin at The University of Manitoba have been researching since 2009. Since there are four Tim Horton’s outlets on campus, the number of cups seen in the garbage each day was staggering. Mr. Sparling was recently quoted in an article, stating: “Knowing that these are not sent away for any type of recycling at this time, we thought they would make excellent food for the bacteria that we use to make biofuels such as ethanol or even hydrogen. “Since the beginning of their project, they’ve had some success, being able to generate 1.3 litres of ethanol for each one hundred discarded cups.
So Many CupsPhoto: Terry Johnston

The cups, once collected, are shredded to such an extent that they look like cotton candy, and are then put into a bioreactor which controls temperature and acidity level to the bacteria’s liking. The bacteria begin to break down the “mulch”, releasing ethanol and hydrogen. Having tried other manufacturer’s paper cups, the researchers have found that the bacteria are able to process those from Tim Horton’s the fastest.
CoffeePhoto: cyclonebill

Because they haven’t received any funding for their project, the researchers estimate it will take between three and five years before the process could be commercialized. While that may seem like a way off, it will probably be faster than totally eliminating the single-use paper cup from our culture.