Paper versus Polystyrene Cups
Posted by Max Dunn Fri, 21 Nov 2008 15:29:00 GMT
I just finished my Sustainable Design class in the Stanford Continuing Studies program taught by Mark Martin. It was a really interesting, well taught class and I learned a lot.
One of the main points that Mark made was that it is difficult to tell how eco-friendly a product is without a in-depth study. As an example, he had us discuss which we thought was more eco-friendly: paper or polystyrene coffee cups. (Polystyrene is sometimes called Styrofoam or Polyfoam.) We all pretty much all agreed that paper cups were better, and then Mark showed us this study:
On almost every count, except cooling water and biodegradability, the polystyrene cups are more eco-friendly.
In a more recent study polystyrene was also found to be better:
In raw material requirements the paper cup required about 2.5 times its finished weight of raw wood and about the same hydrocarbon fueling requirement as is needed for the polystyrene foam cup. To process the raw materials about six times as much steam, 13 times as much electric power, and twice as much cooling water are consumed to produce the paper cup as compared to the polystyrene foam cup. Emission rates to air are similar and to water are generally higher for the paper cup.
Another interesting ramification this study pointed out is that in a wet landfill, the polystyrene will remain stable while the paper will decompose giving off methane gas and contributing to the instability of the land surface.
This just goes to prove what Mark taught in this class – it isn’t always obvious which products are eco-friendly.