Making the Environmental Case for Reusable PET Bottles

Abstract

In order to meet increasingly demanding environmental regulations, redesigning mass-manufactured products for sustainable reuse is of great interest. A good percentage of the estimated world daily production of billion or so single-use Polyethylenterephtalate (PET) bottles does not get recycled. Therefore, the availability of such a bottle to meet multi-use requirements would have dramatically positive effects toward reducing plastic waste. While autoclaving is not recommended for PET, other (gas) sterilization methods are suitable. With different end of life scenarios (reuse, recycling, or re-manufacture), the “Energy End of Life” potential is a measure of the energy that could possibly be recovered at the end of life of a product. Even for a single reuse of a typical 500 ml PET bottle, our findings estimate that one reuse of 500 ml bottle will save about 1 MJ per bottle. As compared with the recycling option, our estimates calculate 74% more energy savings and produce 182% less CO2 for one reuse option. For the estimated world daily production of one billion bottles, assuming all bottles are reused only once, the resulting energy savings are estimated at 0.365 * 1018 J (or 0.365 Exa Joules) of energy. Similarly, 0.033 kg of CO2 per bottle or 0.033 kg CO2 * 365 * 109= 1.1 x 1010 kg CO2 savings can be realized annually. Proportional multiples of these energy and CO2 savings can be realized for multiple reuses of the same PET bottle. For example, five reuses of a 500mL PET bottle would result in energy worldwide annual savings estimate of 1.82 Exa Joules.