Evaluation of energy and CO ₂ emissions in soft drink containers: PET versus Glass

ABSTRACT

The present paper aims to assess and compare which material (PET or glass) provides a more sustainable life cycle for soft drink containers. Four glass containers, three returnable ones and one disposable were compared to five PET containers (polyethylene terephthalate), three disposable ones made from virgin material, one disposable made from 20% of recycled material and one returnable (RefPet). The CES-Selector/EcoAudit program, which considers five main stages of the product life cycle - material (obtaining raw material), production, transportation, use and disposal - , was used. The resulting indicators were the energy and the amount of CO² emission. The results, for every 1,000 liters of soft drink bottled, prove that the reuse of containers is the most environmentally correct choice and show that in PET bottles the larger the container capacity the smaller the amount of PET material used, lower the energy and the lower the CO² emission. On the other hand, for glass bottles, the result is opposite, that is, the larger the container capacity, the greater the amount of material used, the greater the embodied energy and the greater the CO² emission. Considering the incorporated energy and the CO² generated, the final result shows that glass containers present better results when filling small-volume packages (290 ml glass and 250 ml PET), while PET containers are the most suitable ones for larger volumes (above 600 ml).

Keywords:
energy; CO² emission; EcoAudit; polyethylene terephthalate; glass