|By using less energy, generating less solid waste and creating significantly fewer greenhouse gases, PET bottles offer a better environmental footprint than aluminum cans or glass bottles. This was the conclusion of a life-cycle inventory of single-serving soda containers. The study was conducted by Franklin Associates for the PET Resin Association (PETRA). It compared total energy, solid waste and greenhouse gas emissions per 100,000 ounces of soft drinks packaged in typical 20-oz PET bottles, 8-oz glass bottles, or 12-oz aluminum cans. In conclusion, PET bottles showed appreciably lower numbers across the board.
Greenhouse gas emissions for the PET bottles were calculated at 1,125 lbs of carbon dioxide equivalents, compared to 2,766 lbs for aluminum and 4,949 lbs for glass. At 59% less than aluminum and 77% less than glass, the lower greenhouse gas emissions for the PET bottles were most notable. Energy use for the PET bottles totaled 11.0 million BTU per 100,000 ounces of soft drink, compared to 16.0 million BTU for aluminum and 26.6 million BTU for glass. Solid wastes for the PET bottles totaled 302 lbs, 767 lbs for aluminum, and 4,457 lbs for glass. Solid waste volume was 0.67 cubic yards for PET, 0.95 cubic yards for aluminum, 2.14 cubic yards for glass.
The life cycle inventory covered extraction of raw materials through container fabrication, as well as post-consumer disposal and recycling. Post-consumer disposal and recycling calculations included transporting to a landfill or incinerator, equipment operations at a landfill, and energy recovered by an incinerator, but excluded incinerator and landfill emissions. Post-fabrication transportation to the filling site, filling, distribution, storage, retail use and consumer use were excluded.
Allied Development Corporation has conducted a comparative life cycle study to calculate green credentials of each packaging type including PET container, glass container, aluminium tins. The study sponsored by Husky Injection Molding Systems concluded that PET containers result into less greenhouse gas (GHG) emissions and used less energy than glass or aluminium cans. It was reported that PET had the lowest GHG emissions at 0.69 KG/1000 unit. The glass container resulted in 1.10KG/1000 unit and the aluminium can had the highest GHG release of 1.26 KG/1000 unit (81% more than PET). This is because the manufacturing process of aluminium from bauxite releases a significant amount of GHG, which contributes to the high level of GHG for aluminium cans. PET bottles also registered the lowest energy consumption at 3,225MJ/1000 units. Glass had the highest energy consumption at 4,227MJ/1000 units � nearly a third more than PET. Aluminium cans used 21% more energy than PET at 3,917MJ/1000 units.