Plastic remains the modern world’s packaging material of choice. Roughly a third of the 350 Mt produced globally is used in packaging applications. But as public perception shifts and the issue gets pushed up the political agenda, the tide could be turning. The humble single-use plastic water bottle has become a powerful symbol at the heart of the debate. Bottles used for beverages like water and soft drinks are typically made from polyethylene terephthalate (PET). And according to a European Commission study, PET bottles and their lids are some of the most commonly found items among ocean debris.
PET bottle consumption is increasing. As shown in our report on the EU’s single use plastic directive, in Europe it’s now around 140 units per person, per year. In the US it’s 290 units. Globally, around 57% of these are collected, according to the latest figures from our RPET Global Supply Demand Analytics Service. Political pressure will see that figure rise. One of the most ambitious targets of the EU directive is the call for 90% of PET beverage bottles to be collected by 2029. Significant investment in new waste management infrastructure is needed to meet this goal.
But collection doesn’t guarantee recycling. In the US, 70% of the plastic collected for recycling goes to landfill. It’s 30% in the EU. Many argue that the real mission is to find a cleaner, greener alternative. Aluminium is one contender. Coca-Cola Co.’s Dasani water brand, for example, will soon be available in cans in the US as part of its efforts to reduce plastic waste. So, how does a can compare to a plastic bottle?
On a first-use basis, neither material scores highly. Plastics rely on crude oil extraction. It’s an energy-intensive process, from drilling and refining to extrusion and moulding. A 2017 life cycle assessment study on PET resin from the CPME showed that producing virgin material requires 69.6 GJ/tonne.
Aluminium is extracted and refined from mined bauxite ore. It’s complicated, costly and energy-intensive. We calculate that it takes an average of 14,000 kWh of electricity to produce one tonne of aluminium. Life cycle assessment studies from the Aluminum Association indicate that the total primary demand for aluminium production is 138 GJ/tonne. Electrolysis accounts for the majority of the total primary energy requirements and it has also been shown that 36% (depending on location and value chain) of this energy demand can be sourced from renewable sources, often hydro.
In terms of temperatures, polymer can be produced and extruded at around 250-300°C. Aluminium smelting requires temperatures over 1,000 °C. PET has the highest recycling levels of any of the six most common resins used in packaging. By 2029, we forecast that 68% of PET bottles will be collected globally . There will be some disparity in regional collection rates, however: 30% in the US, 57% in Europe and 82% in China.