How are beverage cartons recycled?

After beverage cartons have been collected, either from the kerbside or via the bring-bank system, they are taken to a sorting or bulking facility. Here, they are sorted and separated through either manual or automated means to maximise recyclate quality.

If beverage cartons are collected in the same container as other packaging materials, such as plastic, metal and glass, they are separated before being baled and sent for reprocessing at a paper mill. Where beverage cartons are collected with paper, they can either be separated at the sorting facility or recycled as part of a mixed fibre stream, depending on the requirement of the mill.

At the paper mill, baled cartons are dropped into a pulper, similar to a giant domestic food mixer, filled with water and pulped for around 20 minutes. This delaminates the packaging and breaks it down to produce a slurry. The aluminium foil and polyethylene liners are then separated from the wood fibre for recycling into new products or energy recovery.

Beverage cartons collected for recycling in the UK are currently being sent to Sweden, Spain or Italy for reprocessing until a new reprocessing plant for cartons has been established in this country. However, due to the high proportion of renewable energy used in these paper mills, this is still a carbon-efficient way to recycle UK cartons.

Recycling innovation

Stora Enso’s Barcelona mill receives beverage cartons from the UK as well as Spain and other countries, such as France. The award-winning technology at the mill means that Stora Enso is able to recycle all of the materials within the beverage carton. The plastic and aluminium layers are separated from the fibre through a repulping process, enabling both fibre and aluminium to be fully reused and the plastic to be used to generate energy in the mill. The recovered fibre is used for the production of white lined chipboard at the Mill.

How is this achieved? It uses a process called pyrolosis which involves heating up the plastics and aluminium material in the absence of oxygen. This makes the long chains of polyethylene divide into gases and light oils, while the aluminium remains unoxidised and can be recycled and remelted very easily. The process was refined in collaboration with Alucha Recycling Technologies and is the first time pyrolysis has been used to separate plastic and aluminium. Such is the innovation that the new technology was selected as a winner of the 2010 'Best of the Best' LIFE Environment Projects award, granted by the European Union to recognise projects that have a positive impact on the environment.