As flexible laminate packaging becomes ever more popular in food and drink manufacturing, we need to find ways of making it recyclable. Cambridge researchers have developed the first solution for recycling such packaging and retrieving the valuable resources contained within it.

The UK uses 160,000 tonnes of laminates a year for packaging, which means 17,000 tonnes of aluminium end up in landfill. Just imagine if we could routinely recycle this

Dr Carlos Ludlow-Palafox, Enval

Defra is pleased to support this project, which is part of the government’s wider approach to enabling businesses to be more sustainable

Dan Rogerson, former Resource Management Minister

Value from waste

Over the past 15 years, Cambridge researchers have transformed an idea for a novel way of recycling flexible laminate packaging into a commercial process that could divert thousands of tonnes of waste from landfill and recover valuable aluminium.

While great for keeping food and drinks fresh, flexible laminate packaging is hard to recycle. However, the 160,000 tonnes of it used every year in the UK alone contains 17,000 tonnes of aluminium.

The process developed at Cambridge used microwave induced pyrolysis to recover the aluminium. The researchers then set up a new company, Enval Limited, to commercialise their patented technology. Enval built a pilot plant at its R&D centre in Luton to demonstrate the benefits of the process to potential customers. The firm then partnered with food giants Nestle and Kraft to set up the first commercial-scale unit near Huntingdon.

By 2013, Enval had generated new jobs, attracted more than £2m funding from business angels, Cambridge Enterprise and the former local development agency, and is now conducting household recycling trials with three local authorities.

Research, recycle, re-use

Flexible laminate packaging of the kind used for food and drink pouches, pet food packs and toothpaste tubes has been widely adopted by fast-moving consumer goods companies. Its popularity stems from its improved product to pack weight ratio, reduced transport costs and the fact that the aluminium layer in the laminate protects the contents from oxygen, moisture and light.

The UK alone uses more than 160,000 tonnes of flexible laminate packaging each year, containing more than 17,000 tonnes of aluminium. Until now, however, this kind of packaging has been impossible to recycle. As a result, the packaging ends up in landfill and the valuable aluminium is lost.

With a recycling solution, however, flexible laminate packaging is a highly sustainable packaging solution as well as a substantial commercial opportunity, with potential revenue of approximately £200 million a year in Europe from the sale of aluminium alone.

In addition, the food industry wants to be able to market its aluminium laminate packaging as ‘recyclable’ and recycled aluminium is valued as being environmentally friendly – as producing secondary aluminium via recycling uses 95% less energy compared with producing primary aluminium from bauxite.

Microwave solution

Professor Howard Chase and Dr Carlos Ludlow-Palafox in the Department of Chemical Engineering and Biotechnology began research on a novel process for recovering valuable aluminium plus hydrocarbon liquids and gases from waste laminate packaging in 1999.

With an EPRSC grant, they established the viability of using microwave induced pyrolysis. The new process involves pyrolysis of the waste in a stirred bed of carbon particles heated by microwave radiation.

As well as being cleaner than incinerating the waste, which produces greenhouse gases and toxic emissions, using the new process means the valuable aluminium in the packaging can be recovered and the residue can be ‘cracked’ to produce hydrocarbons for feedstock recycling.

The fragile aluminium foil remains undamaged and can be extracted clean and ready to be reintroduced into the aluminium supply chain. Life cycle analysis shows that the aluminium obtained via this process has a carbon footprint 72% lower than that of primary aluminium. Together with Dr Alex Domin, they founded Enval in 2006 to commercialise the patented technology, prototype equipment and study both the operating parameters and the nature of the hydrocarbon products.

They then used this knowledge to build first a pilot plant and then a commercial-scale demonstration unit, and are now working with local authorities to trial the inclusion of flexible laminate packaging in existing household recycling schemes.