Recycling of aluminium laminated pouches and Tetra Pak cartons by molten metal pyrolysis-Pilot-scale experiments and economic analysis

Aluminium laminated (AL) pouch packages and aluminium laminated Tetra-Pak cartons are considered unrecyclable, reducing their otherwise excellent lifecycle performance. This paper describes experimental results on pilot plant trials to recycle AL packages with a molten metal pyrolysis reactor. The experimental evidence shows that both package formats can be recycled and that clean aluminium can be recovered. However, the recovered aluminium from Al pouches may require mechanical cleaning as the consumer's information is printed onto the aluminium, leaving a carbon residue on the recovered aluminium. On the other hand, over 90% of the polypropylene plastic layer on the AL packaging pyrolysed into waxes, pointing to excellent kinetics. Moreover, an economic analysis of a 4,000 t/y commercial-scale plant demonstrates that a molten metal AL recycling plant is economically viable, achieving an internal rate of return (IRR) of over 20%.

Automated summary

This paper presents experimental results on pilot plant trials of recycling aluminium laminated pouches and Tetra-Pak cartons. The study shows that both package formats can be recycled and clean aluminium can be recovered. However, mechanical cleaning may be necessary for recovered aluminium from pouches due to carbon residue. The pyrolysis of the polypropylene plastic layer in the packaging showed excellent kinetics, with over 90% converting into waxes. Economic analysis of a commercial-scale plant demonstrated the viability of a molten metal aluminium recycling plant, achieving an internal rate of return (IRR) of over 20%.