Materials life cycle and recycling – from resource to product, life cycle assessment and reserves
ChemistryApplied & Practical ChemistryAges 14–15
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Sign in to playThree screens on materials and sustainable development: a flow chart from natural resources (crude oil, plant oil, wood, bauxite, sand) through the chemical processes to products (polythene bag, PET bottle, petrol, soap, biodiesel, paper bag, aluminium can, glass bottle); a life cycle assessment comparing plastic and paper bags, PET and glass bottles, and aluminium cans and glass bottles for energy, CO₂, water and solid waste at each stage, with reuse, transport distance and end-of-life options; and a recycling model showing years of reserves left, energy saved and how many times metals, glass, paper and plastic can be recycled.
Lesson: Using Earth’s resources: life cycle assessment and recycling
What it shows
A life cycle assessment (LCA) adds up the environmental impacts of a product at every stage: extracting and processing the raw materials, manufacturing, transport, use and disposal. Comparing products this way can surprise: a paper bag needs more energy and causes more CO₂ to make than a plastic bag, so it must be reused to be the better choice, while a refillable glass bottle beats a single-use PET bottle only if it makes enough trips over short distances. Recycling saves energy and finite resources, most of all for aluminium; metals and glass can be recycled again and again, paper and plastics only a few times.
How to use
Choose a tab. In From resource to product, pick a Resource and a Product to see the processing chain and its chemistry. In Life cycle assessment, choose a Comparison and an Impact, set the Transport distance and Make it lighter, then set Number of uses and End of life for products A and B. In Recycling and reserves, choose a Material and move the Recycling rate and Demand growth sliders.
Parameters you can change
- Mode From resource to product, Life cycle assessment, Recycling and reserves
- Product (processing chain) Poly(ethene) bag, PET bottle, Petrol, Soap, Biodiesel, Paper bag, Aluminium can, Glass bottle
- Comparison Plastic bag and paper bag, PET bottle and glass bottle, Aluminium can and glass bottle
- Impact Energy, CO₂ emissions, Process water, Solid waste
- Starting end of life Landfill, Incineration with energy recovery, Recycling
- Transport distance 0–1000 km
- Material to recycle Aluminium, Steel, Copper, PET plastic, Glass, Paper and card
- Recycling rate 0–95 %
- Demand growth per year 0–4 %
Questions to explore
- How many times must a paper bag be used so that its CO₂ per use is no higher than a single-use plastic bag?
- Why can a refillable glass bottle be the better choice over short distances but not over very long ones?
- Why does recycling aluminium save so much more energy than recycling glass?
