Life-cycle assessments
A A 'cradle-to-grave' analysis of the impact of a manufactured product on the environment. Also known as a life-cycle analysis. or LCA is a 'cradle to grave' analysis of the impact of a manufactured product on the The immediate surroundings in which people live, or the natural world such as the land, air or water.. The main stages are:
- obtaining the Basic material that goods are made from such as crops, metals, wood and animal products such as wool and leather. needed
- manufacturing the product
- using the product
- disposing of the product at the end of its useful life
The four main stages
At all stages, an LCA is likely to include information about the use of The capacity of a system to do work or the quantity required for mechanical work to take place. Measured in joules (J). For example, a man transfers 100 J of energy when moving a wheelbarrow., transport of materials, and the release of waste substances into the environment.
1. Raw materials
All the raw materials we need come from the Earth's The outer layer of the Earth on top of the mantle., The layers of gases that surround the Earth. The important gases in the atmosphere are nitrogen, oxygen and carbon dioxide. or oceans, or are due to living organisms. Obtaining these materials has an impact on the environment, including:
- using up A resource that is no longer being made or which is made extremely slowly, such as crude oil and metal ores. such as A rock containing enough quantities of a mineral for extraction to be possible. and Mixture of hydrocarbons, mainly alkanes, formed over millions of years from the remains of ancient dead marine organisms.
- damaging A place where plants, animals and microorganisms live. through The removal of rocks from the land., When natural resources are extracted from the ground., or felling trees
2. Manufacture
The manufacture of products has an impact on the environment, including:
- using up land for factories
- the use of machines and people
3. Use
The impact of a product on the environment during its use depends on the type of product. For example, a wooden chair has very little impact, unless it needs cleaning or repair. On the other hand, a car will have a significant impact.
4. Disposal
The disposal of old products has an impact on the environment, including:
- using up land for Places where refuse is buried underground.
- whether any or all of the product can be Used materials that have been reprocessed to make new materials. or reused
Question
The table shows some data about the energy needed in the life cycle of a pillow case.
| Life cycle stage | Energy use |
| Raw materials | 10% |
| Manufacture | 15% |
| Use | 70% |
| Disposal | 5% |
| Life cycle stage | Raw materials |
|---|---|
| Energy use | 10% |
| Life cycle stage | Manufacture |
|---|---|
| Energy use | 15% |
| Life cycle stage | Use |
|---|---|
| Energy use | 70% |
| Life cycle stage | Disposal |
|---|---|
| Energy use | 5% |
Discuss the use of energy during the life cycle of the pillowcase, and describe one way in which the energy use could be significantly reduced.
15% of the energy use is associated with making the pillowcase, and very little in disposing of it. The greatest use of energy happens when it is being used, probably because of washing, drying and ironing the pillowcase. Energy use could be reduced by drying it outside and without ironing it.
