Substituting Oil-Based Products
- Sustainability refers to the use of resources in such a way that the requirements of the current generation are met without depleting these resources for future generations
- This requires the use of renewable resources - which can be used without the resource running out
- An example would be solar energy - it will not run out in our lifetime as the sun will continue to shine every day for several billion more years
- Fossil fuels are an example of a non-renewable resource, as they could potentially run out if we use them too fast (since it takes millions of years for fossil fuels to form)
- Sustainable practices are those that minimise the damage done to the environment and its resources, to ensure that there will be something left for the next generation
- An example would be replanting trees after logging
- Unsustainable practices are limited by a finite supply of resources
- An example is the use of fossil fuels to make oil-based plastics
Plant fibres and sustainability
- Using plant fibres to make products such as ropes and fabric is more sustainable than using oil-based plastics
- Less fossil fuels are used and plants can be replanted for the next generation
- Plant fibres are biodegradable, unlike most oil-based plastics, which means the products made from these fibres can be broken down by microbes to minimise environmental pollution
- Extracting and processing oil is an expensive and difficult procedure compared to growing and processing plants, making plant-based products easier and cheaper to produce in developing countries
- However, the ropes made from plant fibres are typically not as strong as plastic ones
Starch and sustainability
- Plants store excess sugars as starch in their cells
- Starch can be used to make bioplastics which is more sustainable than making oil-based plastics
- It does not require as much fossil fuels to be burned to produce them and the crop plants can be replanted (renewable resource)
- Starch can also be used to make bioethanol, which can be used as a fuel for vehicles
- Using starch to produce biofuels is more sustainable than producing them from oil
Bioplastics
- Bioplastics are made from biological polymers e.g. starch and cellulose
- There are multiple benefits to using bioplastics as a suitable replacement of traditional plastics
- Sustainability: starch and cellulose are plant based materials which can be replaced at a sustainable rate; unlike oil based plastics which are made from non-renewable fossil fuels
- Biodegradable: since bioplastics are made from biological material, it can be broken down by microorganisms; unlike oil based plastics which is generally not biodegradable
- This could potentially decrease the amount of plastic pollution that is currently having a detrimental effect on the environment
- Currently, there are several different types of bioplastics in use
- Cellulose-based plasticsĀ are made from wood pulp and are mainly used as food wrappers (e.g. cellophane)
- Thermoplastic starch which is a mixture of starch and other compounds, such as gelatine, to create a smooth and shiny plastic
- This has been used with great success in the pharmaceutical industry to create easy to swallow capsules that contain drugs
- Polylactic acid (PLA) produced from maize or sugar cane and have properties similar to polyethene
- Poly-3-hydroxybutyrate (PHB) which is made from products of the sugar industry and used in ropes, bank notes and car parts
- Bioplastics can be burned once they are no longer used to avoid the production of methane during decomposition
- Methane is a much more potent greenhouse gas than the carbon dioxide released during combustion
- An added advantage to burning is that the energy released can be utilised to generate electricity and produce more bioplastics
- There are several challenges concerning the use of bioplastic
- They do not always have the same useful properties as oil based plastics
- Bioplastics are more expensive than oil based plastics
- Using limited food crops to produce plastics (which do not feed the hungry) is a controversial subject in some parts of the world
