The Waste Problem
Waste is a significant global issue. Increasing volumes of waste are being generated as the global population and living standards rise.
The environmental impact is significant, with massive volumes of waste generated annually with only basic or little treatment to minimise its impact. People are increasingly concerned about the production of waste and its effect, and are seeking ways to deal with the problem. They are also asking governments to take steps to minimise the environmental impact of waste.
While recycling and other basic methods to treat waste have been introduced, the conversion of waste back to its constituent parts is still in its infancy.
Rubber presents a significant waste issue. As tyres are built to last they are not naturally degradable or easy to treat once disposed of. The number of tyres discarded globally is estimated at more than 1.5 billion.
In Australia, approximately 51 million tyres reach the end of their life each year. Of these, only around 5% are recycled locally, around 32% are exported for recycling and energy recovery, and the rest are either landfilled, stockpiled, illegally dumped or “lost”.
If end of life tyres are not managed properly they create economic, health and environmental issues, including:
- Taking up valuable landfill space.
- Fires in tyre stockpiles are almost impossible to extinguish and they release toxic gases and chemicals.
- They can trap methane gases, causing them to become buoyant, or bubble to the surface. This ‘bubbling’ effect can damage landfill liners that have been installed to help keep landfill contaminants from polluting local surface and ground water.
- Providing breeding grounds for mosquitoes and other vermin. Bales of whole tyres hold water and therefore provide incubation for mosquitos and the diseases they carry.
- The cost of monitoring and removal.
Globally, the problem is even more acute, with more than half of end of life tyres burnt for fuel, causing the emission of hazardous and poisonous gasses.
Timber has historically been treated with a range of chemicals to protect it from insects such as borers and termites, and to minimise rot and decay.
However, these pesticides can be harmful to people and the environment, leading to significant issues with the timber once it reaches its end of life.
Much timber used in houses including joinery and fencing has been treated with these hazardous chemicals and conversion technology may be useful in reclaiming and reusing the component parts. Timber can be treated to safely remove toxicity and significantly reduce volumes of waste going to landfill.
Contaminated soils are an increasing issue, both from an environmental and land use perspective.
Soils can be contaminated with a range of undesirable chemicals due to various causes including past industrial activity, agricultural chemicals or improper disposal of waste.
Clean conversion technology may be applicable to treating contaminated soils, particularly where the processing unit can be easily transported to the effected site.
While plastics have been the focus of most recycling efforts in recent years, there remain a number of issues. Some types of plastic are not easily recyclable, and recycling programs still lead to high levels of waste due to the mixing of different plastics.
Conversion technology may provide a solution for some plastics by converting them cleanly back into their component parts, which are predominantly hydrocarbons.