Because society prefers not to think about waste, it has a distorted understanding of waste management. Waste has the logistical characteristics of an ordinary product, but in reverse. The disappearance of large convenient landfill sites adjacent to main centres of population has resulted in waste being transported ever greater distances to cheaper landfill sites often in rural areas.
The saying One man's trash is another man's treasure' is coming true in the waste-to-energy field. Who would have thought that junk and rubbish could be cost-effectively turned into a valuable commodity?
With land becoming ever more valued, landfill overflowing, growing concerns over groundwater and air pollution, and fossil fuel scarcity issues, methods of turning refuse into fuel or electricity are topical and attractive for many reasons.
World energy demand continues to increase. And today, the question is no longer whether to produce more energy but how we can meet the rising demand in the most sustainable and environmentally sound way.
In 2007 the waste to energy services market supported about 200 to 250 companies with Von Roll Inova among the leading players.
The ongoing move away from landfill attracts technological innovation and the current leaning towards waste to energy in many parts of Europe is attracting major capital investment. It is inevitable that further consolidation of the market and investment from a whole range of backgrounds will continue to be drawn to this sustainable growth market.
Wastes represent an increasingly important fuel source.
Using wastes as fuel can have important environmental benefits. It can provide safe and cost-effective disposal options for wastes which could otherwise present significant disposal problems. It can help reduce CO2 emissions through displacement of fossil fuels. Methane is 23 times more damaging than CO2 for global warming. If biodegradable waste is diverted from landfill, methane emissions can be avoided.
Any energy which is recovered from biological wastes can be regarded as renewable energy. It comes from plant material. As plants grow they absorb carbon dioxide from the atmosphere. When this biomass material is used as a fuel, the carbon dioxide is returned to the atmosphere in a carbon neutral' cycle.
If biomass is used to displace fossil fuels instead of being left to decompose naturally, it will actually help to limit the emission of carbon dioxide and methane into the air.
A very wide range of municipal or industrial wastes may be used as fuel. The nature of the waste and the waste disposal method will determine the way that energy can be recovered.
Dry household, commercial or industrial wastes can either be burned (combusted) as raw waste, or they may first undergo some sorting or processing to remove waste components that can be recycled separately.
There are many ways of combining waste disposal with energy recovery. A number of well established technologies are available for generating heat or power from wastes. There are also new technological developments, especially in power generation, which have the potential to increase the efficiency of energy recovery.
The heat recovered from these plants can be used to generate electricity, or can be used for industrial heat applications. The size of the energy from waste plant is designed to meet the waste disposal needs of the community, taking into account the potential for waste minimisation and recycling.
Plants which generate electricity can typically process between 20,000 and 600,000 tonnes per year, and from this they can generate from one to 40 MW of electricity. Power is produced from these wastes by using the steam raised in the combustion process to drive a steam turbine to generate electricity, in a similar manner to a conventional coal fired power station.
Strict environmental standards now apply in all countries governing the emissions from energy from waste plant, particularly of heavy metals, furans and dioxins. All energy from waste plants must now meet these standards, which can be achieved through the installation of extensive state-of-the-art gas cleaning systems. Emissions are demonstrably below any level that would cause any significant impact on public health or on the environment.
Energy from Waste has many benefits. Here are some: EFW reduces the reliance on landfill for waste disposal.
EFW helps local authorities meet government targets.
Waste used to produce electricity reduces the amount of methane and carbon dioxide produced by waste in landfill.
EFW reduces the dependency on fossil fuels to generate electricity.
Using waste to produce electricity displaces carbon dioxide produced by burning fossil fuels.
EFW retrieves metals to recycle.
EFW produces Incinerator Bottom Ash that can be used as a replacement for quarried aggregate in the construction industry.
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