Understanding the difference between Incinerators and Energy-from-Waste Facilities

What is the difference between an incinerator and an Energy-from-Waste (EfW) facility?

The term “incineration,” which is often erroneously applied to EfW, is an uncontrolled combustion process without energy recovery. Today’s modern EfW facilities are in no way similar to incinerators of the past. Using municipal solid waste (MSW) as the primary fuel source, EfW facilities recover electricity and steam for the communities in which they operate. EfW facilities burn waste in specially designed boilers to ensure complete combustion. The facilities use state-of-the-art pollution control equipment to scrub emissions, preventing them from being released into our environment. The result is energy which is largely renewable. In the US 86 Waste-to-Energy plants supply approximately 2,572 megawatts of generating capacity to the power grid. EfW (also known as Waste-to-Energy) facilities divert approximately 98,000 tonnes of waste from landfills each day, preventing further methane emissions (a greenhouse gas over 20 times more potent than carbon dioxide) from decomposing waste.

What role does waste play in climate change? What will the impact on carbon emissions be?

According to the Intergovernmental Panel on Climate Change (IPCC) approximately 63 percent of global warming is attributable to carbon dioxide (CO₂) emissions, with the majority of CO₂ emissions coming from the burning of fossil fuels for energy generation and transportation.

Methane ranks second to CO₂ in its global warming contribution at 18 percent. Methane is 20 times more potent than CO₂. Landfills are one of the largest sources of methane emissions, which are generated when waste is buried and then decomposes. For this reason the EU has issued a directive to limit the land filling of biodegradable municipal solid waste by 2020 to 35 percent of the quantity generated in 1995.

EfW is a net reducer of greenhouse gas emissions because it eliminates methane from landfills and offsets the need to burn fossil fuel in power plants. In fact, over 50 percent of electricity produced from a Covanta facility can be classed as renewable energy.

EfW technology also has the added advantage over wind and solar power in that it is a ‘continuous’ technology, which is not restricted by weather conditions. The UK intends to produce 30 percent of electricity from renewable sources by 2020 and currently produces around 6.6 percent, according to the most recent figures from the Department of Energy and Climate Change. As a tried and tested method, EfW will enable the UK to reach these ambitious targets by 2020, whilst also sensibly disposing of waste without the need of land fill.

What is left after the waste goes through energy recovery?  Is it harmful? What do you do with it?

After waste is combusted, the products of an EfW facility are energy, Incinerator Bottom Ash (IBA), metals and Flue Gas Treatment Residue (FGTR). Any remaining metals will be mechanically removed and sent to metal processors to be recycled. The IBA will be processed and used as an aggregate in the construction industry: it is suited to use in road sub-bases, saving the need to quarry virgin resources. It is more difficult to recycle FGTR, though it is useful as a treatment for acidic wastes.  The small amounts of remaining FGTR will be delivered to special-purpose landfill for final disposal.

Incinerators were widely known as polluters and dangerous for the environment. What effects do Energy-from-Waste facilities have on our environment?

Emission limits are established by the regulatory authorities to ensure public safety. Covanta operates facilities in both the EU and the US and the limits are very similar. Covanta’s EfW facilities use modern equipment to control combustion and filter the emissions to comply with, and in most cases exceed, the permit requirements. Furthermore, proven test methods and sophisticated monitoring equipment are used to ensure permit compliance.

For the proposed UK facilities, strict reporting requirements will ensure full transparency of facility performance, with emissions monitored by the Environment Agency to ensure that they meet the guidelines laid down by the European Union Waste Incineration Directive (WID).

The UK Health Protection Agency (HPA) has also advised that well run and regulated incinerators do not pose a significant threat to human health, stating the effect is likely to be so small that it would be undetectable.

Avoiding methane emissions from landfills. When waste is delivered to an EfW facility, the methane that would have been generated if it were sent to a landfill is avoided. While some of this methane could be collected and used to generate electricity, a large portion of methane and other harmful pollutants cannot be captured.

Avoiding carbon dioxide (CO₂) emissions from fossil fuel combustion. When a megawatt of electricity is generated by an Energy-from-Waste facility, an increase in carbon dioxide emissions that would have been generated by a fossil-fuel fired power plant is avoided.

Avoiding CO₂ emissions from metals production. In the US, EfW facilities recover more than 630,000 tonnes of metals for recycling annually. Recycling metals saves energy and avoids CO₂ emissions that would have been emitted if virgin materials were mined and new metals were manufactured, such as steel.

Why is there an increasing move towards EfW in the UK?

Recent legislation from the European Union supports a move away from the UK’s reliance on landfill. With an aim to achieve a low carbon and energy efficient country, the UK needs to reach targets set out by EU Heads of State and Government. The following targets are set to be achieved by 2020:

• A reduction in EU greenhouse gas emissions by at least 20 percent from 1990 levels
• 20 percent of EU energy consumption to come from renewable resources
• A 20 percent reduction in primary energy use compared with projected levels, to be achieved by improving energy efficiency.

This legislation encourages a diversion of waste from landfill, imposing heavy fines on countries that do not comply. As a result local authorities in the UK are under increasing pressure to reach strict targets to reduce tonnages to landfill and to explore options for getting the most value from waste.

EfW facilities offer a proven solution for such targets by providing sustainable waste management, maximum diversion from landfill and the generation of renewable energy. This is why ‘Recovery’ is placed above ‘Disposal’ in the Waste Hierarchy, and why the European Union and UK Government both strongly support the use of EfW plants over disposal in landfill.