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0 This article is intended to introduce you to Waste to Energy (WTE) in order to enhance its consideration in waste management strategies and reduce the amount of waste going to landfills.
Waste is part of our everyday lives. The amount of municipal solid waste (MSW) – often referred to as “garbage” or “trash” – generated worldwide has increased tremendously over the years, and it is projected to reach 3.4 billion metric tons by 2050. This will correspond to an almost 70% increase in the amount of waste generated worldwide compared to 2016 levels.
While we all contribute to it, many of us know little about how the waste we generate is managed once it leaves our homes. In an ideal scenario, MSW should be managed using the waste management hierarchy (see image below). This hierarchy implies exploring all waste management opportunities on the higher level before moving down to the next level. The first three levels (Reduce, Reuse, Recycle) are often rightly emphasized and have been previously addressed in one of our webinars. On the other hand, the fourth level, WTE, is often overlooked, as waste which can’t be reduced, reused or recycled is typically sent to the landfill without exploring opportunities to recover the energy in this waste before landfilling. Given this oversight, this article is intended to introduce you to Waste-To-Energy in order to enhance its consideration in waste management strategies and reduce the amount of waste going to landfills.
Source: TEI
What is Waste to Energy?
Waste-To-Energy (WTE) is a term used to describe the recovery of energy from municipal waste. The energy recovered can be in the form of electricity, heat and fuel. While incineration remains the most common process by which energy is recovered from waste, other WTE processes include gasification, pyrolysis, anaerobic digestion, and landfill gas recovery.
Incineration – The Main WTE Process
Incineration is the process by which MSW is burned at high temperatures, and the heat from the fire is used to make steam that is eventually used to generate electricity or heat buildings. The energy produced through this process is considered renewable given that the waste used as fuel is sustainable and non-depletable. Take a virtual tour of the WTE facility in Metro Vancouver to better understand this process.
Burning MSW can reduce the volume of waste going to the landfill by up to 90 percent. This explains why Japan and several European countries which are densely populated with limited open space for landfills adopt WTE practices more than countries with more open spaces such as the United States.
In addition to reducing the volume of waste going to the landfill, Waste-To-Energy by incineration is also considered as a greenhouse gas (GHG) mitigating technology. It avoids the release of greenhouse gases that would have otherwise been generated from burning fossil fuels to produce energy, while also reducing the amount of methane gas produced when waste is landfilled.
Despite these benefits, the installation of incineration facilities to convert waste to energy is often opposed to in several communities due to the fear of air pollution and the release of toxic chemicals in the ash produced from burning waste. To address these fears, modern WTE facilities have incorporated pollution control equipment to prevent the release of emissions into the environment. This has enabled numerous Waste-To-Energy facilities in Canada and the United States to consistently perform better than the required regulatory standards.
Other Waste-to-Energy Processes
Gasification: This a process by which carbon-containing materials are converted into synthesis gas (syngas). The syngas produced can then be burned to produce electricity, or further processed to produce vehicle fuel.
Pyrolysis: This is the thermochemical decomposition of carbon containing materials into liquid fuels. This fuel also called “pyrolysis oil” can be used as a renewable industrial fuel to generate heat and electricity.
Anaerobic digestion: This is a biological process through which organic waste is broken down by bacteria in the absence of oxygen to produce compost and biogas. The energy in the biogas can be burned like natural gas to provide heating and electricity.
Landfill gas recovery: Landfill gas is generated as a by-product of the anaerobic decomposition of organic waste in landfills. This gas, which is made up of methane (the primary component of natural gas), and carbon dioxide (CO2), can be recovered by drilling wells into landfills and using vacuums or blowers to collect the gas. Once collected, landfill gas can be treated and used as a renewable energy resource.
The anticipated tremendous increase in the amount of waste generated forces us to explore alternative ways of managing our waste. Even though Waste-To-Energy lies low in the waste hierarchy, it remains a better option in comparison to diverting waste into landfills. Many people remain unaware of the fact that waste can be used to produce clean and reliable energy, as a result, they turn to landfills without considering Waste-To-Energy. Whereas landfills are an unsustainable use of land and pose risks of water pollution and greenhouse gas emissions.
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Great article Leslie! I learned alot about waste conversion to energy. I think it is a great alternative for countries in the Global South especially where there are higher cases of energy poverty as well as waste in landfills. Did you come across any challenges, opportunities or examples were this is implemented in the Global South?
Thanks Elena.
You are right, Waste-to-Energy could help to address energy poverty and waste management issues in the global South. So far, there is only one incineration WTE plant operating in Africa, and that is in Ethiopia. Some other projects for building WTE incineration plants exist, and some have been forced to stop due to opposition from local communities, such as a project in South Africa.
Some key challenges for incineration in the global South include the high cost of building a WTE incineration plant, lack of waste collection infrastructures, and also the fact that waste in these countries is mainly composed of organic waste that is not the most adequate for incineration. Because of these challenges, I would say WTE by anaerobic digestion is the most suitable for the global South.