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With the growing concerns over the use of fossil fuels and how it escalates global warming, countries are now exploring and investing in more renewable energy sources.
One alternative is the waste-to-energy method, which on one hand serves as an alternative to our energy needs while at the same time addressing our growing waste problem.
On the other hand, there are also concerns regarding this technology, such as whether the emission from the waste incineration could instead nullify the benefits that it provided?
What is Waste-to-Energy?
To start with, Waste-to-Energy, also widely recognized by its acronym WtE is the generation of energy in the form of heat or electricity from waste. (The process is also called Energy from waste or EfW). Using developing technology, these various methods aim to compress and dispose of waste while attempting to produce energy at the same time.
Waste-to-Energy plants burn household and similar waste that could not be prevented or recycled. The burning activity from the plants will then generate energy, which can be in the form of steam, electricity, or hot water.
Types of Technologies in Converting Waste-to-Energy
1. Thermal Technologies
- Depolymerization/Hydrous Pyrolysis: A method that employs thermal decomposition wherein the presence of water, the organic compounds are heated at high temperatures.
- Gasification: Converts carbonaceous substances into carbon dioxide, carbon monoxide, and some amount of hydrogen. This process, like incineration, uses high temperatures to obtain results; however, the major difference is that combustion does not occur over it.
- Pyrolysis: Similar to hydrous pyrolysis excluding the use of oxygen. Pyrolysis employs agricultural waste or organic waste from industries.
- Plasma Arc Gasification: A plasma torch is used to ionize the gas and thereafter, help in obtaining synthesis gas. The process generates electricity while compressing the waste
2. Non-Thermal Technologies
- Fermentation: It produces chemical changes in organic substrates through the action of enzymes in the absence of oxygen.
- Anaerobic digestion: Using microorganisms to destroy biodegradable content. Used both domestically and on a commercial level in order to tap the release of energy during the process and utilize it.
Benefits and Potential of Waste-to-Energy
In the context of Europe, Waste-to-Energy Plants can supply 18 million inhabitants with electricity and 15.2 million inhabitants with heat. This is based on 90 million tonnes of remaining household and similar waste that was treated in 2015 in Europe.
The Confederation of European Waste-to-Energy Plants argues that the only option for treating residual waste (dirty, contaminated materials, mixed materials, degraded materials after multiple recycling, and materials containing substances of high concern ) is either landfilling or WtE.
When landfilling is no longer an option, WtE possesses several benefits such as helping to reduce dependence on fossil fuels imports, saves millions of tonnes of CO2, contributes to energy security, and provides sustainable, local, low-carbon, cost-effective, and reliable energy.
The CEWEP also stated that both recycling and WtE are complementary to divert the waste from landfills. Countries like Germany, the Netherlands, Austria, Belgium, Denmark, Sweden, and Finland have introduced landfill bans and includes both recycling and WtE in their waste management system.
Concerns Revolving Around Waste-to-Energy
Despite the benefits that it offers, combustion-based processes for treating waste continues to become a subject of intense debate around the world. This is because, in the absence of effective controls, harmful pollutants may be emitted into the air, land, and water, which may influence human health and the environment itself.
When it comes to human health, the incineration system produces a wide variety of pollutants that are detrimental to human health. Dioxins are the most lethal Persistent Organic Pollutants (POPs), which can affect those living near the incinerator as well as those living in the broader region.
According to the United Nations Environment Programme (UNEP), incinerators are the leading source of dioxin being released into the environment. In addition, a recent study by the EPA identified dioxins as the cause of many cancers.
In terms of economic impact, most of the investments in WtE goes to the control systems to reduce toxic emissions. In the case of developing countries, another problem arises where the average calorific value garbage does not reach the necessary requirement to be used in the incinerators. This makes the process more uneconomical.
Last but not least, building WtE facilities is really expensive. Incineration experts generally state that to have an economically viable operation, it is required to have an incinerator that burns at least 1000 tonnes of garbage each day. The cost to build such a facility is approximately $100 million.
It is clear that Waste to Energy (WtE) alone should not be the only solution to our growing waste problem. Yes, WtE and recycling should be complementary in an integrated waste management system.
Moreover, countries need to stick to the hierarchy of waste management in which waste reduction becomes the top priority, and both landfills and WtE becomes the last option.
As a company that provides responsible waste management solutions, Waste4Change can help companies/organizations who are interested in exploring WtE alternatives by conducting feasibility studies regarding the prospect and compatibility of such waste management solutions.
Our Solid Waste Management Research will try to provide the best solutions and recommendations to possible WtE technology that will leave the least negative impacts. But in the meantime, our best advice is to maximize the implementation of the 3RS Principles.