What is Waste To Energy?

Waste to energy is facilities or plants that burn municipal solid waste (MSW) – trash or garbage. Waste-to-energy plants burn waste to produce steam in a boiler and then use it to generate electricity.

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Municipal solid waste is filled with energy-rich materials that are thrown away, such as plastics, yard waste, paper, and products made from wood. Approximately 85 pounds of waste is burned as fuel to produce electricity for every 100 pounds of waste in the United States. Waste to energy plants can reduce 2,000 pounds of waste to ash- weighing around 300 to 600 pounds, reducing the volume of waste by 87 percent.

There are several types of waste-to-energy methods and technologies. Waste to-energy method mostly used in the United States is the mass-burn system. This system burns unprocessed garbage in a large incinerator with a boiler and a generator to produce electricity. Another waste-to-energy method includes processing waste to remove the incombustible materials for them, generating refuse-derived fuel. This method is not widely used.

There are seven stages in a waste-to-energy plant to produce electricity. They are as follows:

• Garbage is collected and then dumped from garbage trucks in a large pit.
• The garbage is carried by a crane and put in a combustion chamber.
• Garbage is burnt, and it releases heat.
• The heat converts water into steam in a boiler.
• Further, the pressure of the steam turns the blades of a turbine generator to produce electricity.
• Due to pollutants in the combustion gas, an air pollution control system is installed to remove the pollutants before it gets released through a smoke stack.
• Ash is collected from the air pollution system and the boiler.

Generally, there are two ways for un-diverted garbage- incinerator or landfill. Both of these options are not ideal. Thus, during the 19^th century, there were attempts to explore new ways to dispose of waste or improve the existing situation. Experts in Europe saw an opportunity to recover energy from several waste products. Instead of burning waste to get rid of it, it was found that the incinerators’ heat could help power turbines. Thus, waste-to-energy came into being.

Years later, the same methods given above are still important in the ‘waste to energy’ concept. However, as the world begins to seek cleaner energy and more efficient and sustainable waste management, problems with waste-to-energy have begun to outweigh the benefits.

Pros of Waste-To-Energy

Waste to-energy developed for a reason. Unlike conventional waste management methods, it clearly has several benefits. For example, it reduces the waste in landfills, the use of an otherwise wasted resource, and the chance to recover resources.

1. Better Than Traditional Waste Disposal Methods

Waste-to-energy is often called ‘clean energy’ when compared to previous decades’ traditional incineration and other wasteful disposal practices. Waste to energy uses the energy that would otherwise be discarded incorrectly.

2. Avoiding Waste in Landfills

Landfills are the last resort when it comes to disposing of waste. It causes severe environmental hazards like air pollution, water pollution, and an increase in greenhouse gas emissions. According to 2018 data from the Environmental Protection Agency, about 146 million tons of municipal solid waste was disposed of in landfills- that’s about 50 percent of all MSW.

Waste to energy methods significantly reduces the amount of waste that usually goes into landfills. Waste to energy facilities can reduce the amount of waste by approximately 87 percent.

3. Recovery of Resources

Waste-to-energy allows for the recovery of valuable resources, such as metals, before it is incinerated. These resources can be sent to recycling centers and thus can be kept in the economy. In landfills, recyclable materials like metals are burnt when they can be used for other purposes. Incineration burns materials such as plastics, paper, etc., but leaves the metal behind.

Cons of Waste-To-Energy

Even though waste-to-energy is much better than traditional waste management systems, it still has several disadvantages. And its disadvantages have grown even more during the past couple of years, such as the particulates and pollution it produces, the destruction of valuable materials, and the potential to disincentivize renewable energy sources and sustainable waste management solutions.

1. Greater Emissions

Nearly all the carbon content in the garbage burnt for waste-to-energy is emitted as carbon dioxide- one of the most common and significant greenhouse gases. If waste fuel is biomass- of natural origins like paper and paper board, natural cloths like cotton, wood, and food waste- then the carbon dioxide it contains was originally taken from the air.

Plastics, oil-based products, and other materials that are also burnt in waste-to-energy are equal to any other fossil fuel and lead to dangerous greenhouse gas emissions.

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2. Recoverable Materials Destroyed

Even though the waste-to-energy system enables the recovery of valuable resources such as metals, in reality, it destroys even more resources. Waste-to-energy incineration usually happens through a process known as ‘mass-burn’ in the United States. In this process, all kinds of the waste get burnt without separating it. Waste to energy processes can also destroy resources that could be recovered, such as metals, minerals, etc.

3. Disincentivize Recycling

Waste-to-energy has the potential to disincentivize recycling and other sustainable waste management systems. Suppose companies, individuals, governments, and organizations believe that waste-to-energy is a sustainable waste management method. In that case, they are less likely to invest in recycling, reusing, and reduction solutions.

4. Unregulated Waste Trade

Development countries usually send their waste to developing countries for processing to improve recycling rates. Only a small amount of waste is recycled, while the rest is incinerated or used in waste-to-energy plants. This unregulated waste trade mostly leads to improper disposal and several environmental hazards.