Toronto, ON
The issue of rapidly filling landfills has been a problem for many First World countries despite the many efforts of aggressive recycling and composting initiatives. It was never a sustainable idea to continue dumping and burning waste as it causes detriments to the environment, as well as to people’s health and safety. There is a need for an alternative, and one such alternative is known as plasma gasification.
What is Plasma Gasification?
Plasma gasification is a waste treatment technology that uses electricity and high temperatures to turn municipal waste into usable by-products without combustion. This treatment includes heating waste to a temperature high enough that it causes the waste molecules to decompose into more simple and safe substances which can be repurposed. It is already found that this form of waste management is more productive and produces a better net benefit than other forms of waste management such as incineration.
Process
Plasma gasification starts with the use of man-made plasma. This is done by passing an electrical discharge through two electrodes, creating an arc between them. The inert gas, which is under high pressure, is then passed through the electric arc into a sealed chamber of waste materials. The interaction between the gas and the electric arc would dissociate the gas into electrons and ions and raise the temperature inside the chamber to temperatures as high as 10,000 ℃ – hotter than the surface of the sun.
As a result, two main by-products are made. Syngas is a mixture of hydrogen and carbon monoxide which are formed from waste materials such as plastic that contain large amounts of hydrogen and carbon monoxide. Once syngas is formed it must undergo chemical treatment in order to remove its contaminants. Cleaned syngas could be burned as fossil fuel and is used to generate electricity which is more than enough to run the gasification plant, any excess energy could be sold off. The other by-product of plasma gasification is known as slag and it is the solid residue that remains. This residue must also be cleaned of its contaminants and after, it could be processed into bricks, or used in metals such as mercury and cadmium.
Potential risks
Plasma gasification seems to be the future for all waste management but it is important to understand some of the costs and risks that come along with this new kind of technology. For example, if the by-products are not properly treated, there may be major environmental consequences. Untreated syngas could emit toxic acids, and untreated slag could still contain toxic elements, creating challenges for solid-waste disposal. Furthermore, environmentalists also worry about if this new form of waste management could potentially make people become more complacent about municipal recycling if the belief that any waste could be recycled becomes widespread.
In the end, plasma gasification presents itself as an enticing alternative to waste management that may save us from the worry of rapidly filling landfills. In fact, this practice and any other alternative type of waste management should be a topic more endowed in today’s society especially since the topic of climate change is so prevalent in day-to-day life.
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