Hundreds of millions of tons of plastic are produced each year. Most of them become waste and will decompose over centuries, thereby creating global environmental problems. Therefore, scientists have turned their attention to finding ways to convert plastic into energy, including liquid fuel suitable for engines and industrial uses. And they found him. Read more in the Rambler article.
Pyrolysis: the main method of converting plastics
The technology in focus today is called pyrolysis. The process involves heating plastic waste to high temperatures in the absence of oxygen, causing long polymer molecules to break down into shorter hydrocarbon chains – liquid, gas and solid parts.
Pyrolysis is not new; it has been studied for decades. In its standard form, it produces a mixture of products that can then be processed into gasoline, diesel or fuel oil. However, classical pyrolysis plants often require catalysts (chemical reaction accelerators) to increase fuel efficiency and improve quality, which increases the cost and complexity of the process.
Recent scientific advances
One of the key recent advances came from the work of scientists at Yale University, who developed a pyrolysis plant that does not use expensive catalysts. According to Yale EngineeringUsing a 3D printed reactor with a porous structure, they were able to convert about 66% of the plastic into chemically useful components suitable for fuel.
In this system, the reactor design itself plays an important role. It is divided into three zones with different pore sizes, allowing the plastic to decompose step by step. Large pieces of material are first broken down into smaller compounds and then into simple hydrocarbons. This approach reduces the formation of byproducts and makes the process more manageable. Thanks to this, the plastic decomposition process occurs due to the temperature and shape of the reactor without the use of chemical catalysts, which often complicates and increases the cost of the technology.
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It is worth noting that not all plastics are easily converted into fuel. Polyethylene (PE), polypropylene (PP) and polystyrene (PS) are considered the most suitable due to their chemical structure.
Examples of active projects
Pyrolysis technology has been used not only in laboratories. For example, a startup in Mexico Petgas Using a pyrolysis plant to process plastic waste into gasoline, diesel fuel, kerosene and paraffin. His device heats plastic without oxygen, initially using propane gas to start the process, then sustaining the energy from the released gas.
Such a plant is capable of processing approximately 1.5 tons of plastic per week, generating more than 350 gallons of fuel (≈1350 liters). However, according to the company, carbon dioxide emissions are lower than with traditional fuels – although this still does not make the process completely clean in terms of carbon emissions.
Larger industrial projects are also gradually being implemented: in the Congolese city of Kinshasa, a plastic thermal power plant is planned that will process hundreds of tons of plastic waste every day and generate electricity, diesel fuel and industrial lubricants.
Technical, economic and environmental issues
While the idea is appealing, turning plastic into fuel has both economic and environmental limitations.
- Energy consumption. Pyrolysis requires high temperatures – hundreds of degrees Celsius – making the process consume a lot of energy. Using electricity for heating can increase your carbon footprint if the energy is not from a renewable source.
- Emissions and fuel quality. Liquid pyrolysis products do not always meet gasoline and diesel engine standards without further refining and processing. Some pyrolysis methods use catalysts or an additional cracking step is necessary to produce fuel of required quality.
- Continued dependence on fossil sources. Widespread adoption of such technologies can only delay the transition away from fossil fuels and encourage continued plastic production rather than reduced plastic consumption.
Today, technology to turn plastic into fuel is still only a temporary solution. They can reduce the burden on landfills and partially reduce the dependence on virgin hydrocarbons, but such methods do not eliminate the main problem – the continuous increase in plastic production and their accumulation in the environment. Therefore, from an environmental point of view, this is only a temporary way to deal with the consequences of the existing system.
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