Plastic bottles are transformed into a source of green energy in the USA

An environmental problem since the mass production of plastic materials in the 1950s, so-called microplastics, tiny particles smaller than five millimeters, have spread across our planet.

Extremely durable, taking hundreds of years to decompose, these harmful agents contribute to global warming and contaminate ecosystems with toxic chemicals.

In recent research, published in the journal Angewandte Chemie International Editiona team of researchers proposes use minimal amounts of solvents to break down a specific class of plastics .

“What we did in this research was break down condensation polymers into aromatic compounds that can be used as fuels ”, explains research leader Manish Shetty, professor at Texas A&M University, in the USA, in a press release.

To do this, the team used organic compounds called hydrogen carriers that, in practice, work like sponges to store hydrogen, which is then used to decompose plastic.

How to transform plastic into green hydrogen?

After hydrogen was stored in liquid form using methanol as a carrier, Shetty’s team designed catalysts to use this H2 to transform polyethylene terephthalate (PET) from packaging into the p-xylene molecule, used to produce fuels.

These catalysts accelerate the chemical reactions methanolysis and hydrogenolysis, making them faster, more efficient and more controlled.

In the first of these, methanol helps break down PET into other compounds. In hydrogenolysis, hydrogen (transported by methanol) is used to facilitate the breaking of PET’s chemical bonds.

The research explains how the surfaces of the Cu/ZnZrOₓ catalyst (mixture of copper, zinc and zirconium) use the hydrogen that comes out of organic carriers to transform PET into p-xylene.

Shetty highlights in a statement that by starting with a waste management solution, his research ended up becoming an innovative strategy for the sustainability of the chemical industry .

“These organic molecules transport this hydrogen from where it is generated to where it is used for waste management, especially in an urban environment where we collect a lot of this waste”, concludes the chemical engineer.

Implications of research for reducing fossil fuels

The revolutionary aspect of the research is the dual role reserved for methanol (CH₃OH), an alcohol produced mainly from natural gas.

It is used in the study not only to break PET into smaller fragments (in methanolysis), but also to transport hydrogen in its molecular structure to form p-xylene from PET, in hydrogenolysis.

Using methanol as a source of H2 is advantageous because it eliminates the need to store pure hydrogen, which is challenging due to its low energy density. Furthermore, transporting hydrogen is also an expensive and complex operation.

Excited by the research results, Shetty believes that its application can change the economy, ceasing dependence on fossil fuels.

For him, “one of the things that could happen is that, as hydrogen becomes more available […]we will need hydrogen carriers as a transport vector.”

And, among the uses of these substances that carry hydrogen from one place to another, we would now have “the management and recovery of waste”, says Shetty, transforming them into sources of fuel or other chemicals.

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This content was originally published in Plastic bottles are transformed into a source of green energy in the USA on the CNN Brasil website.

Source: CNN Brasil