Experts Discover Better Ways to Break Down and Recycle Plastics 
Wed, April 21, 2021

Experts Discover Better Ways to Break Down and Recycle Plastics 

Plastics are durable, lightweight, and inexpensive materials. They can easily be molded into various kinds of products and applied to almost everything / Photo by: khunaspix via 123RF

 

Plastics are durable, lightweight, and inexpensive materials. They can easily be molded into various kinds of products and applied to almost everything. Because of this, more than 100 million tons of plastics are produced and sold around the world, and around 200 billion pounds of new plastic material is formed and laminated into different packages and products. In the United States, people use 2.5 million plastic bottles that are thrown away every hour. Hence, there is a huge need to recycle plastics in order to manage waste pollution. 

Single-use plastics are one of the leading pollutants in the whole world today simply because they do not easily decompose. Most plastics that people have used today will not decompose for hundreds of years. In Singapore, most plastic waste is incinerated that essentially produces greenhouse gases like carbon dioxide that are then projected into the atmosphere. The leftover material or burn ash is then transported to a landfill that is estimated to be completely filled by 2035. Hence, there is truly a need to find new ways to breakdown plastics in order to be more protective of the environment and also for practical and economical reasons. 

Ways to Recycle Plastic

Plastic recycling is the process of recovering different kinds of plastic materials in order to reprocess them into other different products that are unlike their original form. The most popular ways to process recycling plastic waste is heat compression and monomer. 

Heat compression can recycle different kinds of plastics all at once. It takes in unsorted and cleaned plastic waste and mixed it in massive tumblers. One of the major advantages of this process is that it does not require matching forms of plastic to be recycled all together. It is very popular in the United States, Australia, and Japan.

Meanwhile, the monomer recycling process involves the reversal of polymerization reaction in plastics in order to recycle the same type of condensed polymer together. This process purifies the waste product but it also cleans the plastic waste to create a new kind of polymer. 

According to the Balance of Small Business, a website that publishes smart and innovative news about lifestyle and the sciences, these are the latest advances in plastic recycling. Such technologies include reliable detectors and sophisticated decision and recognition software that improve the productivity and accuracy of automatic sorting of plastics. 

Plastic recycling is the process of recovering different kinds of plastic materials in order to reprocess them into other different products that are unlike their original form / Photo by: Josep Curto via 123RF

 

Turning Plastics Into Useful Chemicals 

Researchers from the Nanyang Technological University in Singapore discovered a new way to turn plastic waste into valuable chemicals by just using sunlight. Their study was published in the Advanced Science journal. 

The research team used mixed plastics with a specific catalyst solvent that allows the solution to harness light energy and convert the dissolved plastics into formic acid, which is a type of chemical used to fuel cells to produce electricity. According to professor Soo Han Sen from the School of Physical and Mathematical Sciences, they made their catalyst from affordable, biocompatible metal vanadium that is usually used in steel alloys for motor vehicles and aluminum alloys for aircraft.

The researchers explained that a vanadium-based catalyst can be easily dissolved in a solution containing a non-biodegradable consumer plastic like polyethylene and by exposing it to artificial sunlight, it can break down the carbon-carbon bonds within the plastic in just six days. This process can turn polyethylene into formic acid, which is essentially a natural preservative and antibacterial agent that can be used for energy generation by power plants and even in hydrogen fuel cell vehicles, as reported on Science Daily, a scientific news publishing website. 

The research team used mixed plastics with a specific catalyst solvent that allows the solution to harness light energy and convert the dissolved plastics into formic acid / Photo by: Pavel Rusak via 123RF

 

Soo added that their team really aimed to develop a sustainable and cost-effective method to harness sunlight in order to manufacture fuels and other chemical products. The new chemical treatment is actually the first reported process that can truly breakdown a non-biodegradable plastic such as polyethylene by just using visible light and a catalyst that does not contain any heavy metal. 

The vanadium-based catalyst that the researchers used to break down plastics came from an organic group that uses light energy to drive a chemical reaction called photocatalyst. This enables the chemical reaction to be powered by sunlight or artificial light, which is new in the industry since most of them use heat that is generated by burning fossil fuels. Moreover, the photocatalyst is low-cost, abundant, and environmentally friendly.

Furthermore, most plastics contain strong chemical bonds called carbon-carbon bonds that are not easily broken down without any application of high heat levels, which makes them non-biodegradable. But the new vanadium-based photocatalyst developed by the NTU researchers are designed to break these strong bonds and it does so by latching onto a nearby chemical group known as the alcohol group and using energy absorbed from sunlight in order to unravel the molecules. 

The team hopes that this can be a new way to recycle and break down plastics and further reduce plastic waste not just in Singapore but around the world. People should also keep in mind that since plastic pollution is causing some serious problems to our environment, the best thing people can do is to either stop their plastic use or at least keep it to a minimum—using the same plastic material over and over again until it just wears out.