ศาสตร์เกษตรดินปุ๋ย : ขอบคุณแหล่งข้อมูล : หนังสือพิมพ์ The Nation
Plastic waste is plaguing our planet. In total, people have produced more than 8 billion tonnes of plastic. Half of all newly manufactured plastic becomes trash in less than a year.
It is projected that in 2050, there will be more plastic in the ocean than fish. PET is one of the most common manufactured plastic polymers (approximately 10-per-cent of total plastics produced per year), is a key ingredient in food and beverage packages and in the fibres of cloth. Historically, most of this material has not been recycled, the primary reason why 8 million metric tons of PET plastics are estimated to go into the ocean each year.
Plastic recycling is collapsing in many parts of the US. Demand for recycled materials has declined because there is too much trash in the sorting mix. As a result, many recycling companies are trying to claw back their profits by raising the cost of their services. In turn, cities like Philadelphia are resorting to incinerating their recyclables for energy, even forcing Memphis International Airport to send its bins straight to landfills. According to the California treasurer, Fiona Ma, “it’s a crisis in the recycling movement right now”.
To help address this problem, IBM recently announced a novel “selective digestion” recycling technique that can significantly streamline the sorting process and turn the PET commonly found in food and beverage packaging into a renewable resource, rather than trash destined for our landfills and waterways.
In the coming years, advancements like VolCat will make plastics recycling more efficient and more versatile in treating a wider range of material types than its predecessors.
Unlike traditional mechanical recycling, future plastics recycling will break down both coloured and clear plastics, as well as dirty and clean containers, producing a high-quality final product that is 100-per-cent recyclable. It should be noted that mechanical recycling can only be used on clear, pre-cleaned containers and results in a material that’s only reusable when combined with new PET.
Plastic bottles, containers, and PET-based fabrics will be collected, ground up and combined with a chemical catalyst in a pressure cooker set to above 200 degrees Celsius.
With heat and a small amount of pressure, the catalyst is able to digest and clean the ground-up plastic, with the process separating contaminants (eg, food residue, glue, dirt, dyes and pigments) from material that is useable for new PET. The useable matter, called a monomer, takes the form of a white powder, which can be fed directly into a polyester reactor to make brand-new plastics.
For people at home, future recycling advancements will mean no more sorting, rinsing and separating used containers, wrappers and plastics. All polyester waste can go directly into the dustbin and out to the curb for collection and from there to a recycling facility, to be digested and transformed into new and renewable material.
If this new research breakthrough is adopted by the plastics and recycling industries, people at the grocery store buying a bottle of soda or punnet of strawberries will know that the plastic they purchased won’t end up in the ocean and in just over 30 years, outweigh the fish.
Patama Chantaruck is vice-president of Indochina Expansion and managing director of IBM Thailand.