What is chemical recycling?
Chemical recycling is an alternative and innovative way to recycle plastics. It decomposes polymers into monomers using various processes, such as pyrolysis and gasification. Chemical recycling technologies can treat mixed or contaminated waste that cannot be recycled with existing mechanical solutions. It helps reduce landfills and the leakage of plastic into the environment. Additionally, it limits the use of fossil fuels and the emission of CO2, compared to the incineration of the same waste. It aims to change the way plastics are recycled by attempting to solve the most considerable flaws of mechanical recycling.
How does chemical recycling propose itself as the future?
Chemical recycling introduces itself as a more efficient alternative to traditional, mechanical recycling. Its premise is it can recycle all types of plastics regardless of their resin code, color, and composites. Even the most unrecyclable products such as car tires and old food packaging can be backward-manufactured into crude oil, which will be reused as raw material to create new products.
After the first mechanical steps - such as shredding, separating, and pulverizing- chemical reactors break down waste plastics into their basic components using pyrolysis, to turn them into secondary raw materials, after further distillation of the pyrolysis oil. These materials can then be utilized to make new chemicals and plastics. Several techniques can be used, including:
Dissolution: extracting plastic,
Depolymerization: breaking the material down into its basic building blocks,
Conversion: turning waste into raw materials,
Furthermore, the material goes back to its initial raw state, like liquid hydrocarbon, so it can be decomposed and repurposed an indefinite number of times without losing its quality. That is the end goal of the circular economy: to repurpose waste indefinitely by using it to recreate the raw material needed at the manufacturing stage.
Chemical recycling plants are starting to emerge globally, intending to solve most of these problems innovatively. The main problem for this industry, and the plastic recycling industry in general, is its profitability. Virgin plastic, on a realistic note, will always be cheaper as long as government regulation doesn’t interfere with prices. Time will tell if the current quantity of plastic waste will be attractive to the chemical recycling industry and if it will be profitable in the future, considering the increasing concern for the environmental cause.
Sources:
https://phys.org/news/2020-10-plastic-hydrogen-gas-carbon-nanotubes.html