Deciding between reusing or recycling old technology
Much like the rest of the world, Australia is currently experiencing a recycling crisis and is looking beyond recycling and landfilling processes for waste management options. While waste like paper or organic matter can be composted and other materials like glass, metal and rigid plastics can be recycled, the country is focused on looking to find solutions for non-recyclable plastics other than landfills.
At a meeting last month, federal and state environment ministers endorsed an ambitious target to make all Australian packaging recyclable, compostable or reusable by 2025. One of the proposed processes that was overwhelming supported by environment ministers was the process to turn waste into energy by unlocking the chemical energy stored in plastic waste that will be used to create fuel.
Plastic is made from refined crude oil. Its price and production are dictated by the petrochemical industry and the availability of oil. As oil is a finite natural resource, the most sustainable option would be to reduce crude-oil consumption by recycling the plastic and recovering as much of the raw material as possible.
There are two types of recycling: mechanical and chemical. Mechanical recycling involves sorting, cleaning and shredding plastic to make pellets, which can then be fashioned into other products. This approach works very well if plastic wastes are sorted according to their chemical composition.
Chemical recycling, in contrast, turns the plastic into an energy carrier or feedstock for fuels. There are two different processes by which this can be done: gasification and pyrolysis. Gasification involves heating the waste plastic with air or steam, to produce a valuable industrial gas mixtures called “synthesis gas”, or syngas. This can then be used to produce diesel and petrol, or burned directly in boilers to generate electricity. In pyrolysis, plastic waste is heated in the absence of oxygen, which produces mixture of oil similar to crude oil. This can be further refined into transportation fuels.
Gasification and pyrolysis are completely different processes to simply incinerating the plastic. The main goal of incineration is simply to destroy the waste, thus keeping it out of landfill. The heat released from incineration might be used to produce steam to drive a turbine and generate electricity, but this is only a by-product.
Gasification and pyrolysis can produce electricity or fuels, and provide more flexible ways of storing energy than incineration. They also have much lower emissions of sulfur and nitrogen oxides than incineration.
Through chemical recycling, the plastic would be turned into an energy carrier or feedstock for fuels. There are two different processes by which this can be done: gasification and pyrolysis. Gasification and pyrolysis can produce electricity or fuels, and provide more flexible ways of storing energy than incineration. They also have much lower emissions of sulfur and nitrogen oxides than incineration.
Currently, Australia has invested a serious amount of funding into this research and plans to use the current recycling crisis as an opportunity to explore some innovative ways of turning waste into valuable products. In fact, there are several direct job opportunities in plastic conversion plants, and indirect jobs around installation, maintenance and distribution of energy and fuels.
While the technology to turn plastic waste into usable energy is underway, the country says that they will be doing all that they can to get plastic out of landfills and promote more innovative recycling methods.
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