From recycling to upcycling: A smarter way of dealing with plastic


Date:
September 29, 2021
Source:
RMIT University
Summary:
Researchers have developed a clean and cost-effective way to
upcycle used plastic, transforming it into valuable nanomaterials
and high-quality fuel.



FULL STORY ========================================================================== Researchers have developed a clean and cost-effective way to upcycle used plastic, transforming it into valuable nanomaterials and high-quality
fuel.


==========================================================================
Key points
* New tech produces carbon nanotubes and clean liquid fuel from used
plastic
* Smart solution for upcycling plastic and agricultural waste
simultaneously
* Circular economy approach to help turn two massive waste streams
into
genuine revenue
Globally only about 20% of waste plastics are recycled. Boosting that
figure remains a challenge as recycling plastic cleanly can be expensive
and usually produces lower-value products, often making it financially unviable.

The new method from researchers at RMIT University in Melbourne,
Australia, can produce high-value products from plastic -- carbon
nanotubes and clean liquid fuel -- while simultaneously upcycling
agricultural and organic waste.

The team's two-step process, revealed in the Journal of Environmental Management, converts organic waste into a carbon-rich and high-value
form of charcoal, then uses this as a catalyst to upcycle the plastic.

Lead researcher Associate Professor Kalpit Shah said upcycling two
massive waste streams through one circular economy approach could deliver significant financial and environmental benefits.



==========================================================================
"Our method is clean, cost-effective and readily scaleable," Shah said.

"It's a smart solution for transforming both used plastic and organic
waste - - whether tonnes of biomass from a farm or food waste and garden clippings from household green bins.

"We hope this technology could be used in future by local councils
and municipal governments to help turn this waste into genuine revenue streams." High-value nanomaterials The new plastic upcycling approach
offers a sustainable alternative for the production of carbon nanotubes
(CNTs).



========================================================================== These hollow, cylindrical structures have exceptional electronic and
mechanical properties, with applications across a broad range of sectors including hydrogen storage, composite materials, electronics, fuel cells
and biomedical technologies.

Carbon nanotubes are in growing demand, particularly in aerospace and
defence, where they can facilitate the design of lightweight parts. The
global market for CNTs has been projected to reach $5.8 billion by 2027.

Turning old into new The new method starts with converting agricultural
or organic waste to biochar -- a carbon-rich form of charcoal often used
for improving soil health.

The biochar is used to eliminate toxic contaminants -- such as Poly-cyclic Aromatic Hydrocarbons, known as PAHs -- as the waste plastic is broken
down into its components of gas and oil.

The process eliminates those contaminants and convert plastics into high- quality liquid fuel.

At the same time, the carbon in the plastic is converted into carbon
nanotubes, which coat the biochar.

These nanotubes can be exfoliated for use by various industries or the
nano- enhanced biochar can be used directly for environmental remediation
and boosting agricultural soils.

The study is the first to use low-cost and widely available biochar as
a catalyst for making contaminant-free fuel and carbon nanomaterials
from plastic.

Shah, the Deputy Director (Academic) of the ARC Training Centre for Transformation of Australia's Biosolids Resource at RMIT, said while
the study only investigated one type of plastic the approach would be applicable to a range of plastic types.

"We focused on polypropylene as this is widely used in the packaging
industry," he said.

"While we need to do further research to test different plastics, as the quality of the fuel produced will vary, the method we've developed is
generally suitable for upcycling any polymers -- the base ingredients for
all plastic." Hyper-efficient reactor The experimental study conducted
at lab scale can also be replicated in a new type of hyper-efficient
reactor that has been developed and patented by RMIT.

The reactor is based on fluidised bed technology and offers significant improvement in heat and mass transfer, to reduce overall capital and
operating costs.

The next steps for the upcycling research will involve detailed computer modelling to optimise the methodology, followed by pilot trials in
the reactor.

The team from RMIT's School of Engineering is keen to collaborate with
plastic and waste industries to further the research and investigate
other potential applications of the upcycling method.

The research was supported through an Australian Research Council DECRA Fellowship.

========================================================================== Story Source: Materials provided by RMIT_University. Original written
by Gosia Kaszubska.

Note: Content may be edited for style and length.


========================================================================== Journal Reference:
1. Kalpit Shah, Savankumar Patel, Pobitra Halder, Sazal Kundu, Mojtaba
Hedayati Marzbali, Ibrahim Gbolahan Hakeem, Biplob Kumar
Pramanik, Ken Chiang, Tejas Patel. Conversion of pyrolytic
non-condensable gases from polypropylene co-polymer into
bamboo-type carbon nanotubes and high- quality oil using biochar
as catalyst. Journal of Environmental Management, 2022; 301:
113791 DOI: 10.1016/j.jenvman.2021.113791 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/09/210929094218.htm

--- up 3 weeks, 6 days, 8 hours, 25 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1:317/3)