Friday, October 08, 2021

PLASTICS



What If We Pave Plastic Trash Into New Roads? | World Wide Waste

Oct 6, 2021
Business Insider
Presented by BASF

A company in Nairobi wants to install bricks made from plastic trash across Kenya’s capital. Could they become a solution for a country where 90% of roads have never been paved? And are roads made from plastic really a good idea?

Commercially viable production of climate-neutral plastic is possible

Peer-Reviewed Publication

ETH ZURICH

Since the early 1950s, plastics have found their way into almost every area of modern life. Between 1964 and 2014, plastic consumption increased twentyfold, from 15 to 311 million tonnes per year. Not only has environmental pollution from plastic waste increased during this time, but the amount of petroleum its manufacture consumes is large, as are the associated greenhouse gas emissions.

Researchers from ETH Zurich, RWTH Aachen University and the University of California, Santa Barbara have created a new computational model of global plastic production and disposal. The team was led by André Bardow, formerly of RWTH Aachen University and now Professor of Energy and Process Systems Engineering at ETH Zurich. With their model, the scientists demonstrate that it is possible to economically produce plastics that have a net-zero greenhouse gas emissions balance over their entire life cycle.

This is made possible by a clever combination of three technologies that already exist: plastic recycling and plastic production from biomass and from CO2 through carbon capture and utilisation (CCU). The researchers published their study in the latest issue of the journal Science [https://doi.org/10.1126/science.abg9853].

Increased plastic recycling

As the calculations showed, the key is to use as much recycled plastic as possible, supplemented by the other two manufacturing methods. These three types of manufacturing correspond to the principle of the circular economy. By optimally combining the three technologies, the quantity of energy required can be reduced by 34 to 53 percent compared with the current fossil-based manufacturing practice, supplemented with extensive carbon capture and storage (CCS) – particularly in waste incineration plants, where plastic products are burned at the end of their life cycle.

The cost of the newly proposed manufacturing method is on a par with that of this alternative fossil manufacturing scenario. Under favourable conditions, by 2050 the cost of global plastic production can be reduced by as much as 288 billion dollars per year compared to the alternative scenario. To achieve this, biomass, CO2 and renewable electricity must be available at low cost, the extraction and supply of petroleum must become more expensive, and incentives must be provided for investment in recycling. “The lower energy demand may seem counterintuitive, but it results from the amount of energy that recycling saves over the entire life cycle,” ETH Professor Bardow says.

Policymakers can promote the path to climate-neutral plastics by offering incentives for more plastic recycling and increased use of biomass and CCU, the authors conclude in the study. “We shouldn’t think of the different technologies for plastic manufacture individually, because there is great potential in combining them in a clever way,” Bardow says.

This text is a revised version of a press release from RWTH Aachen University.

Effective deconstruction of polyurethane by catalyst based on earth-abundant metal

New manganese-based catalyst shows to be efficient in the recycling of polyurethane (PU), which paves the way for the circular plastic economy for PU.

Peer-Reviewed Publication

AARHUS UNIVERSITY

New method for recycling Polyurethan (PU) 

IMAGE: RESEARCHERS FROM AARHUS UNIVERSITY AND THE REPURPOSE PROJECT DEVELOP AN EFFECTIVE METHOD FOR THE DECONSTRUCTION OF POLYURETHANE BY USING A CATALYST BASED ON MANGANESE, AN EARTH-ABUNDANT METAL. view more 

CREDIT: ILLUSTR.: CHEMSUSCHEM, SEP 12, 2021

Polyurethane (PU) is one of the most versatile thermoset synthetic polymers which through careful choice of monomer and formulation, can be seen in a myriad of different forms ranging from rigid-, flexible and molded foams to adhesives and elastomers just to name a few. Through its many forms, PU is seen in a plethora of different product like shoes, mattresses, and insolation material but also in more sophisticated products like wind turbine blades and components within aircrafts and cars. With a global production estimated to be above 22 million tons, increasing demand and production results in an ever-increasing amount of PU-waste, but here, the lack of good recycling methods means that most PU is send for energy recovery through incineration or is landfilled.

New research by the RePURpose consortium in ChemSusChem spearheaded by Prof Troels Skrydstrup and Ass. Prof. Steffan Kvist Kristensen has now shown that commercial and end-of-life PU-materials can be depolymerized into monomeric building blocks through chemical recycling. Where current PU‑recycling methods generate a secondary PU-material with other characteristics than the original material, this newly developed methodology has the potential to create virgin polymeric material with the same characteristics as the original material.

In the present study, researchers from the Interdisciplinary Nanoscience Center, iNANO, and Department of Chemistry at Aarhus University, reports that a catalytic system based on the earth-abundant base metal manganese, dihydrogen and isopropyl alcohol is effective for deconstructing different PU-materials into a polyol and an amine fraction representing the original monomeric compositions. The authors go to show, that the system can be used on gram scale even at low catalyst loading without diminishing the activity.

In an effort to reduce our plastic footprint and dependency on fossil fuels a change from the current linear model (make-use-dispose) towards a circular plastic economy, where PU is produced, used, recovered and recycled into new PU-materials is needed. The usage of an earth-abundant metal, a green solvent and the potential adaption towards green hydrogen could pave the way towards a circular plastic economy for PU.

For more information go to www.repurpose.nu.

READ ALSO: Newly found way to recycle polyurethane, a ubiquitous though complicated plastic material

CAPTION

The new method for recycling PU is based on a first row transition metal catalyst, a green and cheap base, and a green solvent.

CREDIT

Illustr.: Lise R. L. Pedersen

Read the scientific article in ChemSusChem:

”Evaluation of Manganese Catalysts for the Hydrogenative Deconstruction of Commercial and End-of-Life Polyurethane Samples” by Laurynas GausasBjarke DonslundSteffan Kristensen, and Troels SkrydstrupChemSusChem. 2021.

DOI: 10.1002/cssc.202101705


The research has been carried out by scientists from Interdisciplinary Nanoscience Centre (iNANO) and Department of Chemistry at Aarhus University in collaboration with the RePURpose consortium, incl.  Plixxent A/S, T. Dan-Foam ApS, ECCO SKO A/S, H. J. Hansen Genvindingsindustri A/S, Logstor A/S, N. Tinby A/S, and the Danish Technological Institute. Professor Troels Skrydstrup is in charge of the research team behind the study.

The work was generously supported by the Carlsberg FoundationInnovation Fund Denmark, and the Danish National Research Foundation.


For further information, please contact

Professor Troels Skrydstrup
Interdisciplinary Nanoscience Center (iNANO) & Department of Chemistry
Aarhus University
Denmark
Email: ts@chem.au.dk

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