Petrochemical companies are using blockchain technology to increase transparency to plastic recycling processes by creating a shared, secure ledger that may contribute to increasing current low recycling rates and promote a circular plastic economy.

Image courtesy of Xresh/Pixabay

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BASF Canada and Dow are separately using blockchain technology to provide reliability to information about a plastic product as it moves through its life cycle.

BASF carried out a test pilot in 2020 in British Columbia for reciChain Canada, a program that “in a nutshell can encourage plastic producers to design plastic products that are more recyclable and allow retailers to prove their products are being handled responsibly at end of life,” said Amy Sandhu, head of sustainability and government relations, BASF Canada.

Blockchain is a digital distributed ledger that allows users to share and store secured and verifiable data, she said by telephone.

Other companies, like Dow, are also using blockchain for recycling purposes. There are also alternative or complementary technologies that aim to help with recycling.

Total global plastic production is about 350 million tonnes per year. Only about 30% of plastic waste is recycled in Europe, 25% in Asia, and as little as 9% in the U.S. 

Markers survive recycling

In the case of reciChain Canada, to track a product a “marker is embedded into the plastic material and it is homogenously dispersed so it can be read, with a scanner and that information is uploaded into the blockchain platform," Sandhu said.

“The marker is also designed to survive the mechanical recycling so even when the plastic material goes through the value chain and goes through the physical recycling process that marker remains traceable,” Sandhu added.

For the initial phase of the reciChain Canada pilot the marker was coded with four data points: the type of plastic, the manufacturer, percentage of recycled content, and the number of times the material has gone through the entire value chain or loop count.

When the information is uploaded, all the members of the value chain can “log in with their user name, and verify that their data is correct,” she said.

The process “allows producers to prove that they are able to track and report on their recycled content targets and their diversion from landfill targets,” Sandhu added.

Tokens as incentives

The intention is to build up an “economic model where a credit or digital token can be generated each time the plastic material moves along the next supply chain actor," Sandhu said.

In that way, "the token or credit is going to increase in value with each additional loop count, so the token will be of greater value on the third loop count than on the second, for example," she said.

This can incentivize producers to design for recyclability as in the future the token can be used to offset EPR fees, she said. 

After British Columbia BASF is exploring expanding reciChain to other provinces in Canada. Alberta is well suited to follow “due to their fast-developing circular economy targets and legislation,” Sandhu said.

Canada has seen initiatives that aim to increase resin producer responsibility as part of efforts to curb down on single-use plastics.

“In Canada we have pretty progressive extensive producer responsibility frameworks (EPR). EPR is a mechanism used to hold producers and retailers accountable for the end of the life of products they are putting out on the market,” Sandhu said.

Physical watermarks

Chemical recycling reduces a polymer to its original monomer form so that it can eventually be processed and remade. Mechanical recycling can involve only reshaping a polymer through heat without going back to the monomer.

There is a very large effort underway in Europe to use physical watermarks to improve recycling. Watermarks, however, cannot survive chemical or mechanical recycling but can help with sorting.

Procter and Gamble said on Feb. 18 that it has been part of this effort since it started in 2015 that runs under the AIM, which the European Brands Association that groups more than 85 companies “from the complete packaging value chain.”

“We are continuing work to establish an industrial market test in order to better understand the full potential for this technology to improve recycling rates in the E.U.,” it said.

Digital watermarks are “imperceptible codes,” the size of a postage stamp, covering the surface of a consumer goods packaging, according to P&G.

Later at recycling centers high-resolution cameras can read the digital watermark, recognize the material, and place it in the appropriate stream.

Dow’s blockchain pilot for mattresses

Dow Polyurethanes, a Dow division, launched on March 18 a blockchain pilot project to test the technology’s suitability “to trace circular polyurethane flexible foam composition and strengthen value-chain transparency.”

ChemChain developed the technology Dow is using to transfer verified product information securely within the Renuva mattress recycling program.

“Ensuring that the necessary compositional information can be shared at every step in the value chain is critical to enable circularity at the end of product life”, said Jihane Ball, Dow’s director of global product safety and compliance.

Dow will use the platform to “generate digital assets containing key encrypted information on the chemical composition” ensuring contents can be identified at every stage of their lifecycle, the statement said.

The company describes ChemChain as a blockchain platform designed for use by the chemical industry to transfer information on chemicals in products along the value chain, from manufacturers to consumers, recyclers, and waste operators.

By Renzo Pipoli