BlackCycle claims 'world first' with sustainable carbon blacks

LADOUX, France—The BlackCycle Project, a tire recycling and sustainability initiative, has claimed a world first with the production of what has been described as "sustainable carbon blacks (sCB)."

During a Nov. 22 workshop at Michelin's technology center in Ladoux, the consortium announced the "major leap" towards rubber sustainability with the production of the materials for tire applications using pyrolysis oil derived from end-of-life tires (ELTs).

"This novel production of a sustainable material from end-of-life tires represents a truly circular process," the project stated in a press release.

As part of the project, BlackCycle partners—including tire waste management group Allapur, Orion Engineered Carbons and recycler Pyrum Innovations—joined hands to use pyrolysis oil on an Orion's conventional carbon black furnace reactor.

Orion said it had concluded that replacing fossil fuel-based carbon black with sCB in a rubber compound did not change the properties of the compound.

"Therefore, even the most demanding applications will maintain a high-performance regarding properties such as durability, conductivity, rolling resistance and other characteristics," it added.

Furthermore, the processing of the rubber compounds will be unchanged according to the analysis of the green compounds.

As a result, the consortium expects that the material can be "an easy drop-in solution" without the need to adjust the formulations of the rubber compounds or process parameters, like in mixing, molding or curing.

Commenting on the new technology, industry expert Martin von Wolfersdorff said the collaboration was "nice but had limitations."

"I think there are limits for scaling up, though, as for each ton of sCB, 4 tons of rCB (recycled carbon black) are produced," he said, adding that the yield of pyrolysis oil and furnace carbon black were 50 percent each.

"This means that the current application performance of rCB, which is in the soft blacks range, limits the production of sCB," he added.

In addition, sCB can also be produced from bio-oils (Orion Ecorax Nature grade range), which is the technology that has been used by Pirelli for the 94 percent fossil free concept tire for the Volvo EV.