Circular Carbon Blacks Slash Emissions

Cabot Corp. has been named a recipient of the CLEPA Innovation Awards 2024 as a Top Innovator in the Green category for its Replasblak circular black masterbatches. The new Replasblak reUN5285 and Replasblak reUN5290 products are based on mechanically recycled polyethylene and marketed as part of a portfolio with up to 70% ISCC Plus mass balance–certified content.

The Brussels-based European Association of Automotive Suppliers (CLEPA) represents more than 3,000 companies supplying components and innovative technologies for safe, smart, and sustainable mobility.

“We are honored to be recognized by CLEPA for our leadership in advancing sustainable materials innovation. Our universal circular black masterbatches  . . . meet the needs of automotive plastic compounders and converters seeking third-party certified products that incorporate recycled materials and leverage circular value chains,” said Jeff Zhu, executive vice president and president, Carbon & Silica Technologies. “As such, our innovative solutions are transformative, delivering environmental benefits without compromising performance — which are essential factors as the automotive industry continues to progress toward a more sustainable, lower carbon future.”

Zero-carbon carbon black

This development is part of a broad trend in the field of carbon black and other polymer-related products that are increasingly reverting to sustainable raw materials, including those based on end-of-life tire, wood chips, and bamboo. Another innovator in the field of sustainable carbon black solutions is Germany’s carbonauten GmbH, which has developed a low-energy-intensity pyrolysis process for “minus CO₂ factories” designed for the carbonization of various woody residues and problematic materials. The pioneering direct-heat batch retort process reportedly is wear-free and fail-safe. The static slow pyrolysis does not contain any moving parts. This also allows materials containing contaminants such as metals, stones, plastics, and resistant fibers to be carbonized. 

In November 2023, carbonauten GmbH started construction of the world’s largest carbonization plant using its technology in Chibi in the Chinese province of Hubei. Starting in early 2025, around 65,000 tonnes of biocarbons (carbon black), 65,000 tonnes of pyrolysis oils, and 300,000 MWh of thermal, base load-capable, renewable energy will be produced annually from 200,000 tonnes of regional waste bamboo. While carbonauten’s offerings contain a healthy dose of carbon, the company’s slogan has an interesting take on the main root cause of climate change, as evidenced by its corporate slogan, which can be found at this link. (It's not shown here as it uses a four-letter word that some readers might find offensive.)

Carbonauten employees with the prototype bio-compound high-speed-rail seat back, which incorporates 33% biomass-derived carbon black filler. Image courtesy of carbonauten.

Train seat backs are biocarbon black

German rail operator Deutsche Bahn (DB) has worked with carbonauten to develop prototype seat backs and arm rests with 33% biocarbon content, proving that large-format plastic parts with biocarbon can be produced. The biocarbons are derived from wood residue.

Portuguese converter Montemeão carried out several tests with carbonauten’s Tech BioC compound. After the armrests were successfully injection molded in the first trial, the larger seat shells were then fabricated. Carbonauten offers Tech BioC grades based on polypropylene (PP) and acrylonitrile-butadiene-styrene (ABS) polymer matrices.