HERO BANNER - ROYCE COLOURS3

Sustainable Replacements for Coal Tar Pitch Binders used in the Foundation Industries

Case Study

Home / Impact / Sustainable Replacements for Coal Tar Pitch Binders used in the Foundation Industries

In collaboration with Morgan advanced materials, this ICP-Royce funded project, awarded £116,025 has allowed for the exploration of the use of wood tar biopitch (WTB) as a sustainable replacement for coal tar pitch (CTP), a ‘sunset’ material under REACH guidelines.

CTP is a residue formed from the distillation of coal tar and is widely used as a carbonisable/graphitisable binder for many industrial applications. CTP, though, is fossil-derived and toxic, and has recently been classified as a ‘sunset’ status material under REACH. In addition, increasing environmental regulations are currently raising concerns about its long-term availability and supply. Thus, it is vital to identify sustainable alternatives that can replace CTP.

During this project, we produced Wood Tar Biopitch (WTB) from distilling sawdust, mixed it with graphite particles and then carbonising and graphitizing them to produce carbon-carbon composites. We investigated the improvement of their microstructure and levels of graphitization during carbonisation/graphitization by refining the composites’ chemical formulations, which led to improved electrical and mechanical properties.   

The Henry Royce Institute was the only place worldwide where meaningful results could be delivered in such a short time, since it builds upon the unique combination of people, equipment and academic-Morgan collaboration. Royce facilities such as electron microscopy, microCT, tribology testing, custom spark tester, and Raman spectrometers were essential in understanding the WTB production, formulation, pyrolysis and resultant properties. This project has helped accelerate the replacement of a sunset fossil derived chemical with a bioderived chemical with reduced toxicity, contributing towards a UK sustainable net-zero future by 2050. It has aided UK industry in this transition through both providing a deeper understanding of the underlying materials chemistry of WTB and establishing a Royce-based WTB source.   

“This project has helped accelerate the replacement of a sunset fossil derived chemical (Coal Tar Pitch), which is used throughout the foundation industries as a carbonisable/graphitizable binder, with a bioderived chemical with reduced toxicity (Wood Tar Biopitch) through both providing a deeper understanding of the underlying materials chemistry of WTB and establishing a WTB source, making strong contribution towards a UK sustainable net-zero future by 2050.”

DR CRISTINA VALLES
Department of Materials, National Graphene Institute and Henry Royce Institute (University of Manchester), Morgan Advanced Materials research fellow.

Collaborators

Morgan was founded in 1856 in London and has grown into a FTSE250 company with £1.050 Bn turnover, headquartered in Windsor. In addition to Morgan being a foundation company, it supports a wide cross-section of the foundation sector with its key products grouped into molten metal systems, seals and bearings, electrical carbon, thermal ceramics (e.g. insulation), and technical ceramics. The first three groups all use coal tar pitch (CTP) as a key material. The importance of this material for Morgan activities is reflected, for example, by an expansion in Morgan’s factory in Swansea, which has just completed an investment in a new production line to extrude coal tar pitch-graphite particulate materials. However, the increasing environmental regulations and awareness raise concerns about the long-term appropriateness, availability and supply of coal tar pitch. 

This project spanned the research laboratories of the University of Manchester and Morgan, with the latter doing vital benchmarking and technical viability for commercialisationCrucially, the project leveraged the deep established academic-Morgan collaboration, the strong expertise that exists within the Valles/Kinloch research group and the wider Royce technical team. Royce’s facilities were the only, worldwide, able to deliver meaningful results in such a short time due to the range quality of the equipment available and the strength of the Morgan-academic collaboration.