Number
273-EN
Section
General Section
Use
Sector
Health services
Scientific research and development
Function
Other
Process
Other
Product category
other
Application
Bio-pitch
Abstract
Bio-pitch can be mixed with char-coal to obtain electrodes. The study presents results of tests carried out with bio-pitch electrodes obtained under various conditions from eucalyptus oil.
Substituted substances
Coal tar pitch
CAS No. 90669-59-3 EC No. 292-654-0 Index No. 648-070-00-7
Chemical group
Hydrocarbons
Classification: hazard statements
H350 May cause cancer
Alternative Substances
Eucalyptus oil bio-pitch
CAS No. EC No. Index No.
Chemical group
Essential oils
Reliability of information
Internet information: data are from an internet document and only a basic and partial evaluation could be performed
Reason substitution
CMR
Hazard Assessment
Substance to be substituted: Coal tar pitch is a classified EU carcinogen 1B, it may cause cancer Alternative substance: Bio-pitch is made from eucalyptus oil that is not known to be carcinogenic; it is not listed in the SUBSPORTplus screening criteria (SDSC) database for hazardous substances
Description of Substitution
Coal tar pitch is obtained as a by-product in coal processing and is used in various processes including manufacturing of electrodes. It has a complex composition with a high proportion of polycyclic aromatic hydrocarbons (PAHs) which are generally hold responsible for its carcinogenic effect. Research is carried on to find safer, suitable alternatives. A pilot study prepared calcined and graphited electrodes from mixtures of eucalyptus oil pitch and charcoal. Tests were made to determine their composition and compare them to electrodes made with coal or petroleum tars. The eucalyptus wood oil was obtained by slow pyrolysis at low temperatures (260 0C, about 100 0C lower than for coal or petroleum pitches) and reduced pressure (0.05MPa). The yield in bio pitch was around 50 %wt. The bio pitch was mixed with ground charcoal and pressed at 60MPa to obtain cylindrical electrodes that were afterwards calcined (10000C) and graphited (27000C). Composition analyses showed a high rate of polar compounds in the bio-pitch (80-86%) most of them monoaromatics, while in coal tar pitch polyaromatics are preponderant. Tests were made on the sample electrodes for electrical resistivity, Young’s modulus, density, porosity and other parameters. The conclusion of the study was that bio pitch may be considered as a possible alternative for coal tar pitch in electrodes.
Case/substitution evaluation
Making bio-pitch from biomass has the advantage of using renewable resources, reducing the carbon footprint and the sulphur emissions, a major contributor to acidification. The composition of bio-pitche obtained from eucalyptus is considered safer because of the low content in PAHs and by comparison with different types of eucalyptus oils (CAS 84625-32-1/ 85203-56-1) that are not known to be carcinogens but are self-classified by some sources as skin sensitisers, so handling with precaution is needed. Some companies in Brazil (where the study was made) turned to bio-oil recovery putting it on the market at a competitive price.
State of implementation
Pilot study
Date and place of implementation
pilot study in 2001, in Brasil
Availability of Alternative
pilot study
Type of information supplier
Research
Contact
J.D.Rocha, A.R.Coutinho and C.A. Luengo (2002), Biopitch Produced from Eucalyptus Wood Pyrolysis Liquids as a Renewable Binder for Carbon Electrode Manufacture, Brazilian Journal of Chemical Engineering
Type of publication and availability
Article in scientific journal, free access
Publication source: author, company, institute, year
The description is based on the article by Rocha, J.D., Coutinho, A.R., & Luengo, C.A.. (2002)' Biopitch produced from eucalyptus wood pyrolysis liquids as a renewable binder for carbon electrode manufacture', Brazilian Journal of Chemical Engineering, 19(2), 127-132.
Publication source
Type of publication and availability
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0104-66322002000200002
Date, reviewed
November 26, 2021