Biopitch produced from eucalyptus wood pyrolysis liquids as a renewable binder for carbon electrode manufacture

Abstract

Interest in biomass as a clean source of fuel, chemicals and materials is growing fast. What is attractive about biomass is its renewability and that it is CO2 balanced and sulfur-free. Biomass pyrolysis produces charcoal, bio-oil and gases in different proportions, depending on the technology and raw material used. In this study biopitch, a substitute for fossil pitches in electrodes, was produced from bio-oil distillation in bench-scale equipment. Biopitch and charcoal were mixed and thermically modified to give prebaked electrodes. The physico-chemical and mechanical properties of the biopitch and final electrodes were measured and compared with those of coal tar and petroleum materials. Despite their similar application, biomaterials are structurally and chemically different from minerals. The oxygen content in biopitch is ca 20 wt% and in mineral pitches it is no more than 2 wt%. Characterization experiments for electrode samples measured electrical resistivity, Young's modulus, rupture strength, density, porosity and proximate analysis.