| Popis: |
Carbon anodes are presently produced from petroleum-derived coke and coal tar pitch. Upon consumption of these anodes, some 1.5 t CO2/t Al are generated. This considerable footprint could be reduced by using biomass-derived coke. It was suggested to manufacture coke from biomass char. However, the corresponding cokes typically contain undesired oxidation catalysts (alkali and alkaline earth metals), are high in oxygen (reducing carbon available for electrolysis), have undesired isotropic textures, and also have low bulk densities. In order to avoid these shortcomings, a new approach was studied: coking of biomass-derived oils from a fast pyrolysis process yielding lower-oxygen oil. The corresponding cokes are very low in undesired impurities (sulphur, vanadium, and nickel). Levels of oxygen, alkali and alkaline earth metals are acceptable. Using appropriate conditions, cokes with desired anisotropic textures can be produced. |
