Partial Replacement of Coke with Biocoke: Effect of Biocoke Production Temperature on Anode Quality

Abstract

Carbon anodes used in aluminum electrolysis are made of petroleum coke, coal tar pitch, recycled anodes, and butts. In order to reduce emissions of greenhouse gases (GHG), a group of researchers succeeded to replace a part of petroleum coke with biocoke modified using additives. Biocoke is obtained by the pyrolysis of wood chips at a temperature of about 1100 ºC, which is similar to the maximum temperature reached during anode baking. The focus of this study is the effect of biocoke production temperature on the anode quality. In this study, biocoke was produced at four different temperatures (600, 750, 950, and 1100 ºC). Anodes were produced without biocoke (standard anode) as well as with modified and non-modified biocokes. Then the anodes were characterized by measuring their densities, electrical resistivities, air and CO2 reactivities, and bending strengths. The effect of biocoke production temperature on anode quality was determined by comparing the anode properties.KeywordsBiocoke productionBiocoke calcination temperatureBiocoke modificationAnode propertiesPetroleum coke