Porous carbon anodes for the supply of methane during electrowinning of aluminium

Abstract

One of the major downsides of the current aluminium production process is the high amount of CO2 emission. One alternative is to replace the consumable carbon anodes with inert anodes so that oxygen evolves instead of CO2 and PFC emissions. However, so far a sufficiently inert anode has not been found. Another option is to utilize natural gas through porous anodes. This will decrease CO2 emission remarkably and also eliminate PFC emissions and anode effect. The porous anode could be made of carbon or it can be inert. However, the as-mentioned problem still exists regarding porous inert anodes. Therefore, at the moment porous carbon anodes seem to be the best practical option. In this study, porous anodes made of different grades of graphite were used for electrolysis experiments. Also, off-gas analysis was performed to get an insight of the ongoing reactions. Our results show that for some types of graphite anodes, methane participates effectively in the anodic reaction.