The Path to Zero Carbon Dioxide Emissions in Silicon Production

Abstract

The global community has set a path towards carbon neutrality by 2050. Almost one-fourth of the global emissions is attributed to direct emissions from industrial processes. Therefore, a zero-carbon alternative must be developed for each process, including the production of silicon. The silicon industry is exploring ways to efficiently capture CO2 from the flue gases from the submerged arc furnaces, for example by increasing the CO2 concentration. Replacing fossil reducing agents with biofuel is a carbon neutral alternative, while recycling waste streams from aluminium production as a reducing agent for silicon, is a more recent development. Electrochemical methods have also been explored at a laboratory scale. This paper gives a review of the efforts to date, from industry and academia, to decarbonize the production of silicon. The development of the largest part of the carbon footprint, arising from the production of the electrical energy used, is also discussed.