“RUSAL Engineering-Technological Center” LLC, Saint Petersburg, Russia:

V. S. Burkat, Director of Ecology Department
K. I. Zorko, Specialist of Department of Ecoanalytical Measurements of Ecology Department, e-mail: Kirill.Zorko@rusal.com

RUSAL Global Management B. V., Moscow, Russia:
I. I. Rebrik, Director of Department of Ecology, Labor Protection and Industrial Safety of United Company RUSAL

Taking into consideration that aluminium production represents a source of emission of significant quantities of greenhouse gases (carbon dioxide, perfluorocarbons) in atmosphere, RUSAL pays a significant attention to reduction of emission of greenhouse gases in atmosphere. Instrumental measurements of CF₄ and C₂F₆ concentration in electrolysis gases were carried out at Krasnoyarsk Aluminium Smelter in 2007–2008, in order to determine the amount of perfluorocarbons emission from electrolyzers in the process of electrolytic production of aluminium. Concentration of gaseous perfluorocarbons in gases, removed from electrolyzers in the process of aluminium production, was determined in the time of anode effects by FTIR spectrometer Temet DX4000, with application of special methodology. Intensity of perfluorocarbons emission was up to 0.083 kg of AF₄/t of Al and 0.004 kg of C₂F₆/t of Al. This fact was confirmed by measurements of perfluorocarbon emissions from 174 KA Soderberg electrolyzers with upper current lead and without VSS. Emission intensity for upper current lead 174 KA Soderberg electrolyzers, equipped with VSS-PF system, was 0.043 kg of AF₄/t of Al and 0.0031 kg of C₂F₆/t of Al. Measurements in gases from 143 KA electrolyzers with prebaked anodes and PFPB system demonstrated that emission intensity was up to 0.055 kg of AF₄/t of Al and 0.0084 kg of C₂F₆ /t of Al. Results of the carried out work demonstrated that equipping of Soderberg electrolyzers with upper current feed with PFPB systems allows the significant reduction of total emission of perfluorocarbons in electrolytic aluminium production process.

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