Today, Elkem’s Norwegian smelting plants emit approx. 1500 ktons CO2/year, most of this coming from the flue gas. The FEL 1 study has established a detailed process design basis for CCS from flue gas at Elkem’s FeSi/Si smelting plants, as well as developed a generic model for calculation of CAPEX and OPEX related to implementation of CCS at the various plants. The work has been done in cooperation with the two technology suppliers Aker Carbon Capture with their amine capturing process, and Saipem who utilizes an aqueous solvent and enzyme for CO2 capturing. This was done to learn more on the effects on the total scope and costs for Elkem by the different technology choices. To assess the energy requirements and energy recovery, Norsk Energi was consulted. Optimizing the energy part is important since it is a substantial part of the CCS cost, takeaway is that this needs further assessment. Heat utilization from available process hot water should be further investigated. New technology was piloted at Sintef, with recirculation of silicon process flue gas to increase the CO2 concentration, and where the result shows that moderate flue gas recirculation appears as a good solution, and it will also reduce the NOx emission. Other potential to increase the CO2 content in the flue gas is by reduction of false air and unintended leakages in the off-gas system. The study has given valuable information and knowledge that will be utilized in Elkem’s strategic planning towards climate neutrality.
More information:
• https://www.elkem.com/media/news/article/?itemid=16888EE6FEC0B610
• https://www.ntnu.no/blogger/teknat/2021/05/27/resirkulering-av-avgass-i-silisiumproduksjon/
• Attendance in the CCUS Academy webinar: Possibilities for industrial partnerships to fast-track emission reductions
• https://gemini.no/2021/06/a-resirkulere-avgasser-kan-bidra-til-karbonfangst/ (gemini.no)
• https://www.tu.no/artikler/ved-a-resirkulere-avgassene-kan-co2-fangst-pa-silisiumproduksjon-bli-billigere/510583?key=0bXiZHab (Tu.no)