Defossilization of Industrial Glass Production via Carbon Capture and Utilization of Flue Gas

The glass industry faces significant challenges in achieving carbon neutrality due to its reliance on fossil fuels and process-related CO2 emissions from raw material decomposition. While most defossilization efforts focus on CO2-neutral heating, batch-related emissions remain largely unaddressed. This study investigates a closed carbon cycle approach for glass manufacturing by integrating carbon capture and utilization (CCU) with power-to-gas technologies. The proposed process captures both combustion- and batch-related CO2 emissions and converts them into synthetic natural gas using renewable hydrogen. The techno-economic model, based on a typical oxy-fuel container glass furnace (300 t per day) and current (2022) German market conditions, covers all key process steps: flue gas cleaning, CO2 separation, hydrogen production via electrolysis, and methanation. Results show that more than 99 % of scope 1 emissions and about 62% of scope 1+2 emissions can be abated. However, the process is associated with high energy demand and costs, with energy supply alone amounting to €559 (2022) per metric ton glass at an electricity price of €60 per MWh. The cost of CO2 abatement is estimated at €1132 (2022) per metric ton. While all process steps are based on established industrial technologies, the overall economic viability remains highly sensitive to electricity prices and further technological improvements. The approach is especially relevant for high-quality glass production with low cullet content and in regions with abundant renewable electricity.