Integration of CO2 capturing from flue gases using Aqueous Ammonia for Low Emissions Urea Production

Abstract

Carbon Capture and Utilization is one the potential solution to mitigate global warming. In this study, aqueous ammonia is used for capturing CO2 from flue gases, the produced slurry is then utilized for urea production. In this work, modification is conducted to the original solid controlled formation chilled ammonia process. During this, ammonium carbonate slurry is produced, which can play a crucial part as intermediate element in urea synthesis. Process stream integration and waste energy utilization are considered in many points, in addition to, urea revamp to accommodate this modification. The proposed modification is simulated in Aspen Plus using extended thermodynamics model. Due to this modification and process integration, the regeneration section and effluent treatment section were completely removed which greatly decreased energy consumption. It is found that, energy consumption in the solid controlled formation process decreased by 23.4%. Moreover, through the proposed energy integration with the urea production plant, a zero-energy consumption is reached together with an increase in urea production by 8 t/hr. This also has an environmental impact as the amount of associated CO2 emissions decreased by 6% which affected the carbon footprint of the plant. Our work is in agreement with the United Nation Sustainable Development Goals; goals number 2, 7 and 13. Utilizing carbon dioxide emissions initiated a transformative shift in industrial practices in alignment with sustainability requirements.