Comparison of CLC with existing CCS technologies: based on Energy, Exergy and Techno-economic analysis

Abstract

Climate change is an immediate global crisis that is driven by the accumulation of greenhouse gases, primarily carbon dioxide, in the Earth´s atmosphere. Carbon Capture and Storage (CCS) technologies play a pivotal role in reducing our carbon footprint as we move towards a more sustainable future. This study aims to compare four different carbon capture technologies and evaluate them based on techno-economic analysis, energy analysis and exergy analysis. The four technologies under evaluation are chemical looping combustion (CLC), oxy-fuel combustion, post-combustion, and pre-combustion. The process modelling of the four systems for a selected combined heat and power (CHP) plant is used to carry out this comparison, which is next followed by energy, energy-related, and economic analysis. The modelling of these four plants was conducted using Aspen Plus simulation software and validated using the results given in the literature. The study reveals that the CLC capturing technology outperforms other CCS processes regarding cost efficiency, CO2 capture rate and electrical efficiency. The highest overall efficiency was observed for Oxyfuel combustion but the CLC plant has the best net electric efficiency. For the CLC model, An almost pure stream of CO2 is extracted from the Fuel reactor which is then subsequently compressed after heat extraction. The CLC has the highest CO2 capture rate among the four models for this reason. From the exergy analysis, it becomes clear that the most exergy destruction takes place in the combustion process for all the cases and that it needs to be optimized to improve overall efficiency. The comparison of the overall exergy destruction of the models shows us that CLC has the least exergy destroyed and thus has the highest exergy efficiency, despite incurring higher initial expenses, CLC displays the lowest levelized cost of electricity (LCOE) and payback period when compared with all the other technologies. This indicates that CLC has been estimated to be the most economical choice over the long term, despite necessitating a more substantial initial expenditure. To sum up, this case study offers insightful information about the advancement of CLC technology and its advantage over competing carbon capture solutions. The results provide a useful manual for energy sector decision-makers, highlighting how important it is to select the appropriate carbon capture and combustion technology with the intent to optimise performance and economics