Life Cycle Model to Address the Environmental Sustainability of Carbon Capture and Storage Systems

In an attempt to minimize greenhouse gas emissions and control the gradient of carbon concentration rise in the atmosphere, CO2 capture and storage (CCS) is gaining traction in many countries around the world. CCS refers to the capture and storage of the greenhouse gas (GHG) CO2 in geological formations or other suitable storage places. CCS is well suited for large point sources of emissions, such as power plants and other industrial sites. Also, life cycle assessment (LCA) is a strategy that belongs to the family of lifecycle thinking approaches and is an effective instrument for assessing environmental performance which provides a more comprehensive view of environmental implications, including greenhouse gas (GHG) emissions, and allows decision-makers to quantify the trade-offs inherent in every modification to the power generation systems. This thesis presents a life cycle assessment (LCA) on carbon dioxide capture and storage (CCS), creating a comprehensive LCA methodology for the "gate-to-gate" evaluation of potential CCS technologies. Life Cycle Inventory (LCI) database that represents inputs/outputs of processes at a high degree of detail, adjusts for technological and regional variances, produces LCI data in a consistent and transparent way, and has a flexible structure has been designed and organized. All CO2 capture and storage methods will show an increase in cumulative energy demand with environmental effects and a significant reduction in greenhouse gas (GHG) emissions. The proposed LCI models were effectively used to post-combustion chemical absorption capture, pipeline transportation, and saline aquifer storage. This study examines the LCI models for chemical absorption CO2 capture base on empirical relationships, with the aim of introducing more parameters into the LCI model for CO2 conditioning in post-combustion CO2 capture. Furthermore, the designed LCI model provides a flexible framework for estimating energy consumption and emissions from CO2 pipeline transportation and injection. Then, using LCA modeling of geological storage, calculate CO2 distribution in the saline aquifer and evaluate multiple models of CO2 leakage through different paths. Lastly, by Implementing a case study of a carbon capture, transportation, and storage project at the Asnaes coal power station in Kalundborg, Denmark, and the life cycle impact assessment (LCIA), a model is presented that not only quantifies the emissions from the constructed system and the relating LCA environmental impacts, but also analyzes the variation through the provided sensitivity analysis, operational conditions, reservoir characteristics, and alternative leakage pathway parameters that have a significant effect on the LCA environmental impact results. Consequently, post-combustion chemical absorption (MEA) CO2 capture unit captures 95% of CO2 and emits less PM-10, SO2, SO3, NO2, HCl, HF, mercury (Hg) vapor. As well, MEA production, MEA transport, CO2 pipeline infrastructure, CO2 capture facility infrastructure, and compressor infrastructure, have very modest life-cycle environmental effects. The AP, EP, GWP, HTP, and POCP are all significantly impacted by emissions into the atmosphere. Trace metal emissions to the air or soil are the primary causes of the FAETP and TETP. Also, changes in the capture rate and the required amount of energy can have a significant effect on all of the categories. In contrast, the length of the pipeline and the transport pressure do not affect the life-cycle impacts in the majority of categories. Using K PZ or KS1 to chemically absorb CO2 has a smaller environmental impact than using MEA to achieve the same result. Lastly, the ratio of potential CO2 leakage to total CO2 injected is sensitive to changes in the injection period and injection rate.