Techno-Economic Analysis of CO2 Capture Processes from Coal-fired Power Plants

Abstract Environmental regulations for flue gas emitted from coal-fired power plants in past mainly focused on sulfur oxides (SOx), nitrogen oxides (NOx) and particulate matter (PM) generated during combustion. Actions and regulations for preventing global climate change have been actively addressed in these days and considerable attentions are being paid to the implementation of CO2 capture and sequestration technologies. A wide range of CO2 separation techniques based on amine solvents, CO2 adsorbents, membranes and so on, are available and each technology has own technical advantages and disadvantages. Therefore, Techno-Economic Analysis (TEA) is required to compare CO2 separation processes in a systematic and fair manner and, hence, to gain full understanding of techno-economic impacts associated with the introduction of CO2 capture processes in process industries. This presentation discusses costing basis and assumptions required for TEA, as well as explains costing methodology based on multi-parameters scaling concept. Major equipment cost, indirect cost (e.g. EPC cost, owner’s cost, contingency, etc.) and operating & maintenance cost are considered for economic costing. In order to improve the accuracy of TEA results, reliable costing data and scale parameters are applied, based on industrial practices. Widely-practiced values for finance-related parameters, like interest rate and project life time for economic analysis, are adopted. The economics of several post-combustion CO2 capture processes applied for coal-fired power plant is analyzed with the proposed TEA tool. A case study is carried out to demonstrate the applicability of TEA tool for evaluating CO2 removal technologies and to provide economic impacts associated with capture processes. Process optimization is conducted for each CO2 removal technology and TEA is made for the optimized process configurations with optimal operating conditions, as unrealistic results may be obtained with non-optimal process design. The process optimization is carried out with integrated framework in which process simulator and in-house models are linked with an optimization solver. Techno-economics of CO2 capture processes was evaluated on the basis of the Cost of Electricity (COE), the cost of CO2 captured and the cost of CO2 avoided. Breakdown of TEA results for each technology are made and compared to obtain comparative guidance for areas of further process development. Because the introduction of CO2 capture process results in process changes/modifications of the power plant, increase in cost for power plant and CO2 capture process is separately analyzed. Sensitivity analysis is also done to understand impacts on costing when key design or costing parameters are varied.