Economic assessment for CO2 capture technologies in large combustion plants

Abstract

Consulta en la Biblioteca ETSI Industriales (8070)

[EN] Global warming is an issue that is growing in importance; efforts all over the world are being done in order to reverse this phenomenon. It is believed to be caused basically by the increase in concentration of atmospheric CO2 in the last decades. The main source of this CO2 is electricity generation in fossil fuels power plants. While other energies are developed or better efficiencies are achieved in renewable sources energies, fossil fuel energy is claimed to be necessary to continue with current life style. Hence, CO2 is needed to be eliminated from flue gases in order to be environmentally friendly. This goal is feasible if CO2 capture and sequestration (CCS) systems are implemented. The aim of this study is to asses CCS systems, considering the whole chain of sequestering CO2 (i.e. capture, transport and storage) highlighting on the capture. CO2 capture is an energy intensive process, being the most expensive process in a CCS system. Three capture approaches are under study (i.e. post-combustion, precombustion and oxy-fuelling) explaining their technical and economical benefits. Apart of the chosen approach, various technologies are considered. Some of them are not yet available having no more than some researches and theoretical data about them, but two of them are deeply studied (i.e. physical absorption and chemical absorption). An economical review of all this options is done in order to clarify the difference between each option. MIT and IPCC studies are used. The COE, CCA and total capital costs are chosen as the main values to compare the different data. As a conclusion, nowadays, the more feasible option is the post-combustion capture with chemical absorption using MEA or any other hindered amine. Thus this option is truly energy intensive, is the only option already available and the only one than can achieve reasonable efficiency when treating flue gases with its low CO2 concentration. For the near future, oxy-fuelling plants are claimed to be the response to CO2 problems, but further research is needed in the air separation unit (ASU) so less energy is required by it, reducing the cost of the generated electricity. Another feasible option is IGCC plants with pre-combustion separation unit using Selexol. This last technology is closer to be commercially available than oxyfuelling.