CO2 absorption in power plants

by Athina Kouneli

Institution: Högskolan i Gävle
Year: 2016
Keywords: Engineering and Technology; Environmental Engineering; Energy Systems; Teknik och teknologier; Naturresursteknik; Energisystem; Energisystem – magisterprogram (sv eller eng); Energy systems – master’s programme (one year) (swe or eng); Energy systems; Energisystem
Posted: 02/05/2017
Record ID: 2081206
Full text PDF: http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-21842


Carbon dioxide, the famous and vital to life gas, is also an important greenhouse gas. Since the combustion of fuels leads to the production of carbon dioxide it had to be expected that since the industrial revolution the concentration of carbon dioxide in the atmosphere was to be rapidly increased. When the consequences and the causes of the greenhouse effect were understood, serious efforts were made by the global community to reduce the greenhouse gases production and CO2 among them. The Kyoto Protocol, an international agreement linked to the United Nations Framework Convention on Climate Change, commits State Parties, also EU among them, to reduce the greenhouse gases by setting internationally binding emission reduction targets. The first commitment period started in 2008 and ended in 2012 and had as goal an average 5% reduction of carbon dioxide and other greenhouse gases, whereas during the second commitment period (2013-2020) the parties committed to reduce greenhouse gas emissions at least 18% below the 1990 levels. Greenhouse gas emissions in the EU-28 in 2013 stood at 4611 million tones of CO2 and the fuel combustion and the fugitive emissions were responsible for the 57.2% of the carbon dioxide production. The electricity, gas, steam and air conditioning supply activities account for the 26.6% of the emissions. Therefore it can be easily understood that the power plants is an important sector in CO2 production and therefore their carbon dioxide emissions need to be reduced. Carbon capture and storage (CCS) process is one of the available solutions to reduce the greenhouse gases. With CCS it is possible to capture the CO2 waste from large point sources and to transport it and deposit to a storage site, usually to a geological formation. This way the carbon dioxide can be prevented from getting released into the atmosphere. Within the framework of this thesis only the capture process of this method is to be examined. More specifically this thesis project involves research over a mature technology for CO2 capture, able to be adapted at plants exhaust gases. This technology is carbon dioxide absorption. The research on CO2 absorption today appears to focus mostly on power plants gases as the gases production of power plants are increased in comparison to other plants. It is indicated that using the classic solvents - amines for the CO2 absorption system results to a significant amount of energy consumption for the solvents regeneration. The purpose of this thesis is to search over the biphasic solvents as an alternative option to amines for the CO2 capture system and state the pros and cons mainly from the energy aspect. It is expected that the biphasic solvents contribute to energy reduction of the system as the solvents are separated into two phases after the absorption, giving the capability to remove the water phase from the absorption column and as a result use less energy in the regeneration column.