| Summary: |
The European Union has agreed in the Kyoto protocol to diminish 12% the emissions of carbon dioxide up to 2010 to avoid severe climate changing in our planet. Carbon dioxide emissions are quite high in the entire European continent with many countries being in the top 20 larger polluting countries of the world. Co-generation of electricity and heat has proved to be one of the most efficient and less polluting technologies for power generation. Even though, these centrals are still based on the combustion of fossil fuels, requiring additional processes for carbon dioxide sequestration and concentration for further uses. Many alternatives are already available for CO2 capture from flue gases: cryogenic process, absorption with monoethanolamine, MEA and membranes. Up to 1995, Pressure Swing Adsorption, PSA, adsorption technologies were the ones having the higher capture efficiency, although was penalized by global economics.
In this work we will study the feasibility of concentration and capture of carbon dioxide from flue gases of electric power centrals by Pressure Swing Adsorption (PSA) units. The objective of this work is the control of CO2 emissions via an adsorption process.
The initial part of the work is the screening of a selective adsorbent for carbon dioxide in the conditions where it has to be sequestrated: temperature around 100 - 150C and presence of nitrogen, oxygen and trace contaminants like NOx, CO and H2O. This screening involves selection and / or preparation of an adsorbent with high selectivity towards carbon dioxide with respect to the other main components (water, nitrogen and oxygen). The adsorbent screening involves the creation of a database of adsorption properties of different sorbents that can be used for CO2 sequestration. After adsorbent selection, the PSA process has to be specified. We will use as reference a four-step cycle comprising pressurization, feed, counter-current blowdown and purge at temperature around 373 K, conditio  |
Summary
The European Union has agreed in the Kyoto protocol to diminish 12% the emissions of carbon dioxide up to 2010 to avoid severe climate changing in our planet. Carbon dioxide emissions are quite high in the entire European continent with many countries being in the top 20 larger polluting countries of the world. Co-generation of electricity and heat has proved to be one of the most efficient and less polluting technologies for power generation. Even though, these centrals are still based on the combustion of fossil fuels, requiring additional processes for carbon dioxide sequestration and concentration for further uses. Many alternatives are already available for CO2 capture from flue gases: cryogenic process, absorption with monoethanolamine, MEA and membranes. Up to 1995, Pressure Swing Adsorption, PSA, adsorption technologies were the ones having the higher capture efficiency, although was penalized by global economics.
In this work we will study the feasibility of concentration and capture of carbon dioxide from flue gases of electric power centrals by Pressure Swing Adsorption (PSA) units. The objective of this work is the control of CO2 emissions via an adsorption process.
The initial part of the work is the screening of a selective adsorbent for carbon dioxide in the conditions where it has to be sequestrated: temperature around 100 - 150C and presence of nitrogen, oxygen and trace contaminants like NOx, CO and H2O. This screening involves selection and / or preparation of an adsorbent with high selectivity towards carbon dioxide with respect to the other main components (water, nitrogen and oxygen). The adsorbent screening involves the creation of a database of adsorption properties of different sorbents that can be used for CO2 sequestration. After adsorbent selection, the PSA process has to be specified. We will use as reference a four-step cycle comprising pressurization, feed, counter-current blowdown and purge at temperature around 373 K, conditions of a typical co-generation exhaust stream. Other steps arrangements will be considered. Impact on the adsorbent life due to poisoning with the contaminants will be considered. Following, scale-up and process economics (installation and operational costs and its impact in energy price) were evaluated. For the evaluation of the process economics, alternative uses of carbon dioxide will be considered in the local perspective. |