Analysis of a natural gas combined cycle powerplant modeled for carbon capture with variance of oxy-combustion characteristics

Show simple item record

dc.contributor Woodbury, Keith A.
dc.contributor Williamson, Derek G.
dc.contributor.advisor Midkiff, K. Clark
dc.contributor.author Breshears, Matthew Joseph
dc.date.accessioned 2017-03-01T14:41:32Z
dc.date.available 2017-03-01T14:41:32Z
dc.date.issued 2011
dc.identifier.other u0015_0000001_0000609
dc.identifier.other Breshears_alatus_0004M_10606
dc.identifier.uri https://ir.ua.edu/handle/123456789/1114
dc.description Electronic Thesis or Dissertation
dc.description.abstract The world's ever growing demand for energy has resulted in increased consumption of fossil fuels for electricity generation. The emissions from this combustion have contributed to increasing ambient levels of carbon dioxide in the atmosphere. Many efforts have been made to curb and reduce carbon dioxide emissions in the most efficient manner. The computer process modeling software CHEMCAD was used to model a natural gas combined cycle powerplant for carbon capture and sequestration. Equipment for two proven carbon capture techniques, oxy-combustion and post-combustion amine scrubbing, were modeled. The necessary components modeled included an air separation unit, powerplant, amine scrubbing unit, and a carbon dioxide compression and drying unit. The oxygen concentration in the oxidizer supplied to the powerplant was varied from ambient air, 21%, to nearly pure oxygen, 99.6%. Exhaust gas recirculation was incorporated to maintain a constant combustion temperature. At ambient conditions no air separation unit was necessary and all carbon capture was provided by the amine scrubbing unit. At concentrations ranging from 22 - 99% both oxy-combustion and amine scrubbing techniques are used at inversely varying degrees. At 99.6%, no amine scrubbing unit was necessary. As the oxygen concentration was varied operational parameters were investigated with the goal of identifying optimum operational conditions. Across the varying oxygen concentrations, the First Law efficiency losses ranged from 3.3 - 13.6%. The optimal operational point occurred when ambient air was supplied and exhaust gas recirculation was utilized for flame temperature control. A Second Law efficiency of 52.2% was maximized at an oxygen concentration of 22%. This corresponds to a 2.28% reduction in Second Law efficiency. An exergy analysis of each component identified the air separation unit as the component where the most improvements are possible. At 99% oxygen concentration, the Second Law efficiency of the air separation unit was 3%. Through modeling a natural gas combined cycle powerplant for carbon capture and varying the oxy-combustion characteristics, valuable information was gained in the understanding of operational losses associated with carbon capture.
dc.format.extent 113 p.
dc.format.medium electronic
dc.format.mimetype application/pdf
dc.language English
dc.language.iso en_US
dc.publisher University of Alabama Libraries
dc.relation.ispartof The University of Alabama Electronic Theses and Dissertations
dc.relation.ispartof The University of Alabama Libraries Digital Collections
dc.relation.hasversion born digital
dc.rights All rights reserved by the author unless otherwise indicated.
dc.subject.other Mechanical Engineering
dc.subject.other Alternative Energy
dc.title Analysis of a natural gas combined cycle powerplant modeled for carbon capture with variance of oxy-combustion characteristics
dc.type thesis
dc.type text
etdms.degree.department University of Alabama. Dept. of Mechanical Engineering
etdms.degree.discipline Mechanical Engineering
etdms.degree.grantor The University of Alabama
etdms.degree.level master's
etdms.degree.name M.S.


Files in this item

This item appears in the following Collection(s)

Show simple item record

Search DSpace


Browse

My Account