Comparative analysis of CO₂ capture systems : an exergetic framework
Abstract/Contents
- Abstract
- A portfolio of technology strategies will be needed to reach overall greenhouse gas emissions targets. Implementing systems to separate CO2 from atmospheric emissions of fossil-fuel power plants is predicted to be a necessary part of this portfolio, especially in the near term. However, existing carbon capture systems are quite inefficient, using or otherwise reducing a significant portion of power plants' electricity output. In order to improve future systems and make them viable, it is important to understand which aspects of each system have the most potential to improve, and which systems overall are most promising for future research and development. In this work, we examine three representative options for CO2 capture systems. The first option, an amine absorption system for post-combustion capture, is studied due to its relative technological maturity. The second system uses vacuum-swing adsorption and is examined as a post-combustion alternative to the amine system. The third option is a novel system using oxyfuel combustion in supercritical water, which facilitates CO2 separation while reducing the irreversibility inherent in fuel combustion. For each of these options, the current state of the system is modeled and assessed, and the potential for improvement of the system's efficiency is identified and discussed. This assessment is done via an exergy analysis, for several reasons. First, an exergy analysis provides a direct way to compare each process or unit operation to its thermodynamically optimal limit. This gives an immediate sense of how much improvement is actually still possible, thermodynamically, in that process or unit operation. Second, exergy analysis is a useful tool to compare---on a common basis---systems that use different types of inputs (heat vs. work vs. matter transfers), such as the three systems studied here. The first goal of this work is to give targeted recommendations for each type of system---and to discuss potential limitations---based on the results of the exergy analyses. A second goal of this work is to provide the correct theoretical modeling framework to allow an exergy analysis of these types of systems. Because each of these systems deal with non-standard fluids, calculation of thermodynamic properties relevant to performing an exergy analysis of these systems is not trivial. The relevant thermodynamic theory is extended where necessary, in particular in the case of the adsorption system.
Description
| Type of resource | text |
|---|---|
| Form | electronic; electronic resource; remote |
| Extent | 1 online resource. |
| Publication date | 2015 |
| Issuance | monographic |
| Language | English |
Creators/Contributors
| Associated with | Calbry-Muzyka, Adelaide S |
|---|---|
| Associated with | Stanford University, Department of Mechanical Engineering. |
| Primary advisor | Edwards, C. F. (Christopher Francis) |
| Thesis advisor | Edwards, C. F. (Christopher Francis) |
| Thesis advisor | Brandt, Adam (Adam R.) |
| Thesis advisor | Mitchell, Reginald |
| Advisor | Brandt, Adam (Adam R.) |
| Advisor | Mitchell, Reginald |
Subjects
| Genre | Theses |
|---|
Bibliographic information
| Statement of responsibility | Adelaide S. Calbry-Muzyka. |
|---|---|
| Note | Submitted to the Department of Mechanical Engineering. |
| Thesis | Thesis (Ph.D.)--Stanford University, 2015. |
| Location | electronic resource |
Access conditions
- Copyright
- © 2015 by Adelaide Sarah Calbry-Muzyka
- License
- This work is licensed under a Creative Commons Attribution Non Commercial 3.0 Unported license (CC BY-NC).
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