CO2 Capture Solvent Regeneration Using Low-Temperature Condensate Heat
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Solution Overview
Problem
Current CO2 capture systems from flue gases require significant energy for solvent regeneration, particularly in power generation plants, which reduces net power production and impacts efficiency.
Innovation Solution
The system utilizes heat from low pressure steam and condensed flue gas to heat reflux for solvent regeneration in a CO2 capture unit, reducing the need for high-temperature heat and minimizing solvent degradation, while also reducing water consumption and cooling requirements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by stationary object
If high temperature heat is used for solvent regeneration, then CO2 removal from rich solvent is achieved, but energy consumption increases and solvent degradation occurs
Solution Approach 1:
The patent changes the temperature parameter of the heating medium from high temperature (typically steam at 100-150°C) to low temperature (condensate at 30-50°C). This parameter change reduces energy consumption and prevents solvent degradation while still achieving effective CO2 removal through the temperature swing that enables desorption of CO2 from the rich solvent
Solution Approach 2:
The patent converts the normally wasted low-grade heat in condensate from the steam cycle into a useful heating medium for solvent regeneration. Instead of discarding the condensate at 30-50°C, it is utilized to heat the rich solvent, thereby converting a waste stream into a beneficial resource that reduces both energy consumption and solvent degradation
2Productivity
If steam is diverted to heat rich solvent, then CO2 capture is enabled, but power generation efficiency decreases
Solution Approach 1:
The patent enables the steam cycle to heat itself for CO2 capture purposes. The condensate from the steam cycle, which would normally be discarded, is reused to heat the rich solvent in the regeneration column. This self-service approach allows CO2 capture without requiring additional external energy inputs that would compete with power generation
Solution Approach 2:
The patent utilizes the phase transition of steam to condensate, capturing the thermal energy released during condensation. The condensate at 30-50°C retains sufficient thermal energy to heat the rich solvent for CO2 desorption, thereby harnessing the energy from the phase transition that would otherwise be wasted
3Power
If water is used for cooling condensate, then steam cycle efficiency is maintained, but water consumption increases
Solution Approach 1:
Instead of discarding the condensate after it leaves the steam cycle, the patent recovers and reuses it as a heating medium for solvent regeneration. This recovery approach eliminates the need for additional cooling water while maintaining steam cycle efficiency, as the condensate is utilized before requiring further cooling
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach decreases energy consumption for solvent regeneration, enhances plant efficiency, and minimizes the impact on power generation, achieving a 6% reduction in steam demand and improving CO2 capture processes.
Implementation Method 1
heat from condensed low pressure steam is utilized to heat reflux that is returned to a stripper
Implementation Method 2
heat from low pressure steam and condensed flue gas to heat reflux for solvent regeneration
Data Source
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AI summary
Systems and methods for reducing the energy requirements for carbon dioxide capture are described. Heat from system processes, such as steam condensation and hot flue gas, is utilized to heat reflux liquid utilized in release of carbon dioxide from absorbent solvent.