Heat Integration in CO2 Capture Power Plants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current CO2 capture technologies are energy-intensive, and there is a need for improved heat integration to enhance energy efficiency in power plants that capture CO2 from carbonaceous fuel combustion.
Innovation Solution
A method involving the combustion of carbonaceous fuels under pressure with oxygen, using heat pipes for steam generation within the combustion chamber, and a direct contact cooler for water recirculation and counter-current flow to enhance CO2 absorption and energy recovery, including heat exchangers for steam regeneration and recycling, which reduces energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CO2 capture is implemented using conventional methods (absorption, fuel conversion, or oxyfuel), then CO2 can be captured from exhaust gases, but energy consumption increases significantly
Solution Approach 1:
The patent combines multiple functions into integrated heat exchanger systems where exhaust gases serve dual purposes: cooling the combustion chamber and preheating combustion air. The heat exchangers merge thermal energy recovery with process heating, eliminating separate cooling and heating systems, thereby reducing overall energy consumption while maintaining CO2 capture efficiency.
Solution Approach 2:
The patent converts the harmful hot exhaust gases that would normally require energy-intensive cooling into a beneficial heat source. The exhaust gases are used to preheat combustion air and generate steam, transforming waste thermal energy into useful process heat, thereby reducing the energy penalty associated with CO2 capture.
2Quantity of substance
If combustion chamber cooling is implemented to enable CO2 capture, then steam can be generated, but energy loss increases due to heat removal
Solution Approach 1:
The patent implements a feedback loop where the steam generated from combustion chamber cooling is fed back into the process. The steam is used for power generation in turbines or for heating purposes, ensuring that the energy removed for cooling is not lost but rather returned to the system in a useful form, thereby eliminating net energy loss.
Solution Approach 2:
The combustion chamber cooling system serves multiple functions simultaneously: it cools the combustion chamber to enable CO2 capture, generates steam for power generation, and preheats combustion air. This multi-functionality ensures that steam generation does not represent energy loss but rather a valuable byproduct that supports overall plant efficiency.
3Productivity
If heat integration is implemented to improve energy efficiency, then energy output increases, but system complexity increases
Solution Approach 1:
The patent divides the heat integration system into distinct modular heat exchanger units, each handling specific heat transfer tasks (exhaust gas cooling, combustion air preheating, steam generation). This segmentation allows for independent design, operation, and maintenance of each module, reducing overall system complexity while achieving high energy efficiency through coordinated operation.
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 significantly increases energy efficiency by maximizing heat and electricity output while minimizing energy loss, achieving high CO2 capture efficiency with reduced energy requirements.
Implementation Method 1
the combustion gas is cooled in the combustion chamber by generation of steam inside heat pipes provided in the combustion chamber
Implementation Method 2
a direct contact cooler for water recirculation and counter-current flow to enhance CO2 absorption and energy recovery
Implementation Method 3
including heat exchangers for steam regeneration and recycling
Implementation Method 4
CO2 is separated from the combustion gas by absorption / desorption
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A power plant for combustion of carbonaceous fuels with CO2 capture, comprising a pressurized fluidized bed combustion chamber (2), heat pipes (8, 8') for cooling of the combustion gas in the combustion, a direct contact cooler (15), a cleaned exhaust pipe (18) for withdrawal of the exhaust gas from the direct contact cooler (15) and introduction of the cooled exhaust gas into a CO2 absorber (19), where a lean exhaust pipe (20) is connected to the top of the absorber (19) for withdrawal of lean exhaust gas from the absorber (20), and a rich absorbent pipe (30) is connected to the bottom of the absorber (19) for withdrawal of rich absorbent and introduction of the rich absorbent into a stripping column (32) for regeneration of the absorbent to give a lean absorbent and a CO2 stream that is further treated to give clean CO2, where a water recirculation pipe (16) is connected to the bottom of the direct contact cooler (15) for withdrawal of used cooling water and connected to the top of the direct contact cooler(15) reintroduction of the cooling water at the top of the direct contact cooler, wherein a heat exchanger (17) connected to water recycle pipes (70, 70') for delivery and withdrawal, respectively, of cooling water to the heat exchanger, is provided in the recirculation pipe (16) for cooling the circulating direct contact cooler cooling water in pipe (16).