LNG-Coupled Cryogenic Carbon Capture for Load-Shifting Power Plants
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current carbon capture and storage (CCS) technologies are energy-intensive and inefficient, particularly in utility-scale power plants, leading to increased fuel consumption and energy costs, while also facing challenges in managing fluctuating energy demand and intermittent energy sources like wind and solar.
Innovation Solution
Integration of energy storage with cryogenic carbon capture (CCC) systems, using refrigerants like liquefied natural gas (LNG) to cool and separate CO2 from flue gas, reducing parasitic load during peak demand and leveraging stored energy to enhance power generation, thereby improving energy efficiency and grid management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional refrigeration processes are used to cool process gases to very low temperatures for CO2 separation, then CO2 capture is achieved, but substantial energy is consumed in cooling and compressing
Solution Approach 1:
The process gas is pre-cooled by heat exchangers using cold refrigerant before entering the expansion device. This preliminary cooling action reduces the temperature and pressure of the gas, making the subsequent expansion and separation more efficient and reducing the overall energy required for the complete cooling process
Solution Approach 2:
The patent utilizes phase transitions of the refrigerant (between liquid and vapor phases) and phase changes of CO2 (from gas to solid via desublimation) to achieve separation. The refrigerant absorbs heat during evaporation and releases heat during condensation, while CO2 desublimates at specific temperature-pressure conditions, enabling efficient separation without requiring excessive cooling energy
2Object-affected harmful factors
If carbon capture and storage (CCS) technology is implemented in utility-scale power plants, then carbon emission control is achieved, but fuel consumption and energy costs increase significantly
Solution Approach 1:
The system uses its own process gas as the refrigerant medium. The CO2-rich process gas is circulated through the heat exchangers and expansion devices, cooling itself and other streams while undergoing pressure and temperature changes that facilitate CO2 desublimation. This self-service approach eliminates the need for external refrigerants and reduces parasitic energy losses
Solution Approach 2:
The patent converts the harmful CO2 emissions into a useful cooling medium. The CO2-rich process gas, which would normally be a waste stream requiring energy-intensive treatment, is instead utilized as the refrigerant that provides cooling throughout the system, transforming a harmful factor into a beneficial resource that reduces overall energy consumption
3Productivity
If energy storage is integrated with cryogenic carbon capture systems, then parasitic load during peak demand is reduced and power generation is enhanced, but system complexity increases
Solution Approach 1:
The process gas circulation system serves multiple functions simultaneously: it acts as the refrigerant for cooling, the medium for CO2 separation, and the working fluid for energy storage and power generation. The same CO2-rich gas that is being separated is used to provide refrigeration and can be stored or expanded to generate electricity during peak demand, eliminating the need for separate energy storage systems
Solution Approach 2:
The patent merges the carbon capture process with energy storage and power generation functions into a single integrated system. The heat exchangers, expansion devices, and process gas circulation are combined such that CO2 separation, refrigeration, and energy recovery occur simultaneously in the same equipment, reducing overall system complexity despite the multiple functions performed
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
The integrated system achieves significant energy efficiency gains by reducing the energy required for carbon capture, enabling effective load shifting and supplemental power generation, thus addressing both carbon emission control and energy management challenges.
Implementation Method 1
the LNG refrigerant cools a mixed process stream comprising at least one condensable vapor and at least one light gas, thereby causing the condensable vapor to desublimate
Implementation Method 2
The refrigerant is boiled by the mixed process stream, thereby cooling the mixed process stream
Implementation Method 3
The LNG refrigerant cools a mixed process stream comprising at least one condensable vapor and at least one light gas
Data Source
AI summary
The systems and methods integrate energy storage with cryogenic carbon capture, providing effective grid management and energy-efficient carbon capture capabilities to power plants. The systems store energy during off-peak demand by using off-peak energy to compress natural gas to form liquefied natural gas (LNG) and storing the LNG for use as a refrigerant. The systems use the stored LNG as a refrigerant in a cryogenic carbon capture (CCC) process to isolate carbon dioxide from light gases in a flue gas. The systems supply energy during peak demand by burning the natural gas warmed by the CCC process to generate power.