LNG Cold Heat CO2 Capture System for Power Plant Flue Gas
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Solution Overview
Problem
Current methods for capturing carbon dioxide from flue gas discharged by power generation facilities are inefficient and costly, and the use of seawater for liquefied natural gas (LNG) regasification can harm marine ecosystems, while traditional energy-based regasification methods waste energy.
Innovation Solution
A carbon dioxide capturing apparatus utilizing the cold heat of liquefied natural gas (LNG) to cool a primary coolant, which is then used to capture CO2 from flue gas through a series of heat exchangers and chillers, achieving cryogenic temperatures to convert CO2 into dry ice, thereby reducing emissions and improving safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If seawater is used for LNG regasification, then regasification can be performed without energy consumption, but marine ecosystems are harmed
Solution Approach 1:
The patent introduces a heat exchanger as an intermediary device that enables heat transfer between LNG and seawater without direct contact between the two. The heat exchanger allows thermal energy exchange while preventing seawater contamination, thus resolving the contradiction between energy efficiency and ecological protection
Solution Approach 2:
The system segments the regasification process into separate functional components: LNG storage, heat exchange, and seawater circulation. By dividing the system into distinct modules with dedicated functions, the patent enables controlled heat transfer while isolating seawater from direct contact with LNG, preventing ecological harm while maintaining energy efficiency
2Ease of manufacture
If natural gas is burned to generate heat for LNG regasification, then regasification can be performed, but energy is wasted
Solution Approach 1:
The patent converts the cold energy of LNG, which would otherwise be wasted during regasification, into a useful resource for CO2 capture. The cold heat from LNG is used to cool the coolant to cryogenic temperatures, enabling efficient CO2 separation from flue gas, thus transforming a waste stream into a valuable asset
Solution Approach 2:
The LNG regasification process is given multiple functions: it not only regasifies LNG for distribution but also provides cold energy for CO2 capture from power plant flue gas. This multi-functionality eliminates energy waste by utilizing the cold heat that would otherwise be discarded
3Productivity
If conventional CO2 capture technologies are used, then CO2 removal can be achieved, but cost and efficiency are insufficient
Solution Approach 1:
The patent changes the temperature parameter of the coolant to cryogenic levels (below -100°C) by utilizing LNG cold heat. This parameter change enables CO2 to condense from flue gas at much lower temperatures than conventional capture methods, dramatically improving separation efficiency while reducing operational costs by eliminating the need for energy-intensive cooling systems
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 apparatus effectively captures carbon dioxide from flue gas, reducing atmospheric emissions and improving the safety of the capture process by utilizing the cold heat of LNG to achieve cryogenic temperatures, enhancing the efficiency of CO2 removal and minimizing environmental impact.
Implementation Method 1
a heat exchanger configured to cool primary coolant using heat exchange between the primary coolant and liquefied natural gas (LNG)
Implementation Method 2
a chiller connected to the heat exchanger and configured to discharge capturing coolant that is colder than the primary coolant by performing a heat exchange between the capturing coolant and a cooling material
Implementation Method 3
a capturing cooler configured to capture carbon dioxide contained in flue gas by performing a heat exchange between the capturing coolant discharged from the chiller and the flue gas
Data Source
AI summary
A carbon dioxide capturing apparatus using cold heat of liquefied natural gas (LNG) includes a heat exchanger to cool primary coolant using heat exchange between the primary coolant and the LNG; a chiller connected to the heat exchanger and configured to discharge capturing coolant colder than the primary coolant by performing a heat exchange between the capturing coolant and a cooling material; and a capturing cooler configured to capture carbon dioxide contained in flue gas by performing a heat exchange between the capturing coolant discharged from the chiller and the flue gas. A power generation system includes an LNG storage facility; a power generation facility discharging flue gas; a unit for heat exchange between the LNG and a coolant to regasify the LNG and cool the coolant; and a unit for capturing carbon dioxide contained in the flue gas by heat exchange between the discharged flue gas and the coolant.