Integrated LNG and Power System with CO2 Capture for Energy Storage
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Solution Overview
Problem
Existing systems for managing excess electric power and natural gas supply face inefficiencies and high costs due to the discontinuity of renewable energy sources, limited storage capacity, and environmental impact, particularly in the use of liquefied natural gas (LNG) and LAES systems.
Innovation Solution
A process that accumulates excess electric power by producing and storing liquefied natural gas, separating and liquefying carbon dioxide, and generating power through a combination of heat exchanges and combustion processes, utilizing available electric power and liquefied oxygen to enhance efficiency and storage capacity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If liquefied natural gas (LNG) is used for energy storage and power generation, then energy storage capacity is improved, but environmental harm increases due to greenhouse gas emissions from non-renewable sources
Solution Approach 1:
The system changes the thermodynamic parameters of natural gas by liquefying it during off-peak periods and vaporizing it during peak demand. This phase change enables energy storage while the patent addresses emissions by capturing CO2 from the combustion process and injecting it into depleted gas reservoirs, thus storing energy without releasing harmful gases into the atmosphere.
Solution Approach 2:
The patent converts the harmful CO2 emissions from natural gas combustion into a beneficial resource by capturing the CO2 and injecting it into depleted gas reservoirs for geological storage. This transforms the waste product into a solution for both emission reduction and reservoir pressure maintenance, enabling continued use of natural gas for energy storage without environmental harm.
2Quantity of substance
If compressed air energy storage (CAES) systems are used to accumulate excess electric power, then energy accumulation capacity is improved, but system complexity increases due to multiple processing steps
Solution Approach 1:
The patent merges multiple functions into a single integrated system: natural gas liquefaction for energy storage, CO2 capture from combustion, and geological injection for both emission storage and reservoir pressure maintenance. This consolidation reduces system complexity compared to separate CAES, LAES, and carbon capture systems operating independently.
Solution Approach 2:
The depleted gas reservoir serves multiple functions simultaneously: it stores CO2 emissions, maintains pressure for future gas production, and acts as the termination point for the energy storage cycle. This multi-functionality reduces the need for separate infrastructure components, thereby reducing overall system complexity.
3Quantity of substance
If liquid air energy storage (LAES) is used for large-scale energy storage, then energy storage capacity is improved, but energy efficiency decreases due to high energy cost of producing liquid air
Solution Approach 1:
The system uses the natural gas itself as the working fluid for energy storage, eliminating the need to produce liquid air from atmospheric nitrogen. The natural gas is liquefied during off-peak periods using excess renewable energy and vaporized during peak demand, with the phase change providing the necessary energy storage mechanism without the high energy costs associated with air liquefaction.
Solution Approach 2:
The patent utilizes the phase change parameters of natural gas (liquefaction and vaporization) as the basis for energy storage, avoiding the need to change the composition or properties of the working fluid. This approach is more energy-efficient than LAES because it leverages the inherent properties of the stored fuel rather than requiring continuous processing of atmospheric air.
4Reliability
If exhausted wells are used for gas accumulation, then storage capacity is improved, but storage volume is limited with respect to current demands
Solution Approach 1:
The system performs preliminary liquefaction of natural gas during off-peak periods when renewable energy production exceeds demand. By storing the gas in liquid form in above-ground tanks, the system prepares the energy carrier for later use without being constrained by the limited capacity of subsurface exhausted wells, thereby increasing overall storage volume while maintaining reliability.
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
Simultaneously stabilizes both gas and electric distribution networks, achieves efficient energy storage with CO2 sequestration, and reduces environmental impact by integrating renewable energy sources.
Implementation Method 1
a flow of combusted gas is expanded in an expander with power production and is then cooled in a heat exchanger
Implementation Method 2
a flow of combusted gas is produced from the combustion of natural gas
Implementation Method 3
a flow of combusted gas is expanded in an expander with power production
Implementation Method 4
there is a step of cooling, dehydration and liquefaction of carbon dioxide
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
The present invention describes an integrated system for generating power and vaporizing liquefied natural gas with reduced CO2 emissions into the atmosphere.