CO2 Geothermal Circulation Using Natural Reservoir Pathways
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional renewable energy systems, such as wind and solar, face limitations due to high costs and inefficiencies, and geothermal systems require high temperatures and large-scale hydrofracturing, which can have adverse environmental impacts.
Innovation Solution
A carbon dioxide-based geothermal energy system that utilizes injection and production wells without large-scale hydrofracturing, using supercritical carbon dioxide as a working fluid to extract thermal energy from underground reservoirs at lower temperatures, converting it into electricity or heat through an energy converting apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional geothermal systems use large-scale hydrofracturing to access reservoirs, then energy extraction capability is improved, but environmental harm and system complexity increase
Solution Approach 1:
The patent extracts the harmful hydrofracturing process from the geothermal system by utilizing pre-existing natural fractures and porous rock formations. The system accesses reservoirs through natural geological pathways rather than creating artificial fractures, thereby maintaining energy extraction capability while eliminating environmental harm associated with hydrofracturing.
Solution Approach 2:
The patent introduces carbon dioxide as an intermediary working fluid that circulates through natural reservoir pathways. This CO2-based system acts as a mediator between the heat source and power generation equipment, enabling energy extraction through natural convection and diffusion processes in porous media without requiring mechanical fracturing.
2Productivity
If conventional geothermal systems require high temperatures, then energy generation efficiency is improved, but location adaptability decreases
Solution Approach 1:
The patent changes the thermodynamic parameters of the working fluid by using carbon dioxide instead of water. CO2 maintains favorable thermodynamic properties at lower temperatures and pressures, allowing the system to operate efficiently in locations with moderate geothermal gradients. This parameter change enables energy generation in previously unsuitable locations while maintaining acceptable efficiency levels.
Solution Approach 2:
The patent utilizes phase transitions of carbon dioxide (between supercritical, gaseous, and liquid states) to drive the power generation cycle. These phase changes occur at relatively low temperatures compared to conventional water-based systems, enabling the system to extract energy from moderate-temperature reservoirs and expand its geographic applicability.
3Object-generated harmful factors
If carbon dioxide is used as working fluid for geothermal energy extraction, then environmental benefit through CO2 sequestration is improved, but system complexity increases
Solution Approach 1:
The patent assigns multiple functions to the carbon dioxide working fluid: it serves as both the heat transfer medium for energy extraction and the sequestration agent for carbon storage. This multi-functionality eliminates the need for separate CO2 injection and energy extraction systems, thereby reducing overall system complexity while achieving both energy generation and environmental benefits.
Solution Approach 2:
The patent merges the geothermal energy extraction process with carbon dioxide sequestration into a single integrated system. The CO2 circulation loop simultaneously performs heat extraction from reservoirs and permanent storage in deep geological formations, combining two environmental and energy objectives into one unified process that reduces operational complexity.
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 system provides a cost-effective, efficient, and environmentally friendly means of generating renewable energy while sequestering carbon dioxide, enabling energy production in a wider range of locations and reducing the carbon footprint, with potential for multiple applications including electricity generation and direct use.
Implementation Method 1
exposing the non-water based working fluid to the first temperature can produce heated non-water based working fluid
Implementation Method 2
thermal energy contained in the heated non-water based working fluid can be converted to electricity, heat, or combinations thereof
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Novel carbon dioxide-based geothermal energy generation systems, i.e., carbon plume geothermal (CPG) systems, and methods are provided. With the novel systems and methods described herein, geothermal energy can now be provided at lower temperatures and at locations other than hot, dry rock formations, without negatively impacting the surrounding area through use of large-scale hydrofracturing. Use of a carbon dioxide-based geothermal system further provides a means for sequestering and storing excess carbon dioxide, rather than having it released to the atmosphere.