Membrane-Based Thermochemical Reactor for High-Density Energy Storage
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing absorption-based thermochemical energy storage systems face limitations in energy storage density, charging temperature, and capital cost due to large reactor sizes and separated solution/refrigerant flows, which constrain their efficiency and flexibility.
Innovation Solution
A microchannel membrane-based reactor is introduced, featuring a porous membrane that allows vapor molecules to pass through while restricting absorbent molecules, enabling a compact, high-specific-surface-area design that integrates solution and refrigerant flows, and allows for direct diffusion of water molecules to lower charging temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional immersed or falling-film reactors are used, then the system structure is simple, but the absorption rate is limited and energy storage density is low
Solution Approach 1:
The invention transitions from conventional 2D heat and mass transfer interfaces (immersed or falling-film reactors) to a 3D microchannel network integrated with porous membrane. This dimensional enhancement creates extensive internal surface area within a compact volume, dramatically increasing the absorption rate while maintaining a manageable structural footprint through standardized module assembly.
Solution Approach 2:
The invention employs porous membrane as a core component that provides high specific surface area for heat and mass transfer. The porous structure enables simultaneous solution flow and refrigerant vapor diffusion through the same component, achieving high absorption rates without requiring complex multi-chamber configurations. The porous material inherently combines separation and transfer functions in a single element.
2Quantity of substance
If large reactor sizes are used, then the system can store more energy, but the energy storage density decreases and capital cost increases
Solution Approach 1:
The invention implements nested microchannels within the porous membrane structure, where refrigerant vapor channels are embedded inside the membrane matrix while solution flows through external passages. This nesting arrangement maximizes the heat and mass transfer interface area within the available volume, achieving high energy storage capacity without proportionally increasing reactor size. The modular design allows scaling capacity by adding parallel units rather than expanding single-unit volume.
3Productivity
If high charging temperatures are used, then the thermochemical reaction proceeds faster, but low-grade thermal energy cannot be utilized
Solution Approach 1:
The porous membrane structure provides extremely high specific surface area that compensates for the lower driving force at reduced temperatures. The enhanced surface area maintains sufficient reaction rate even when operating with low-grade thermal energy at lower temperatures. This allows the system to utilize waste heat and solar thermal energy that would otherwise be insufficient for conventional high-temperature thermochemical storage.
Solution Approach 2:
The invention changes the critical parameter from temperature to surface area. By dramatically increasing the heat and mass transfer surface area through microchannel and porous membrane integration, the system decouples reaction rate from temperature dependence. This parameter substitution enables efficient operation at lower temperatures where low-grade thermal energy sources become viable.
4Productivity
If solution and refrigerant flows are separated, then the system design is straightforward, but the energy storage efficiency is reduced
Solution Approach 1:
The invention merges solution flow and refrigerant vapor transport functions into a single integrated porous membrane component. The membrane simultaneously conducts liquid solution through its pores while allowing refrigerant vapor to diffuse through the same porous structure. This consolidation eliminates the need for separate channels and heat exchangers, improving energy storage efficiency through direct contact and enhanced mass transfer while maintaining design simplicity through modular assembly.
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 configuration enhances energy storage density, efficiency, and reduces capital costs by enabling high-density, low-temperature energy storage with improved heat/mass transfer and absorption/desorption rates, outperforming conventional systems.
Implementation Method 1
A porous membrane is positioned between the refrigerant channel and the solution channel; the porous membrane permits flow of vapor molecules therethrough while restricting flow of absorbent molecules
Implementation Method 2
the porous membrane permits flow of vapor molecules therethrough while restricting flow of absorbent molecules
Implementation Method 3
direct diffusion of water molecules through the membrane makes it possible to lower the required charging temperatures
Implementation Method 4
an absorbent-containing solution flowing therethrough
Implementation Method 5
Thermal energy storage may be considered as temporarily maintaining thermal energy in the form of hot or cold substances, phase changes of phase change materials, or chemical reactions
Data Source
AI summary
A thermochemical energy storage system. The system includes a membrane-based thermochemical reactor having a solution channel having an absorbent-containing solution flowing therethrough and a refrigerant channel having a refrigerant flowing therethrough along with first and second fluid channels. A porous membrane is positioned between the refrigerant channel and the solution channel; the porous membrane permits flow of vapor molecules therethrough while restricting flow of absorbent molecules. The system further includes a solution storage repository in fluid communication with the solution channel and a refrigerant repository in fluid communication with the refrigerant channel. The system can be used in high-density, high-efficiency, and low-temperature energy storage systems. The membrane-based reactor offers a large specific surface area and integrates solution/refrigerant flows, which enables formation of a highly compact reactor exhibiting strong heat/mass transfer. In some embodiments, direct diffusion of water molecules through the membrane makes it possible to lower the required charging temperatures.