Amine-Modified Siloxane Membranes for Low-Energy CO2 Capture
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Solution Overview
Problem
Existing technologies for direct air capture of carbon dioxide are inefficient and energy-intensive, particularly in capturing and transforming CO2 from ambient air into valuable resources.
Innovation Solution
A hybrid carbon dioxide capture and transformation system using functionalized siloxane membranes modified with amines and ammonium groups, which are cross-linked to increase CO2 solubility and permselectivity, and a modular system with temperature, pressure, and vacuum adsorption-desorption cycles for efficient CO2 capture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing technologies are used for direct air capture of CO2, then CO2 capture can be achieved, but the process is inefficient and energy-intensive
Solution Approach 1:
The patent employs temperature swing adsorption (TSA) by cycling the sorbent between adsorption and desorption states through temperature changes. During adsorption, the sorbent captures CO2 at ambient conditions, and during desorption, heating releases concentrated CO2 and regenerates the sorbent. This parameter-based cyclic operation enables efficient CO2 capture and concentration while reducing energy consumption compared to continuous high-energy processes.
Solution Approach 2:
The invention uses composite sorbent materials combining amine-functionalized materials with porous supports. The amine functional groups provide high CO2 selectivity through chemical interaction, while the porous support structure enhances surface area and mass transfer. This composite approach achieves high capture efficiency at lower energy input by leveraging the synergistic effects of chemical affinity and physical structure.
2Productivity
If single-stage separation process is used, then the system is simpler, but CO2 flux and permeate concentration are lower
Solution Approach 1:
The patent implements multi-stage separation processes where CO2 capture is divided into multiple sequential stages. Each stage uses sorbent beds operating in alternating adsorption-desorption cycles, with intermediate CO2 concentration steps. This segmentation allows progressive enrichment of CO2, achieving higher flux and permeate concentration (>99.9%) by breaking down the separation task into manageable stages rather than attempting single-stage high-concentration separation.
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 system achieves high CO2 capture efficiency, with permeate concentrations exceeding 99.9% and energy-efficient operation across varying CO2 concentrations and pressures, suitable for applications like space exploration and HVAC system retrofits.
Implementation Method 1
The CO2 capture process can include a thermal system packed with sorbents such as amine-based sorbents and can include temperature, pressure, vacuum adsorption-desorption cycles for CO2 capture
Implementation Method 2
The functionalized siloxane membranes can be modified with primary, secondary, tertiary amines or any combination thereof to provide CO2 binding and regeneration
Data Source
AI summary
An additive-modified membrane includes a functionalized siloxane and an additive that modifies the structure of the functionalized siloxane. The functionalized siloxane is cross-linked. The additive-modified membrane is configured to capture gas molecules, the additive increases a solubility of the gas molecules in the additive-modified membrane, and increasing the solubility of the gas molecules in the additive-modified membrane includes increasing the permselectivity of the additive-modified membrane. A CO2 capture system including the additive-modified membrane in contact with a CO2 absorbent is configured to capture CO2 from an atmosphere.