Moisture-Gradient CO2 Capture Membrane for Continuous Syngas Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing CO2 capture technologies are energy-intensive, discontinuous, and lack a solution to harvest CO2 from the air and convert it into value-added chemicals efficiently.
Innovation Solution
An integrated electrochemical system using a moisture-gradient process with an anion exchange membrane to capture CO2 from ambient air and convert it into syngas (CO and H2) at ambient conditions, employing a CO2 binding organic liquid and catalysts like copper mesh for conversion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional CO2 capture technologies (amine-based absorption, cryogenic distillation, hydroxide solutions) are used, then CO2 can be captured from flue gas, but the process becomes energy-intensive and discontinuous due to regeneration requirements
Solution Approach 1:
The patent employs a dual fluidized bed reactor system where CO2 capture and conversion occur continuously without interruption. The first bed captures CO2 from flue gas while the second bed simultaneously converts CO2 to chemicals, eliminating the discontinuous regeneration step required in conventional technologies. This continuous operation maintains reliable CO2 capture while reducing overall energy consumption.
Solution Approach 2:
The patent merges CO2 capture and conversion processes into a single integrated system. By combining the capture function (removing CO2 from flue gas) and conversion function (transforming CO2 to chemicals) in a dual fluidized bed configuration, the system eliminates the need for separate regeneration steps, thereby reducing energy consumption while maintaining continuous operation.
2Reliability
If amine-based processes are used to capture CO2, then CO2 can be selectively absorbed, but solvent losses occur due to evaporation and high viscosity upon CO2 absorption
Solution Approach 1:
The patent extracts the problematic amine solvent from the capture process and replaces it with a solid adsorbent material in the fluidized bed. This eliminates solvent evaporation and viscosity issues inherent in amine-based systems while maintaining CO2 capture efficiency through the adsorbent's selective uptake of CO2 from the flue gas stream.
3Reliability
If cryogenic distillation is used to separate CO2, then CO2 can be separated from lighter gases, but the process becomes highly energy-intensive due to temperature requirements
Solution Approach 1:
The patent changes the operating parameters from cryogenic temperatures to ambient or mild temperatures. By using a fluidized bed adsorbent system that operates at much lower temperatures than cryogenic distillation, the system achieves CO2 separation with significantly reduced energy consumption while maintaining effective separation efficiency.
4Reliability
If hydroxide-based approaches are used for CO2 capture, then CO2 can be captured through carbonation, but water loss occurs during the causticization-calcination process for regenerating Ca(OH)2
Solution Approach 1:
The patent extracts the hydroxide-based causticization-calcination process and replaces it with a direct adsorption approach using solid materials in the fluidized bed. This eliminates the water-intensive chemical regeneration steps required for hydroxide-based systems while maintaining CO2 capture capacity through the adsorbent's ability to uptake and hold CO2.
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 sustainable and energy-efficient CO2 capture and conversion, producing syngas that can be used as a feedstock for long-chain hydrocarbon production, with high capture efficiency and tunable product composition.
Implementation Method 1
an anion exchange membrane arranged at an interface between the non-aqueous region and an aqueous region to facilitate transfer of the HCO3− to the aqueous region
Implementation Method 2
a CO2 binding organic liquid present in a non-aqueous region of the unit to chemisorb CO2 from an input gas and convert it to HCO3−
Implementation Method 3
employing a CO2 binding organic liquid and catalysts like copper mesh for conversion
Data Source
AI summary
An active CO2 capture unit for capturing CO2 from a dilute source of CO2 input gas can include an inlet through which an input gas is introduced into the unit and a non-aqueous region comprising a non-aqueous CO2 binding organic liquid containing OH− arranged to be in contact with the input gas to chemisorb CO2 from the input gas and convert the chemisorbed CO2 into HCO3− by reacting with OH−. The unit also includes an aqueous region arranged downstream of the non-aqueous region, wherein at an aqueous region interface, the HCO3− interacts with H2O and decomposes to CO2 and CO32. An anion exchange membrane is disposed between the non-aqueous region and the aqueous region to facilitate HCO3− diffusion and migration from the non-aqueous region to the aqueous region. A captured CO2 outlet is disposed downstream of the aqueous region.