Combination Rotary Pre-Drying for Climate-Ready CO2 Capture

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Solution Overview

Problem

Existing carbon capture technologies face challenges such as material degradation, high energy consumption, and the need for complex and expensive protective measures due to the use of amine-based chemisorbents, and physisorbents require pre-drying which is structurally and energy-intensive, limiting their application to specific climate zones.

Innovation Solution

A device and method utilizing a rotatable pre-drying unit with physisorbents for water adsorption, combined with a decoupled system of drying and CO2 units, allowing for efficient moisture removal and CO2 capture without the need for pre-drying, using sorption wheels or heat exchangers with layered sorbents like silica gel and zeolite, and heat recovery systems to optimize energy use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If amine-based chemisorbents are used for CO2 capture, then CO2 capture efficiency is improved, but material degradation occurs due to oxidation at temperatures above 60°C

Engineering Contradiction:
ImproveCO2 capture efficiencyVSAvoidmaterial stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent changes the chemical composition parameter by switching from amine-based chemisorbents to physisorbent materials (such as metal organic frameworks, covalent organic frameworks, or activated carbon) that operate via physical adsorption rather than chemical absorption. This parameter change allows the system to achieve CO2 capture efficiency while avoiding the oxidation degradation issue inherent in amine-based materials at elevated temperatures.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite sorbent materials combining multiple components (e.g., metal organic frameworks with covalent organic frameworks, or composite activated carbon structures) that leverage the advantages of each material while mitigating their individual limitations. These composite physisorbent materials provide both high CO2 capture capacity and thermal stability without the degradation problems of amine-based chemisorbents.

Inventive Principle:
Principle #40Composite materials

2Reliability

If physisorbents are used for CO2 capture, then material stability is improved, but pre-drying is required which increases structural complexity and energy consumption

Engineering Contradiction:
Improvematerial stabilityVSAvoidpre-drying system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and removes the pre-drying system from the overall CO2 capture process configuration. By developing physisorbent materials with inherent hydrophobic properties or surface modifications that prevent water adsorption competition, the system eliminates the need for separate pre-drying units, thereby reducing structural complexity while maintaining material stability.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent designs the sorbent material to perform multiple functions simultaneously: CO2 adsorption, water resistance, and thermal stability. The physisorbent materials are engineered to selectively adsorb CO2 while rejecting water molecules, eliminating the need for separate pre-drying functionality and integrating multiple performance requirements into a single component.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Manufacturing precision

If pre-drying is implemented using physisorbents, then CO2 capture purity is improved, but energy consumption increases

Engineering Contradiction:
ImproveCO2 capture purityVSAvoidenergy consumption
Core Design Contradiction:
Manufacturing precisionVSUse of energy by moving object

Solution Approach 1:

The patent changes the operational parameters by using physisorbent materials with optimized pore sizes, surface areas, and hydrophobic characteristics that enable direct CO2 adsorption from moist air without requiring pre-drying. This parameter change maintains CO2 capture purity while eliminating the energy-intensive pre-drying process.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the presence of water vapor in ambient air from a harmful factor that competes with CO2 adsorption into a beneficial condition. The physisorbent materials are designed to selectively adsorb CO2 even in the presence of water vapor, utilizing the humidity as a natural condition rather than requiring its removal, thereby maintaining purity while reducing energy consumption.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Adaptability or versatility

If physisorbents are used in polar regions, then CO2 capture is enabled, but application is limited due to lower water content in air

Engineering Contradiction:
Improveclimate adaptabilityVSAvoidCO2 capture efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent adjusts the operational parameters of the physisorbent system for polar climate conditions by modifying the sorbent material properties (such as pore size distribution, surface chemistry, and thermal characteristics) to optimize performance at lower temperatures and lower humidity levels. This parameter change enables the system to maintain CO2 capture efficiency in polar regions where ambient conditions differ significantly from temperate zones.

Inventive Principle:
Principle #35Parameter changes

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 efficient CO2 capture with high purity and reduced energy consumption, enabling operation across various climates without the need for pre-drying, and allows for the reuse of sorbents, thus enhancing the efficiency and cost-effectiveness of carbon capture.

Implementation Method 1

at least one rotatable pre-drying unit comprising at least one sorbent for the physisorption of water

Methodology Applied
Scientific EffectPhysisorption: Physisorption

Implementation Method 2

at least one sorbent for the physisorption of water

Methodology Applied
Scientific EffectAdsorption: Adsorption

Data Source

PatentEP4606456A1Combination rotary pre-drying unit with co2 recovery
Publication Date: 2025.08.27 VOLKSWAGEN AG
  • EP4606456A1 patent drawingFigure 1~2
  • EP4606456A1 patent drawingFigure 3
  • EP4606456A1 patent drawingFigure 4~4a

AI summary

The present invention describes a device for extracting carbon dioxide from a gaseous medium, comprising: a first air flow channel for the gaseous medium, a second air flow channel for exhaust air from the device, and at least one rotatable pre-drying unit comprising at least one sorbent for the physisorption of water. The at least one rotatable pre-drying unit is axially rotatably driven and the first air flow channel radially controls the at least one rotatable pre-drying unit. Furthermore, a method for extracting carbon dioxide and the use of the device and the method are disclosed.