CO2 Liquefaction Method for Direct Air Capture Without Buffer Storage
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Solution Overview
Problem
Existing methods for removing CO2 from dilute sources like air are inefficient, as they fail to fully recover CO2, require expensive buffer storage, and do not effectively separate entrained air from the CO2 product.
Innovation Solution
A method involving a CO2-removal unit followed by liquefaction, which separates a liquefied CO2 stream from a gaseous stream containing nitrogen, oxygen, and CO2, allowing for CO2 concentration beyond 90 vol. % and eliminating the need for gaseous buffer storage, with the option to recycle the gaseous stream for further CO2 enrichment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If CO2 is removed from dilute sources like air using existing methods, then CO2 removal is achieved, but CO2 recovery is incomplete and expensive buffer storage is required
Solution Approach 1:
The patent applies phase transition by liquefying the CO2-enriched stream to separate CO2 from entrained air. The CO2 is converted from gaseous to liquid phase, enabling effective separation and eliminating the need for buffer storage while achieving complete CO2 recovery from dilute sources.
Solution Approach 2:
The patent extracts CO2 from the CO2-enriched stream by liquefaction, separating it from the gaseous stream containing nitrogen, oxygen, and residual CO2. This extraction process achieves complete CO2 recovery without requiring buffer storage infrastructure.
2Manufacturing precision
If CO2 is purified in downstream processes, then CO2 purity is improved, but CO2 recovery from air is not maximized
Solution Approach 1:
The patent uses phase transition during liquefaction to achieve both high CO2 purity (beyond 90 vol.%, even beyond 95 vol. % or even beyond 99 vol. %) and complete CO2 recovery from air, eliminating the trade-off between purity and recovery extent.
3Adaptability or versatility
If buffer storage of CO2 product is implemented, then intermittent operation is enabled, but operational cost increases significantly
Solution Approach 1:
The patent eliminates the need for buffer storage by implementing continuous liquefaction of CO2-enriched streams. The phase transition process enables CO2 to be continuously converted to liquid form for removal, allowing intermittent operation without expensive buffer storage infrastructure.
4Reliability
If CO2 removal systems are designed for continuous operation, then operational stability is improved, but system complexity and cost increase
Solution Approach 1:
The patent applies phase transition in a straightforward liquefaction process that can operate continuously or intermittently without complex buffer storage systems. The liquefaction unit provides operational stability through continuous CO2 removal while maintaining simplicity in system design.
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 method achieves high CO2 recovery and purity without continuous operation, minimizing losses during purification and eliminating the need for expensive buffer storage, while allowing for non-continuous CO2 removal and improved recovery efficiency.
Implementation Method 1
liquefying the first CO2-enriched stream obtained in step b) in a liquefaction unit
Implementation Method 2
removing CO2 from the CO2-containing stream provided in step a) in a first CO2-removal unit
Implementation Method 3
removing CO2 from the CO2-containing stream provided in step a) in a first CO2-removal unit
Data Source
AI summary
The present invention relates to a method for removing carbon dioxide (CO2) from a CO2-containing stream, the method at least comprising the steps of: a) providing a CO2-containing stream (10), preferably air wherein the CO2-containing stream (10) has a CO2 content in the range of from 10 to 1000 ppmv, preferably from 100 to 1000 ppmv; b) removing CO2 from the CO2-containing stream (10) provided in step a) in a first CO2 removal unit (2), thereby obtaining a first CO2-enriched stream (30) and a first CO2-depleted stream (20); c) liquefying the first CO2-enriched stream (30) obtained in step b) in a liquefaction unit (3); d) removing from the liquefaction unit (3) at least a liquefied CO2 stream (40) and a gaseous stream (15) containing at least nitrogen [N2 (g)], oxygen [O2 (g)] and CO2 (g).