Hindered Amine Absorbing Liquid for Low-Temperature CO2 Capture
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Solution Overview
Problem
Current methods for capturing carbon dioxide from gases are energy-intensive and inefficient, requiring high temperatures for desorption and regeneration, which limits their practical application due to high energy consumption and material corrosion issues.
Innovation Solution
An absorbing liquid comprising specific alkanolamines, low-molecular-weight diol compounds, and water is used to improve desorption rates and regeneration efficiency at lower temperatures, allowing for efficient carbon dioxide capture with reduced energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If aqueous solutions of primary amines such as monoethanolamine are used as absorbing liquid, then carbon dioxide absorption capacity is improved, but material corrosion increases and energy consumption increases
Solution Approach 1:
The patent changes the chemical structure parameters of the amine by introducing hindered amine structures (specifically 2-isopropylaminoethanol and 2-isobutylaminoethanol) with branched alkyl groups. This structural modification reduces the corrosiveness while maintaining CO2 absorption capacity, resolving the contradiction between absorption capacity and material corrosion.
Solution Approach 2:
The patent uses a composite absorbing liquid formulation containing multiple amine components (hindered amines combined with other amine types) in specific ratios. This composite approach leverages the advantages of each component to achieve both high CO2 absorption capacity and reduced corrosion, while also optimizing the energy required for desorption.
2Quantity of substance
If aqueous solutions of alkanolamines are used for carbon dioxide capture, then carbon dioxide absorption is improved, but energy consumption increases due to high temperature requirement for desorption
Solution Approach 1:
The patent modifies the chemical parameters of the amine structure by using hindered amines with specific molecular configurations. This structural change alters the thermodynamic properties of the absorbing liquid, enabling effective CO2 desorption at lower temperatures (60-90°C) and significantly reducing the energy consumption for the regeneration process while maintaining high absorption capacity.
3Temperature
If non-aqueous organic compounds such as alcohol are used as solvent, then specific heat is reduced and low-temperature desorption is improved, but carbon dioxide absorption efficiency decreases and cooling energy is required
Solution Approach 1:
The patent creates a composite absorbing liquid system that combines water with hindered amine compounds. This composite formulation maintains the high specific heat capacity of water for effective heat management while the hindered amine components provide high CO2 absorption efficiency and enable low-temperature desorption, thus resolving the contradiction between absorption efficiency and desorption temperature.
Solution Approach 2:
The patent changes the physical-chemical parameters of the absorbing liquid by selecting specific hindered amine structures with optimized molecular weights and functional groups. These parameter changes enable the liquid to achieve both high CO2 absorption capacity and low-temperature desorption capability without requiring additional cooling energy, overcoming the limitations of using pure alcohols.
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 solution enables carbon dioxide to be desorbed at lower temperatures, reducing energy costs and allowing the use of low-grade waste heat, resulting in a more efficient and cost-effective method for capturing carbon dioxide.
Implementation Method 1
a method for absorbing carbon dioxide by bringing a carbon dioxide-containing gas into contact with an aqueous solution of an alkanolamine in an absorption tower
Implementation Method 2
The absorbed carbon dioxide is typically desorbed and regenerated by heating the absorbing liquid to about 120° C. in a regeneration tower
Data Source
AI summary
Disclosed is an absorbing liquid for separating and capturing carbon dioxide from a carbon dioxide-containing gas, the absorbing liquid containing: at least one alkanolamine represented by formula (1)wherein R1 represents hydrogen or C1-4 alkyl, R2 and R3 are identical or different and each represent hydrogen or C1-3 alkyl, R1, R2, and R3 are not all hydrogen, and n is 1 or 2; a low-molecular-weight diol compound and/or glycerin; and water.