Cyclic Diamine Acid Gas Absorbent for Durable CO2 Desorption
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Solution Overview
Problem
Conventional alkanolamines used for acid gas absorption, such as CO2, suffer from low durability and oxidation resistance, leading to deteriorating absorption characteristics over time, especially under high heating conditions, and require high energy for recovery.
Innovation Solution
An acid gas absorbent containing specific cyclic diamine compounds represented by Formulas (1a) and (1b), along with optional additional amine compounds (2), dissolved in a solvent like water, enhances absorption and desorption efficiency while maintaining oxidation durability and reducing energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional alkanolamines are used for acid gas absorption, then absorption function is provided, but durability and oxidation resistance are low causing deterioration over time
Solution Approach 1:
The patent uses a composite amine system combining cyclic carbamate-forming amine (20-60 mass%) and cyclic non-carbamate-forming amine (40-80 mass%) to achieve both high absorption performance and improved durability. The synergistic effect of the two amine components provides oxidation resistance while maintaining stable absorption characteristics over time.
Solution Approach 2:
The patent optimizes the concentration ratio and molecular structure parameters of the amine components to enhance durability. By controlling the mass% ratio of carbamate-forming to non-carbamate-forming amine and selecting specific cyclic structures, the system achieves improved oxidation resistance and long-term stability.
2Productivity
If heating temperature is increased for CO2 recovery from absorbent, then desorption efficiency is improved, but amine oxidation deteriorates
Solution Approach 1:
The composite amine system with non-carbamate-forming cyclic amine provides inherent oxidation resistance that protects the carbamate-forming amine during high-temperature desorption. This allows efficient CO2 recovery at elevated temperatures while minimizing amine degradation.
Solution Approach 2:
The patent converts the potential harm of high-temperature heating into a benefit by using the thermal stability of cyclic amines to enable efficient desorption while the cyclic structure's resistance to oxidation protects the system from degradation, thus turning a potentially harmful condition into an advantageous operating parameter.
3Use of energy by moving object
If energy consumption is reduced for acid gas recovery, then operational cost is lowered, but absorption capacity may be insufficient
Solution Approach 1:
The composite amine system achieves high acid gas absorption capacity through the synergistic interaction between carbamate-forming and non-carbamate-forming amines. The non-carbamate-forming amine enhances the overall absorption capacity while the system maintains lower heat of absorption, reducing the energy required for CO2 desorption and regeneration.
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 absorbent achieves high CO2 absorption rates with reduced energy consumption and improved durability, minimizing amine release and corrosion, allowing stable, long-term operation with enhanced treatment efficiency.
Implementation Method 1
a technique of separating and recovering a discharged acid gas is known... absorption methods... bringing exhaust gas generated when burning fossil fuel into contact with a chemical absorbent
Implementation Method 2
a step of absorbing carbon dioxide into an aqueous amine solution and a step of desorbing carbon dioxide from an aqueous solution that has absorbed carbon dioxide
Data Source
AI summary
Embodiments provide an amine compound having a large amount of an acid gas to be absorbed and strong oxidation resistance, an absorbent containing the amine compound, a method for removing an acid gas, and an acid gas removal apparatus.