Azole-Base CO2 Absorbent Composition for Low-Energy Regeneration

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Solution Overview

Problem

Existing carbon dioxide capture processes using absorbent solutions require significant energy consumption for regeneration, leading to high operating costs.

Innovation Solution

A carbon dioxide absorbing composition comprising an association of bases such as carbonates, hydrogen carbonates, and/or hydroxides with azole compounds in an aqueous solvent, allowing for efficient CO2 capture and easier regeneration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If traditional absorbent solutions (alkanolamines) are used for CO2 capture, then CO2 absorption capacity is achieved, but energy consumption for regeneration becomes very high

Engineering Contradiction:
ImproveCO2 absorption capacityVSAvoidenergy consumption for regeneration
Core Design Contradiction:
Quantity of substanceVSUse of energy by moving object

Solution Approach 1:

The patent uses a composite absorbent system combining an azole compound (such as imidazole or triazole) with a carbonate or hydroxide base. This composite approach creates a synergistic effect where the azole provides high CO2 absorption capacity through carbamate formation, while the carbonate/hydroxide enables easier regeneration at lower temperatures, thus resolving the contradiction between absorption capacity and regeneration energy consumption

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The invention changes the chemical parameters of the absorbent system by introducing azole compounds with specific pKa values and basicity characteristics. This parameter modification allows the system to achieve both high CO2 loading capacity and lower regeneration temperature requirements, directly addressing the energy consumption issue while maintaining absorption effectiveness

Inventive Principle:
Principle #35Parameter changes

2Productivity

If aqueous alkanolamine solutions are used, then CO2 capture is effective, but operating costs increase due to high energy requirements

Engineering Contradiction:
ImproveCO2 capture efficiencyVSAvoidoperating cost
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The patent modifies the chemical composition parameters by replacing traditional alkanolamines with azole-based systems that have favorable thermodynamic properties. This change reduces the heat of absorption and enables regeneration at lower temperatures, thereby reducing energy losses and operating costs while maintaining high CO2 capture productivity

Inventive Principle:
Principle #35Parameter changes

3Ease of manufacture

If hot alkali metal carbonate solutions are used as an alternative, then CO2 absorption occurs via inorganic carbonate reaction, but the system complexity and operational constraints increase

Engineering Contradiction:
Improvesimplicity of absorbent preparationVSAvoidsystem operational constraints
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent combines organic azole compounds with inorganic carbonate or hydroxide bases to create a composite system that integrates the advantages of both approaches. The azole provides ease of preparation and handling similar to organic solvents, while the inorganic base component maintains effective CO2 absorption, thereby reducing system complexity and operational constraints compared to using hot alkali metal carbonate solutions alone

Inventive Principle:
Principle #40Composite materials

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 composition achieves high CO2 capture capacity with reduced energy requirements for regeneration, compared to traditional methods, thereby lowering operational costs.

Implementation Method 1

The absorbed CO2 reacts with the alkanolamine in solution via a reversible exothermic reaction... The principle is based on the absorption of CO2 in the aqueous solution by an inorganic carbonate via a reaction leading to an inorganic hydrogen carbonate

Methodology Applied
Scientific EffectChemical reaction (reversible): Chemical Bonding

Implementation Method 2

the reaction involved is the reaction of the figure 1 (at the top) which involves carbamate, hydrogen carbonate and carbonate ions

Methodology Applied
Scientific EffectChemical reaction (reversible exothermic): Exothermic Reaction

Implementation Method 3

regeneration by the reversible reaction transforming an inorganic hydrogen carbonate into an inorganic carbonate

Methodology Applied
Scientific EffectReversible reaction: Chemical Bonding

Data Source

PatentEP4363080B1Absorbent aqueous composition containing a base and an azole for separating carbon dioxide from a gaseous effluent
Publication Date: 2025.12.03 IFP ENERGIES NOUVELLES
  • EP4363080B1 patent drawingFigure 1~2
  • EP4363080B1 patent drawingFigure 3~4
  • EP4363080B1 patent drawingFigure 5~6

AI summary

The present invention relates to a composition for absorbing carbon dioxide contained in a gaseous effluent, the composition comprising the combination of a base B or a mixture of bases B of the carbonate, hydrogen carbonate or hydroxide type with at least one unsaturated heterocyclic organic compound R(NH)n, where the group R is an alicyclic, mono- or polyaromatic or heterocyclic group having at least one nitrogen atom, and n is between 1 and 20, in an aqueous solvent Z and/or the product obtained by reacting said base B or said mixture of bases B with said compound R(NH)n in said aqueous solvent Z. The invention also relates to a method for capturing CO2 in a gaseous effluent using said composition.