Alkylamino Alkyloxy Ether Absorbent for Selective H2S Removal

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Solution Overview

Problem

Current methods for selectively removing hydrogen sulfide (H2S) from gas mixtures containing CO2 are inefficient, especially at low H2S partial pressures, leading to high CO2 removal and material losses due to volatility issues with existing amine solutions.

Innovation Solution

A catalytically synthesized alkylaminoalkyloxy alkyl ethers are used as absorbents, produced by reacting alkyloxy alcohol ethers with alkyl amines, which resist cyclization and are effective in selectively absorbing H2S from gas mixtures containing CO2, with improved selectivity and capacity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional amine solutions are used for acid gas removal, then both CO2 and H2S are removed simultaneously, but selective H2S removal is achieved with high CO2 removal as a trade-off

Engineering Contradiction:
Improveselectivity of H2S removalVSAvoidCO2 removal amount
Core Design Contradiction:
Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent modifies the chemical structure of amine absorbents by introducing alkylaminoalkyloxy groups with specific molecular weights and branching patterns. This structural parameter change reduces the amine's reactivity toward CO2 while maintaining high H2S absorption capacity, achieving selective H2S removal with minimal CO2 co-removal.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates composite amine structures combining sterically hindered amino groups with specific alkyloxy ether chains. This composite structure provides both high H2S selectivity and reduced CO2 reactivity, resolving the contradiction between selective H2S removal and minimizing CO2 removal.

Inventive Principle:
Principle #40Composite materials

2Productivity

If sterically hindered amines are used to achieve nearly complete removal of acid gases, then H2S and CO2 removal efficiency is improved, but the process becomes suitable only for low partial pressure applications

Engineering Contradiction:
Improveacid gas removal efficiencyVSAvoidapplicability range of partial pressures
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The patent adjusts the steric hindrance parameters of the amine structure by varying the alkyl group size and position, as well as the alkyloxy chain length. This optimization allows the absorbent to maintain high removal efficiency across a broader range of partial pressures, including high CO2 partial pressure conditions.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If primary and secondary amines are used for H2S absorption, then H2S and CO2 absorption capacity is improved, but CO2 reacts readily to form carbamates reducing H2S selectivity

Engineering Contradiction:
Improveabsorption capacityVSAvoidH2S selectivity
Core Design Contradiction:
Quantity of substanceVSManufacturing precision

Solution Approach 1:

The invention changes the amine type from primary or secondary to sterically hindered tertiary amines with specific alkylaminoalkyloxy structures. This structural modification reduces the tendency to form carbamates with CO2 while maintaining high H2S absorption capacity through the basic amino group.

Inventive Principle:
Principle #35Parameter changes

4Manufacturing precision

If existing amine solutions are used for gas scrubbing, then H2S removal is achieved, but material losses occur due to volatility and regeneration requirements

Engineering Contradiction:
ImproveH2S removal effectivenessVSAvoidamine material loss
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent modifies the physical parameters of the amine solution by introducing heavier alkyloxy ether chains with higher molecular weights. This increases the boiling point and reduces volatility of the amine, thereby minimizing material losses during operation and regeneration while maintaining H2S removal effectiveness.

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 absorbents exhibit high selectivity and loading capacity for H2S, maintaining effectiveness even after regeneration, and reduce material losses and operational costs by minimizing CO2 absorption and volatility issues.

Implementation Method 1

the absorbents exhibit high selectivity and loading capacity for H2S, maintaining effectiveness even after regeneration

Methodology Applied
Scientific EffectSelective absorption: Absorption (physical)

Implementation Method 2

The amine usually contacts the acidic gases and the liquids as an aqueous solution containing the amine in an absorber tower

Methodology Applied
Scientific EffectChemical reaction with acidic gases: Chemical Bonding

Implementation Method 3

A catalytically synthesized alkylaminoalkyloxy alkyl ethers are used as absorbents, produced by reacting alkyloxy alcohol ethers with alkyl amines

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentEP1919855B1Alkylamino alkyloxy (alcohol) monoalkyl ether for acid gas scrubbing process
Publication Date: 2014.08.20 EXXONMOBIL TECHNOLOGY & ENGINEERING CO
  • EP1919855B1 patent drawingFigure 1
  • EP1919855B1 patent drawingFigure 2
  • EP1919855B1 patent drawingFigure 3

AI summary

An acid gas absorbent comprising an alkylamino alkyloxy (alcohol) monoalkyl ether and a process for the selective removal Of H2S from gaseous mixtures containing H2S and CO2 using an absorbent solution comprising an alkylamino alkyloxy alcohol monoalkyl ether.