Pressurized Water Absorption of Geothermal H2S and CO2

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Solution Overview

Problem

Conventional methods fail to effectively and environmentally friendly separate and dispose of hydrogen sulfide (H2S) and carbon dioxide (CO2) from geothermal non-condensable gas mixtures, which are rich in these gases and also contain other gases like H2, N2, CH4, and Ar, leading to environmental pollution and health hazards.

Innovation Solution

A method involving pressurization of the gas mixture to 6-20 bar and contacting it with a water stream at 8-23 bar to absorb H2S and CO2 into the water, followed by injection into a geological reservoir for mineralization, separating these gases from the other less soluble components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of substance

If conventional methods (burning, oxidizing, or mixing with water) are used to dispose of H2S and CO2, then the gases can be removed from the gas stream, but large amounts of water are required and environmental pollution remains

Engineering Contradiction:
Improvegas removal efficiencyVSAvoidwater consumption
Core Design Contradiction:
Loss of substanceVSQuantity of substance

Solution Approach 1:

The patent changes the pressure parameter by pressurizing the gas mixture to 6-20 bar before absorption, which increases the solubility of H2S and CO2 in the water stream, thereby reducing the quantity of water needed while maintaining effective gas removal

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses an amine-based absorbent solution as an intermediary medium that selectively absorbs H2S and CO2 from the gas stream under pressurized conditions, enabling more efficient gas removal with reduced water consumption compared to direct water mixing

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If H2S and CO2 are vented into the atmosphere to lower concentration near the power station, then immediate safety is improved, but long-term environmental pollution and health hazards increase

Engineering Contradiction:
Improveimmediate safetyVSAvoidenvironmental pollution
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent converts the harmful H2S and CO2 gases into beneficial dissolved forms in the water stream, which are then injected into geological reservoirs for mineralization, transforming the environmental hazard into a resource for carbon sequestration and sulfur recovery

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent extracts H2S and CO2 from the gas stream through absorption into the water stream, separating these harmful gases from the remaining gas mixture, and then removes them from the system through injection into geological formations

Inventive Principle:
Principle #2Taking out (Extraction)

3Loss of substance

If the entire non-condensable gas stream is mixed with water for disposal, then H2S and CO2 can be removed, but the process requires very large amounts of water due to varying solubility of different gases

Engineering Contradiction:
Improvegas disposal effectivenessVSAvoidwater requirement
Core Design Contradiction:
Loss of substanceVSQuantity of substance

Solution Approach 1:

The patent applies pressure changes (6-20 bar) to the gas stream before absorption, which fundamentally alters the solubility parameters and enables selective absorption of H2S and CO2 with much reduced water requirements compared to atmospheric pressure conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces an amine-based absorbent as an intermediary that enhances the selective absorption of H2S and CO2, allowing efficient gas removal with minimal water consumption by leveraging the chemical affinity of amines for these gases

Inventive Principle:
Principle #24Intermediary (Mediator)

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

Effectively separates and prepares H2S and CO2 for disposal or reuse by dissolving them in water, reducing emissions and utilizing natural water-rock reactions for abatement, while leaving other gases behind.

Implementation Method 1

contacting a stream of said pressurized gas mixture (G1), encompassing H2S and CO2 and at least also one of H2, N2, CH4 and/or Ar, with a stream of water (W2)... absorption of at least part of said H2S and CO2 from said pressurized gas mixture (G1)

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

injecting said water stream (W4) into a geological reservoir, where the dissolved CO2 and H2S are abated by mineralization by forming chemical bindings via water-rock reactions

Methodology Applied
Scientific EffectMineralization: Chemical Bonding

Data Source

PatentEP4031267B1A method for abating h2s and co2 from h2s and co2 rich gas mixtures such as geothermal non-condensable gas mixtures
Publication Date: 2026.03.25 EIGNARHALDSFÉLAGID CARBFIX OHF
  • EP4031267B1 patent drawingFigure 1~2
  • EP4031267B1 patent drawingFigure 3
  • EP4031267B1 patent drawingFigure 4

AI summary

This invention relates to a method and a system for abating hydrogen sulfide (H2S) and carbon dioxide (CO2) from H2S and CO2 rich gas mixtures such as geothermal non- condensable gas mixtures (NCG). The H2S and CO2 gas is separated from the remaining gases contained in the H2S and CO2 rich gas mixtures by pressurizing the gas stream and feeding it into an absorption column where H2S and CO2 are preferentially dissolved in a water stream, resulting in water stream rich in H2S and CO2. The H2S and CO2 rich water stream may then be re-injected into a geological reservoir or used for pH modification of another water stream of geological origin.