Underground Methanogenesis for Hydrogen and CO2 Storage

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Solution Overview

Problem

Current methods for storing hydrogen and CO2 face challenges such as high storage losses, instability, and competition with other energy uses, particularly in underground storage facilities, where hydrogen can be explosive and CO2 storage can cause geological instability and induced earthquakes.

Innovation Solution

A method involving a gas mixture of hydrogen, carbon dioxide, and natural gas with a minimum 10% natural gas concentration, introduced into an underground storage facility in the presence of methanogenic microorganisms, where hydrogen is produced using renewable energy and CO2 is separated, allowing for efficient conversion to methane, thereby stabilizing the storage environment and promoting continuous conversion without substrate inhibition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If hydrogen and CO2 are stored separately in underground facilities, then storage capacity is maximized, but storage losses increase and geological stability deteriorates

Engineering Contradiction:
Improvestorage capacityVSAvoidstorage losses
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent combines hydrogen and CO2 storage into a single underground facility, allowing simultaneous injection and conversion. The hydrogen and CO2 are mixed in a porous reservoir where methanogenic microorganisms convert them to methane in-situ, eliminating the need for separate storage facilities and reducing storage losses through continuous conversion.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent converts the potentially harmful combination of hydrogen and CO2 (which could cause geological instability) into a beneficial process by introducing methanogenic microorganisms. These microorganisms consume the hydrogen and CO2 to produce methane, transforming a risky storage scenario into a productive energy storage and conversion system.

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

2Quantity of substance

If hydrogen concentration is increased to improve energy density, then storage efficiency improves, but explosion risk increases

Engineering Contradiction:
Improveenergy densityVSAvoidexplosion risk
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent addresses the explosion risk of high-concentration hydrogen by introducing methanogenic microorganisms that continuously consume hydrogen and CO2 to produce methane. This converts the explosive hydrogen gas into stable methane in-situ, allowing high energy density storage while eliminating the explosion hazard through biological conversion.

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

Solution Approach 2:

The methanogenic microorganisms act as an intermediary between hydrogen and methane, providing a safe conversion pathway. Instead of directly storing high-concentration hydrogen (which is explosive), the system uses microorganisms as a mediator to gradually convert hydrogen to methane, maintaining safety while achieving energy storage goals.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Quantity of substance

If CO2 is stored in underground aquifers to maximize storage capacity, then storage volume increases, but geological stability decreases and induced earthquakes occur

Engineering Contradiction:
Improvestorage volumeVSAvoidgeological stability
Core Design Contradiction:
Quantity of substanceVSStability of the object's composition

Solution Approach 1:

The patent converts the harmful effect of CO2 injection (geological instability and induced earthquakes) into a beneficial process by simultaneously injecting hydrogen and introducing methanogenic microorganisms. The microorganisms consume CO2 to produce methane, reducing the pressure buildup and geological stress associated with pure CO2 storage while maintaining storage volume.

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

Solution Approach 2:

The patent merges CO2 storage with hydrogen conversion into a single process. Instead of storing CO2 alone (which causes geological instability), the system combines CO2 with hydrogen and microorganisms to create an in-situ methane production system, achieving storage volume while improving geological stability through chemical conversion.

Inventive Principle:
Principle #5Merging (Combining)

4Productivity

If methanogenic microorganisms are used to convert CO2 and H2 to CH4, then productivity increases, but substrate inhibition occurs at high natural gas concentrations

Engineering Contradiction:
Improvemethane production rateVSAvoidconversion stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent optimizes the concentration parameters of the gas mixture to overcome substrate inhibition. By controlling the ratios of hydrogen, CO2, and natural gas within specific ranges, the system maintains high methane production rates while avoiding the inhibitory effects that occur at extreme concentrations, ensuring stable and reliable conversion.

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

This method enhances the productivity of methanogenic microorganisms, achieving continuous conversion of CO2 and H2 to CH4 with reduced gas losses and geological stability, allowing for efficient storage and utilization of renewable energy by equalizing fluctuating energy sources.

Implementation Method 1

a method for hydrogenotrophic methanogenesis of H2 and CO2 to CH4

Methodology Applied
Scientific EffectHydrogenotrophic methanogenesis: Anaerobic Digestion

Data Source

PatentEP3280807B1Method for hydrogenotrophic methanogenesis of h2 and co2 to ch4
Publication Date: 2019.10.09 RAG AUSTRIA AG
  • EP3280807B1 patent drawingFigure 1
  • EP3280807B1 patent drawingFigure 2
  • EP3280807B1 patent drawingFigure 3

AI summary

The invention relates to a method for the hydrogenotrophic methanogenesis of H2 and CO2 into CH4, characterized in that a gas mixture comprising natural gas, hydrogen, and CO2 and having a minimum concentration of natural gas of 10% and preferably a ratio between hydrogen and CO2 that is stoichiometric for the formation of CH4 is introduced into an underground store comprising a gas zone and is stored there in the presence of methanogenic microorganisms. The invention further relates to the use of such a method to control the content of CO2 and/or hydrogen in a natural gas.