Carbon-Neutral Methane Grid Management for Calorific Value Control

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Solution Overview

Problem

The introduction of carbon neutral methane (CN-CH4) into existing gas grids faces challenges due to variations in calorific value, requiring both digital-based transactions and physical management of the grid to maintain gas quality, unlike electric power trading which only requires digital transactions.

Innovation Solution

A carbon neutral methane management system that includes an arithmetic processing unit to calculate calorific values, a supply/use management unit to adjust gas amounts, and a certificate issuing unit to ensure compliance with grid restrictions and issue certificates for CN-CH4 supply and use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If carbon neutral methane is introduced into the existing gas grid, then carbon neutral gas distribution goal is advanced, but gas quality (calorific value) becomes variable and difficult to control

Engineering Contradiction:
Improvecarbon neutral gas distribution progressVSAvoidgas quality (calorific value)
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The system dynamically adjusts the proportion of city gas and carbon neutral methane based on their respective calorific values to maintain the mixed gas within the required calorific value range. The control unit calculates appropriate mixing ratios by comparing the calorific values of individual gas components and adjusts supply quantities accordingly, transforming a quality control problem into a parameter optimization problem.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The system implements feedback control by continuously monitoring the actual calorific value of the mixed gas and comparing it with the target range. Based on this feedback, the control unit adjusts the supply quantities of city gas and carbon neutral methane in real-time, ensuring stable gas quality despite variations in carbon neutral methane introduction.

Inventive Principle:
Principle #23Feedback

2Adaptability or versatility

If carbon neutral methane is supplied to the grid, then environmental value trading is enabled, but physical grid management complexity increases

Engineering Contradiction:
Improveenvironmental value trading capabilityVSAvoidphysical grid management
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system merges digital certificate management with physical gas supply control into an integrated management framework. The control unit coordinates both the physical mixing of gases and the digital issuance of carbon neutral certificates, ensuring that environmental value trading reflects actual physical gas composition and supply conditions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The control unit acts as an intermediary between carbon neutral methane suppliers, city gas suppliers, and certificate issuing authorities. It receives supply information from various sources, calculates calorific values, determines appropriate mixing ratios, and coordinates the entire process to enable environmental value trading while managing physical grid operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If mixed gas with varying calorific value is distributed, then carbon neutral methane utilization increases, but fair trading between suppliers and consumers becomes difficult

Engineering Contradiction:
Improvecarbon neutral methane utilizationVSAvoidtrading fairness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The system uses feedback from actual gas supply and consumption data to calculate accurate calorific values of mixed gas. This feedback mechanism ensures that trading terms reflect real-world conditions, providing transparency and fairness in transactions between carbon neutral methane suppliers, city gas suppliers, and consumers.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The control unit performs preliminary calculations of calorific values and determines trading conditions before gas supply and consumption occur. By pre-calculating the expected calorific value based on planned supply quantities and compositions, the system establishes fair trading terms in advance, avoiding disputes and ensuring transparency in the trading process.

Inventive Principle:
Principle #10Preliminary action

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 system effectively manages gas composition changes in the grid, ensuring fair trading and maintaining calorific value within specified ranges, thereby enabling the issuance of CN certificates.

Implementation Method 1

an arithmetic processing unit that calculates a calorific value of the mixed gas in the grid

Methodology Applied
Scientific EffectCalorific value calculation:

Implementation Method 2

a supply/use management unit that gives an instruction to adjust at least an amount of the city gas supplied to the grid or an amount of the city gas used by the user or an amount of the carbon neutral methane supplied to the grid or an amount of the carbon neutral methane used by the user

Methodology Applied
Scientific EffectGas flow control:

Implementation Method 3

Synthetic methane is created by a reaction expressed by the following chemical formula (1). CO2 + 4H2 → CH4 + 2H2O

Methodology Applied
Scientific EffectChemical reaction: Chemical Bonding

Implementation Method 4

biomethane produced by fermentation treatment of organic wastes, such as food waste and livestock manure

Methodology Applied
Scientific EffectFermentation: Fermentation

Data Source

PatentEP4621697A1Carbon neutral methane management system
Publication Date: 2025.09.24 HITACHI LTD
  • EP4621697A1 patent drawingFigure 1
  • EP4621697A1 patent drawingFigure 2
  • EP4621697A1 patent drawingFigure 3A~3B

AI summary

A carbon neutral methane management system (1) is used for a grid that supplies a user with a mixed gas including city gas and carbon neutral methane (hereinafter, "CN-CH4"). The carbon neutral methane management system (1) includes: an arithmetic processing unit (13) that calculates a calorific value of the mixed gas in the grid; a supply/use management unit (12) that gives an instruction to adjust at least an amount of the city gas supplied to the grid or an amount of city gas used by the user or an amount of CN-CH4 supplied to the grid or an amount of CN-CH4 used by the user so that the calorific value of the mixed gas is kept within a restriction range of the grid; and a certificate issuing unit (11) that issues a certificate certifying that an amount of CN-CH4 supplied to the grid by a CN-CH4 supplier matches an amount of CN-CH4 supplied that has been adjusted by the supply/use management unit or a certificate certifying that an amount of CN-CH4 used by the user matches an amount of CN-CH4 used that has been adjusted by the supply/use management unit.