Floating Gas Collection Membrane for Methane Hydrate Recovery

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Solution Overview

Problem

Existing methods for collecting gases like methane from sea bottoms often interfere with fishery resources and are inefficient due to the need for stable anchoring and mixing with seawater, which affects gas collection efficiency.

Innovation Solution

A gas collecting method using a collecting membrane that is positioned with its lower end higher than the sea bottom and shallower than the water depth where methane hydrate separates into water and gas, allowing for efficient gas collection without affecting fishery resources, utilizing weights or autonomous underwater robots to maintain the membrane's position and collect methane gas before it mixes with seawater.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If anchors are disposed on the sea bottom to fix the dome-shaped frame body stably, then the frame body can be fixed stably for crude collection, but fishery resources on the sea bottom such as shrimps and crabs are affected

Engineering Contradiction:
Improvestability of frame bodyVSAvoidimpact on fishery resources
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the anchoring function from the collection system by using a drifting collection membrane that does not require anchors on the sea bottom. The membrane is kept afloat by buoyancy forces and collects gas bubbles rising from the sea bottom without fixing the collection device to the bottom, thereby avoiding harm to fishery resources while maintaining collection stability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces an intermediary floating membrane structure between the sea bottom and the collection point. This membrane acts as a mediator that captures rising gas bubbles without requiring direct contact with or fixation to the sea bottom, thus preventing damage to benthic ecosystems while maintaining effective gas collection

Inventive Principle:
Principle #24Intermediary (Mediator)

2Productivity

If the collecting membrane lower end is positioned close to the sea bottom for efficient gas collection, then gas collection efficiency improves, but fishery resources on the sea bottom are affected

Engineering Contradiction:
Improvegas collection efficiencyVSAvoidimpact on fishery resources
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The invention applies local quality by positioning the collecting membrane at a specific water depth that is optimized for gas collection while avoiding the sea bottom. The membrane is placed in the water column where gas bubbles naturally rise, collecting methane efficiently without needing to contact or anchor to the sea bottom, thus protecting benthic fishery resources

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention transitions from a two-dimensional sea bottom anchoring system to a three-dimensional water column floating membrane system. By collecting gas bubbles in the water column rather than anchoring to the bottom, the system achieves efficient gas collection while creating vertical separation from benthic ecosystems, thereby protecting fishery resources

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Quantity of substance

If gas is collected from deep water where methane hydrate separates into water and gas, then gas collection is possible, but gas mixes with seawater reducing collection efficiency

Engineering Contradiction:
Improveamount of gas collectedVSAvoidcollection efficiency
Core Design Contradiction:
Quantity of substanceVSProductivity

Solution Approach 1:

The invention performs preliminary action by positioning the collecting membrane at the optimal water depth where methane hydrate begins to separate into water and gas. By placing the membrane in this separation zone rather than deeper waters, the system captures gas bubbles at the source before they can mix extensively with seawater, maintaining high collection efficiency while maximizing gas quantity

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

This method enables efficient collection of methane gas from methane hydrate without harming fishery resources and allows for easy movement and deployment, avoiding the need for stable anchoring and minimizing gas mixing with seawater, thus improving collection efficiency and reducing environmental impact.

Implementation Method 1

Gas hydrate sediment under a sea bottom separates into water and gas according to conditions such as a temperature and a pressure, and then the separated gas floats up toward a sea surface

Methodology Applied
Scientific EffectGas-liquid separation:

Implementation Method 2

the separated gas floats up toward a sea surface

Methodology Applied
Scientific EffectBuoyancy: Archimedes' Principle (Buoyancy)

Data Source

PatentEP3428384B1Gas collection method
Publication Date: 2023.06.14 KUBUSHIKI KAISHA AOYAMA
  • EP3428384B1 patent drawingFigure 1
  • EP3428384B1 patent drawingFigure 2~3
  • EP3428384B1 patent drawingFigure 4

AI summary

In a gas collecting method for collecting gas yielding from source material (PL) that exists on a sea bottom (L1) or a lake bottom, [1] releasing a collecting membrane (11) into water, a fixture being connected with a lower end of the collecting membrane (11) and the collecting membrane (11) being configured of a membrane that flares downward from its top; [2] by a position maintainer (31) provided in the fixture (31), recognizing a three-dimensional position of the fixture in the water and then keeping the three-dimensional position of the fixture (31) at a target position by its autonomous navigation; [3] based on vertical water temperature distribution obtained by an CTD, setting the lower end of the collecting membrane (11) at a position that is higher than the sea bottom (L1) or the lake bottom and shallower than a water depth where the source material (PL) separates from its solid state into water and gas and setting the top (T1) of the collecting membrane (11) at a deeper position than a water depth where bubbles of the gas disappear due to mixture of the gas with seawater or lakewater; and [4] collecting the gas released from the sea bottom (L1) or the lake bottom by the collecting membrane (11).