Ship Propulsion System with Onboard Hydrogen Production

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Solution Overview

Problem

Current propulsion systems for ships face challenges due to high fuel consumption, environmental impact, and uncertainty related to the availability and cost of green fuels, with hydrogen technology being unsuitable for long transports due to low energy density and infrastructure limitations.

Innovation Solution

A propulsion system that uses onboard-produced hydrogen, integrated with LNG, through a methane steam reforming process, and combines it with hydrogen fuel cells or internal combustion engines, capturing and storing carbon dioxide for reduced emissions, and employing hybrid drive configurations for efficient energy conversion.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If hydrogen is used as fuel for ships, then environmental friendliness is improved, but energy density is insufficient and storage infrastructure is inadequate

Engineering Contradiction:
Improvegreenhouse gas emissionsVSAvoidenergy density
Core Design Contradiction:
Object-affected harmful factorsVSUse of energy by moving object

Solution Approach 1:

The patent segments the hydrogen supply chain into on-board production (via steam methane reforming) and off-board utilization (capturing CO2 for later use). This allows the ship to generate its own hydrogen from LNG while separating the CO2 emission problem from the propulsion function, resolving the contradiction between environmental friendliness and energy density by producing hydrogen on-demand rather than storing large quantities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces CO2 capture and storage as an intermediary process. By capturing and storing the CO2 produced during hydrogen generation, the system enables clean hydrogen use on-board while managing the environmental impact separately. This intermediary solution allows the ship to benefit from hydrogen's clean combustion without being constrained by hydrogen's low energy density, as the CO2 management is handled as a distinct function.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Object-affected harmful factors

If green fuels are produced and used, then environmental impact is reduced, but availability is insufficient and cost is too high

Engineering Contradiction:
Improveenvironmental impactVSAvoidfuel availability
Core Design Contradiction:
Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The patent implements self-service by enabling ships to produce their own hydrogen fuel on-board through steam methane reforming of LNG. This eliminates dependence on external green fuel supply chains, making fuel availability independent of current production limitations. The system uses the ship's existing LNG supply to generate hydrogen, ensuring fuel availability without requiring external green fuel infrastructure.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent changes the fuel parameter from direct LNG combustion to hydrogen produced from LNG via steam methane reforming. This parameter change allows the system to use readily available LNG infrastructure while producing cleaner hydrogen fuel on-demand, bridging the gap between current fuel availability and future green fuel requirements without being constrained by current green fuel production limits.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If conventional propulsion systems are used, then fuel availability is ensured, but fuel consumption is high and environmental impact is negative

Engineering Contradiction:
Improvefuel availabilityVSAvoidfuel consumption
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent substitutes the conventional thermal combustion mechanism with a two-stage process: steam methane reforming to produce hydrogen, followed by hydrogen combustion or fuel cell conversion. This mechanism substitution reduces fuel consumption by approximately 20% compared to direct LNG combustion while maintaining availability through the use of existing LNG infrastructure. The reforming process converts LNG to hydrogen more efficiently, and the subsequent hydrogen utilization provides cleaner, more efficient propulsion.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 system provides a sustainable, efficient, and environmentally friendly propulsion solution for ships, reducing greenhouse gas emissions and fuel consumption, while being suitable for transitional use and future compliance with environmental regulations.

Implementation Method 1

hot steam is mixed with the gas to be reformed, preferably natural gas or LNG, which contains methane as its main component, and reacted in the gas phase with the addition of energy at a catalyst. Ultimately, carbon dioxide and hydrogen are formed as reaction products

Methodology Applied
Scientific EffectSteam methane reforming: Chemical Transport Reactions

Implementation Method 2

the fuel hydrogen is converted with the atmospheric oxygen into water and electrical energy, i.e. bound chemical energy is converted into electrical energy with efficiencies of approx. 60%

Methodology Applied
Scientific EffectFuel cell electrochemical conversion: Fuel Cell

Implementation Method 3

This is done with compressors that compress carbon dioxide below the temperature of 31°C (critical temperature) by compression and cooling to a colorless liquid

Methodology Applied
Scientific EffectCompression and cooling liquefaction: Compression

Implementation Method 4

CO2 can also be separated by the well-known process of cryogenic separation at very low temperatures

Methodology Applied
Scientific EffectCryogenic separation: Cryogenics

Data Source

PatentEP4230574A1Propulsion system for a ship
Publication Date: 2023.08.23 RINA HELLAS LTD

AI summary

The invention relates to a propulsion system for a ship comprising at least one combustion unit for a methane-containing fuel, at least one methane steam reformer, at least one hydrogen fuel cell and/or at least one combustion engine running on hydrogen, at least one device for separating formed carbon dioxide and at least one transmission unit for driving the ship's propeller.