Partial Dehydrogenation of Organic Liquids for Hydrogen Storage

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Solution Overview

Problem

Current hydrogen transport and storage technologies using liquid organic hydrogen carriers, such as dibenzyltoluene, face significant degradation during hydrogenation/dehydrogenation cycles, leading to reduced performance and hydrogen purity, requiring severe operating conditions and frequent replacement of carrier liquids, which is economically and operationally inefficient for large-scale hydrogen use.

Innovation Solution

Implementing a process of partial dehydrogenation of organic liquids with a Degree of Hydrogenation ratio between 1 and 25, controlling dehydrogenation conditions to avoid 100% yield, using lower temperatures and pressures, and selecting appropriate catalysts to reduce energy expenditure and thermal degradation, thereby enhancing the stability and longevity of the carrier liquid.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If total dehydrogenation is performed to release maximum hydrogen, then hydrogen yield is improved, but carrier liquid degradation increases and operational lifetime decreases

Engineering Contradiction:
Improvehydrogen yieldVSAvoidcarrier liquid stability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies partial dehydrogenation instead of complete dehydrogenation. The process stops at the H2-DBT stage (partial dehydrogenation) rather than proceeding to full dehydrogenation, thereby releasing only a portion of the stored hydrogen. This partial action reduces thermal stress and chemical degradation on the carrier liquid, extending its operational lifetime while still achieving useful hydrogen yield.

Inventive Principle:
Principle #16Partial or excessive action

2Productivity

If severe operating conditions (280-300°C) are used for total dehydrogenation, then hydrogen release efficiency is improved, but carrier liquid degradation accelerates and performance decreases

Engineering Contradiction:
Improvehydrogen release efficiencyVSAvoidcarrier liquid composition stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

The patent changes the dehydrogenation parameters by lowering the temperature range and extending the reaction time. Instead of using 280-300°C for complete dehydrogenation, the process uses milder conditions (lower temperature) for partial dehydrogenation to the H2-DBT stage. This parameter change reduces thermal degradation while maintaining acceptable hydrogen release efficiency.

Inventive Principle:
Principle #35Parameter changes

3Quantity of substance

If complete hydrogenation to perhydrodibenzyltoluene is performed, then hydrogen storage capacity is improved, but subsequent dehydrogenation requires severe conditions causing degradation

Engineering Contradiction:
Improvehydrogen storage capacityVSAvoidthermal degradation during dehydrogenation
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The patent segments the dehydrogenation process into stages, stopping at the H2-DBT intermediate stage rather than proceeding to complete dehydrogenation. This segmentation allows the system to release a useful amount of hydrogen (from perhydrodibenzyltoluene to H2-DBT) while avoiding the severe conditions required for the final dehydrogenation steps, thereby reducing thermal degradation and improving carrier liquid stability.

Inventive Principle:
Principle #1Segmentation

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 approach significantly reduces the degradation of organic liquids, increases the number of hydrogenation/dehydrogenation cycles, and maintains high hydrogen purity, making the technology more economically viable for large-scale hydrogen transport and use.

Implementation Method 1

a step of partially dehydrogenating said liquid

Methodology Applied
Scientific EffectDehydrogenation: Chemical Bonding

Implementation Method 2

using lower temperatures and pressures, and selecting appropriate catalysts to reduce energy expenditure

Methodology Applied
Scientific EffectCatalysis: Catalysis

Data Source

PatentUS20230137373A1Partial dehydrogenation of organic liquids
Publication Date: 2023.05.04 EASTMAN CHEMICAL HTF GMBH

AI summary

The present invention concerns a process for producing hydrogen by partial dehydrogenation of an organic liquid, said process comprising a step of supplying at least one organic liquid having a Degree of Hydrogenation DHplus, a step of partially dehydrogenating said liquid, a step of recovering firstly gaseous hydrogen and secondly said organic liquid having a Degree of Hydrogenation DHminus, and wherein the ratio DHplus/DHminus is between 1 and 25, endpoints excluded.The invention likewise concerns a hydrogenation/dehydrogenation cycle comprising at least the process of the invention for producing hydrogen by partial dehydrogenation of an organic liquid and at least one hydrogenation reaction of said organic liquid.