Guerbet Reaction Yield via Hydrogen Gas Flow

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Solution Overview

Problem

The Guerbet reaction yields decrease when using branched alcohols as starting materials due to steric hindrance, leading to lower production efficiency and increased costs in industrial processes.

Innovation Solution

Conducting the Guerbet reaction under atmospheric pressure while blowing in hydrogen gas, using a base and catalyst, and removing water formed during the reaction to improve yield, particularly effective with branched aliphatic monoalcohols like 3,5,5-trimethyl-1-hexanol.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a branched alcohol is used as the starting material for the Guerbet reaction, then the reaction proceeds slower due to steric hindrance, but the yield of the target compound decreases

Engineering Contradiction:
Improvereaction rateVSAvoidyield of target compound
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The invention changes the physical-chemical parameters of the reaction system by introducing hydrogen gas and using a specific catalyst system (metal oxide or aldehyde) with a base. This combination creates new reaction pathways that overcome the steric hindrance of branched alcohols, allowing both high reaction rate and high yield to be achieved simultaneously through parameter optimization rather than traditional conditions

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention introduces hydrogen gas as an intermediary substance that mediates the reaction between branched alcohol and catalyst. The hydrogen facilitates the hydrogen transfer reaction mechanism, enabling the reaction to proceed efficiently despite the steric hindrance of the branched structure, thus resolving the contradiction between reaction rate and yield

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of manufacture

If conventional Guerbet reaction conditions are used with branched alcohols, then the reaction can proceed, but the yield is low leading to increased production costs

Engineering Contradiction:
Improveproduction costVSAvoidyield of dimerized alcohol
Core Design Contradiction:
Ease of manufactureVSQuantity of substance

Solution Approach 1:

The invention optimizes reaction parameters including using atmospheric pressure instead of high pressure, introducing hydrogen gas flow, and selecting specific catalyst-base combinations. These parameter changes collectively improve the yield to 90% or higher, which directly reduces production costs by minimizing waste and maximizing product output from the same amount of starting material

Inventive Principle:
Principle #35Parameter changes

3Ease of operation

If hydrogen pressurization is used in an autoclave as disclosed in prior art, then the reaction can proceed under pressure, but the system becomes more complex and less suitable for open system operation

Engineering Contradiction:
Improvesystem simplicityVSAvoidyield improvement
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

Instead of using high pressure in a closed autoclave system as in conventional methods, the invention inverts the approach by using atmospheric pressure with continuous hydrogen gas flow in an open system. This inversion achieves the same yield improvement (90% or higher) while dramatically simplifying the system complexity and making it more suitable for industrial open system operation

Inventive Principle:
Principle #13The other way round (Inversion)

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 yield of dimerized alcohol production, reduces by-product acid formation, and simplifies distillation and purification processes, making it suitable for large-scale industrial production.

Implementation Method 1

a mechanism in which hydrogen is added to the α,β-unsaturated aldehyde intermediate (Hydrogen transfer reaction) to form an alcohol

Methodology Applied
Scientific EffectHydrogen transfer reaction: Redox Reactions

Implementation Method 2

the abstraction of hydrogen from a starting alcohol in the presence of a basic compound and a catalyst (hydrogen transfer reaction) to form the corresponding aldehyde intermediate

Methodology Applied
Scientific EffectDehydrogenation: Redox Reactions

Implementation Method 3

a mechanism in which the aldehyde intermediate is dimerized via aldol condensation to form an α,β-unsaturated aldehyde intermediate

Methodology Applied
Scientific EffectAldol condensation: Chemical Bonding

Data Source

PatentUS10179755B2Method for preparing branched alcohol
Publication Date: 2019.01.15 NISSAN CHEM CORP

AI summary

A method for preparing a branched alcohol by dimerizing an aliphatic monoalcohol having three or more carbon atoms in the presence of a base and a catalyst. The dimerization reaction is performed under atmospheric pressure while injecting a hydrogen gas. With this method, it is possible to obtain a dimerized alcohol with excellent yield even when using a branched aliphatic monoalcohol as the starting material.