Ethene Oligomerization via MTHxE Etherification and Cleavage

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Solution Overview

Problem

The separation of valuable olefins like 1-hexene and octene from complex mixtures produced by ethene oligomerization is economically challenging due to close boiling points of isomers, leading to inefficient distillation processes and waste of carbon atoms as fuel.

Innovation Solution

A process involving catalytic cleavage of methyl tert-hexyl ether (MTHxE) back into C6 olefins and alcohol, recycling the alcohol for etherification, and reacting C6 olefins with ethene to form octenes, thereby upgrading less attractive olefins and conserving carbon atoms for chemical use.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If distillation is used to separate olefins with the same number of carbon atoms, then separation can be achieved, but equipment complexity and energy consumption increase significantly

Engineering Contradiction:
Improveseparation purityVSAvoiddistillation equipment
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent uses an etherification reaction as an intermediary step to convert C6 olefins into ethers with significantly different boiling points. This intermediary chemical transformation enables easy distillation separation without requiring complex distillation equipment, as the ether products have much higher boiling points than the original olefins.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If distillation is used to separate olefins with the same number of carbon atoms, then separation can be achieved, but energy consumption increases significantly

Engineering Contradiction:
Improveseparation purityVSAvoiddistillation energy
Core Design Contradiction:
Manufacturing precisionVSUse of energy by stationary object

Solution Approach 1:

The patent changes the chemical parameters of the olefins by converting them into ethers through etherification. This parameter change (from olefin to ether) results in a dramatic change in boiling point, allowing separation to occur at much lower energy costs in subsequent distillation steps.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If C6 olefins are separated from oligomerization mixture, then 1-hexene can be obtained, but carbon atoms are wasted as fuel

Engineering Contradiction:
Improve1-hexene purityVSAvoidcarbon atoms
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

The patent converts the harmful waste (C6 olefins that would be burned as fuel) into a beneficial product (ethers). By etherifying the C6 olefins, the process transforms what would be waste material into valuable ether products, thereby eliminating carbon atom loss and creating additional revenue streams.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Ease of operation

If etherification is performed to separate C6 olefins, then separation becomes easier, but additional process steps are required

Engineering Contradiction:
Improveseparation easeVSAvoidprocess steps
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the separation function with the etherification reaction itself. The etherification step simultaneously performs chemical transformation and creates a basis for easy separation, combining what would otherwise be separate operations into an integrated process flow.

Inventive Principle:
Principle #5Merging (Combining)

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 process efficiently recovers 1-hexene and octene with minimal additional effort, enhancing the utilization of carbon atoms and producing additional sales products, thus improving the economic viability of ethene-based olefin production.

Implementation Method 1

a solid containing at least two components is used as a heterogeneous catalyst in the first oligomerization and/or in the second oligomerization

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

Subjecting the C6 fraction to etherification upon addition of an alcohol in the presence of a heterogeneous catalyst to obtain a first reaction mixture containing at least 1-hexene and 3-methyl-3-methoxypentane

Methodology Applied
Scientific EffectEtherification: Chemical Bonding

Implementation Method 3

the ether fraction is subjected to a cleavage reaction, yielding a cleavage product containing 3-methyl-cis-2-pentene, 3-methyl-trans-2-pentene, and the alcohol

Methodology Applied
Scientific EffectCleavage reaction: Decomposition (biological)

Implementation Method 4

Working up the first oligomer by distillation, obtaining a C6 fraction containing at least 1-hexene, 3-methyl-cis-2-pentene, and 3-methyl-trans-2-pentene

Methodology Applied
Scientific EffectDistillation: Distillation

Data Source

PatentEP3266757B1Producing at least 1-hexene and octen from ethene
Publication Date: 2019.12.25 EVONIK OPERATIONS GMBH
  • EP3266757B1 patent drawingFigure 1
  • EP3266757B1 patent drawingFigure 2
  • EP3266757B1 patent drawingFigure 3

AI summary

The invention relates to the production of 1-hexene and octenes from ethene. Optionally, 1-butene can also be produced. The underlying objective is to further develop a process for the production of 1-hexene from ethene via MTHxE etherification in such a way that the carbon atoms used are chemically utilized more effectively. This objective is achieved by catalytically cleaving MTHxE back into the C6 olefins and the alcohol, recycling the alcohol during the etherification, and reacting the resulting C6 olefins with ethene to form C8 olefins. In this way, the alcohol from the process is not lost but is recycled internally as a derivatizing agent. The less desirable C6 olefins from the cleavage product are upgraded to octene with further ethene, thus providing an additional marketable product.