Ethylene Dimerization Effluent Neutralization

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Solution Overview

Problem

The dimerization of ethylene into but-1-ene using homogeneous catalysts based on transition metals faces challenges with secondary reactions and catalyst residue contamination, leading to reduced selectivity and purity of the desired product, and existing neutralization methods using amines are toxic and environmentally problematic.

Innovation Solution

A method involving the neutralization of the raw effluent from ethylene dimerization using an alcohol of general formula R1OH, where R1 is an alkyl or aryl group with 6-20 carbon atoms, to reduce secondary reactions and prevent catalyst residue contamination during purification.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If homogeneous catalysts based on transition metals are used for ethylene dimerization, then the dimerization reaction can be carried out, but secondary reactions occur that reduce the selectivity of but-1-ene

Engineering Contradiction:
Improvedimerization reaction efficiencyVSAvoidselectivity of but-1-ene
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

A homogeneous catalyst system comprising a transition metal complex (such as titanium, nickel, or palladium complex) and an aluminum-based activator is used as an intermediary to facilitate the dimerization reaction. The catalyst system mediates between ethylene molecules, enabling controlled coupling while minimizing unwanted secondary reactions through selective catalytic activity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent optimizes reaction parameters including temperature (20-100°C), pressure (1-10 MPa), and catalyst concentration to control the reaction pathway. By carefully adjusting these parameters, the reaction selectively produces but-1-ene while suppressing isomerization and other secondary reactions that would reduce selectivity.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If amine-based neutralization is used to treat catalyst residue, then the catalyst can be neutralized, but toxicity and environmental problems arise

Engineering Contradiction:
Improvecatalyst neutralization effectivenessVSAvoidtoxicity of neutralization agent
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent employs water as a neutralization agent instead of toxic amines. Water is inexpensive, non-toxic, and effectively neutralizes the aluminum-based activator residue by forming aluminum hydroxide precipitate, which can be easily separated. This disposable, environmentally friendly approach eliminates the harmful effects associated with amine-based neutralization.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If the reaction effluent is not neutralized, then the process is simple, but the catalyst residue alters the purity of the reaction product

Engineering Contradiction:
Improveprocess simplicityVSAvoidpurity of but-1-ene
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The patent performs neutralization of the catalyst residue immediately after the dimerization reaction by adding water to the reaction effluent. This preliminary action occurs before any purification or separation steps, ensuring that the catalyst is deactivated and cannot cause further unwanted reactions or contamination, thereby preserving the purity of the but-1-ene product.

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 enhances the yield and selectivity of but-1-ene by minimizing isomerization and uncontrolled reactions, while being economically viable and environmentally friendly by eliminating the toxicity issues associated with amine-based neutralization.

Implementation Method 1

a method for treatment of the raw effluent that is obtained directly from a step for dimerization of ethylene into but-1-ene, comprising a step for neutralization of the catalytic system of the raw effluent by using an alcohol of general formula R1OH

Methodology Applied
Scientific EffectNeutralization reaction: Chemical Bonding

Data Source

PatentUS10544069B2Method for dimerization of ethylene comprising a step for treatment of the reaction effluent
Publication Date: 2020.01.28 IFP ENERGIES NOUVELLES

AI summary

The invention describes a method for dimerization of ethylene implementing a step for treatment of raw effluent by neutralization, at the outlet of the reactor, of the catalyst for dimerization of ethylene into but-1-ene by a particular alcohol.