Ionic Liquid Alcohol Separation for Ether Production

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Solution Overview

Problem

Conventional methods for producing ethers from alcohols and olefins result in highly water-laden alcohol recycling, leading to catalyst deactivation and unwanted alcohol formation, due to the formation of azeotropes and inefficient separation processes, which are energy costly and accumulate impurities.

Innovation Solution

A method involving a non-aqueous ionic liquid with the formula Q+ A−, where Q+ is an ammonium, phosphonium, or sulfonium cation, is used to selectively absorb excess alcohol from the ether-hydrocarbon effluent, followed by regeneration and recycling, reducing water content and improving catalyst selectivity and activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional fractionating columns are used to separate alcohol from ether-hydrocarbon mixtures, then separation is achieved, but the alcohol becomes highly water-laden leading to catalyst deactivation and unwanted alcohol formation

Engineering Contradiction:

Improvealcohol purityVSAvoidwater content in alcohol

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a drying agent as an intermediary substance to mediate between the alcohol and water. The drying agent selectively absorbs water from the alcohol stream without reacting with the alcohol itself, thereby purifying the alcohol while avoiding catalyst deactivation and unwanted side reactions that occur with conventional water-laden alcohol recycling

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the physical-chemical parameters of the separation process by using a drying agent with specific hygroscopic properties. This alters the separation mechanism from conventional distillation-based methods to absorption-based water removal, achieving lower water content in the recycled alcohol stream

Inventive Principle:

Principle #35Parameter changes

2Productivity

If excess alcohol is used to shift the etherification equilibrium, then ether production increases, but separation complexity and energy consumption increase due to azeotrope formation

Engineering Contradiction:

Improveether productionVSAvoidseparation energy consumption

Core Design Contradiction:

ProductivityVSUse of energy by stationary object

Solution Approach 1:

The drying agent acts as an intermediary that selectively removes water from the alcohol stream without requiring energy-intensive distillation to break azeotropes. This intermediary approach allows excess alcohol to be used for equilibrium shifting while avoiding the high energy costs of conventional separation methods

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the separation approach from thermal distillation to chemical absorption using a drying agent. This parameter change in the separation mechanism reduces energy consumption while maintaining the ability to handle excess alcohol feeds for high ether production

Inventive Principle:

Principle #35Parameter changes

3Loss of substance

If water washing is used to remove alcohol from the ether cut, then alcohol recovery is attempted, but water-saturated ether is produced requiring additional treatment

Engineering Contradiction:

Improvealcohol recoveryVSAvoidwater saturation in ether

Core Design Contradiction:

Loss of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent uses a drying agent as an intermediary to remove water from the alcohol stream before recycling, rather than using water washing. This reverses the conventional approach and prevents water saturation in the ether product, eliminating the need for additional drying treatment of the ether stream

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

Instead of washing with water to remove alcohol (which saturates the ether with water), the patent inverts the approach by using a drying agent to remove water from the alcohol stream. This inversion prevents water contamination of the ether while still achieving alcohol recovery and recycling

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 approach allows for the recycling of alcohol with low water content and high purity, enhancing the selectivity and activity of the etherification reaction, reducing the alcohol content in the ether product to less than 0.5% by weight, compared to conventional methods which exceed 2.5% by weight, and improving overall process efficiency.

Implementation Method 1

contacting said effluent with a non-aqueous ionic liquid so that the ionic liquid becomes laden with alcohol and the effluent becomes depleted in alcohol

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 2

regenerating the alcohol-laden ionic liquid by separating said ionic liquid and the alcohol, said separation consisting in evaporating the alcohol, then in condensing it

Methodology Applied

Scientific EffectEvaporation: Evaporation

Data Source

PatentUS8748671B2Ether production method involving alcohol separation by an ionic liquid

Publication Date: 2014.06.10 IFP ENERGIES NOUVELLES

AI summary

An enhanced method of producing ethers from iso-olefins and alcohols comprises at least one stage of separation of the excess alcohol by an ionic liquid. The ether-hydrocarbon-alcohol effluent treated in said separation stage by the ionic liquid comes from the reaction section and/or from a fractionating column. The separated and condensed alcohol is recycled in the process.