Allyl Alcohol Production Distillation for Catalyst Protection

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Solution Overview

Problem

Current processes for producing allyl alcohol are inefficient in removing heavy impurities like allyl diacetate, which can deactivate solid acid catalysts used in subsequent hydrolysis steps, requiring additional steps for decomposition.

Innovation Solution

A process involving the reaction of propylene, acetic acid, and oxygen in the presence of a supported palladium catalyst, followed by distillation to separate streams, including a side draw for hydrolysis to allyl alcohol, where allyl diacetate is efficiently removed using an acetic acid vaporizer instead of a decomposition reactor.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the liquid stream is directly hydrolyzed without removing allyl diacetate, then the hydrolysis process can proceed, but the solid acid catalyst will be deactivated by heavy impurities like allyl diacetate

Engineering Contradiction:
Improvehydrolysis process continuityVSAvoidcatalyst activity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies preliminary action by removing allyl diacetate through distillation before the hydrolysis step. The liquid stream undergoes distillation to separate and remove heavy impurities like allyl diacetate in the bottoms stream, ensuring that only purified allyl acetate proceeds to hydrolysis. This preliminary removal prevents catalyst deactivation and maintains continuous hydrolysis operation.

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If a decomposition reactor is used to remove allyl diacetate, then heavy impurities can be eliminated, but the process complexity and equipment requirements increase

Engineering Contradiction:
Improveimpurity removal efficiencyVSAvoidprocess equipment
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies universality by using a distillation column that performs multiple functions: it separates propylene from the liquid stream, removes heavy impurities like allyl diacetate, and prepares the purified allyl acetate for hydrolysis. This single distillation unit replaces what would otherwise require separate decomposition reactors and additional processing equipment, simplifying the overall process while maintaining high impurity removal efficiency.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Device complexity

If allyl diacetate is not removed from the liquid stream, then the process steps are minimized, but the solid acid catalyst used in hydrolysis will be deactivated

Engineering Contradiction:
Improvenumber of process stepsVSAvoidcatalyst performance
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent applies preliminary action by implementing distillation as a pre-treatment step before hydrolysis. The distillation column removes allyl diacetate and other heavy impurities from the liquid stream, producing a purified feed for the hydrolysis reactor. This preliminary purification ensures catalyst performance is maintained throughout the hydrolysis process, avoiding deactivation issues that would arise from direct hydrolysis of the unprocessed liquid stream.

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 effectively separates heavy impurities like allyl diacetate without the need for decomposition reactors, enhancing the economic efficiency of allyl alcohol production by directly integrating impurity removal into the distillation process.

Implementation Method 1

reacting propylene, acetic acid, and oxygen in the presence of a supported palladium catalyst to produce a reaction mixture comprising allyl acetate, acetic acid, acrolein, and allyl diacetate

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

The reaction mixture is distilled to produce a vapor stream comprising propylene and a liquid stream comprising allyl acetate, acetic acid, acrolein, and allyl diacetate

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 3

The bottoms stream is distilled to remove a heavies stream comprising allyl diacetate

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 4

The side draw is hydrolyzed to produce allyl alcohol

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentEP2539306B1Process for producing allyl alcohol
Publication Date: 2015.04.29 LYONDELL CHEMICAL TECHNOLOGY LP
  • EP2539306B1 patent drawingFigure 1

AI summary

A process for producing allyl alcohol is disclosed. The process comprises reacting propylene, acetic acid, and oxygen to produce a reaction mixture. The reaction mixture is distilled to produce a vapor stream comprising propylene and a liquid stream comprising allyl acetate, acetic acid, acrolein, and allyl diacetate. The liquid stream is distilled to produce a lights stream comprising acrolein; a side draw comprising allyl acetate, acetic acid, and water; and a bottoms stream comprising acetic acid and allyl diacetate. The bottoms stream is distilled to remove a heavies stream comprising allyl diacetate. The side draw is hydrolyzed to produce allyl alcohol.