Isophorone Production via Two-Stage Catalytic Aldol Condensation

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Solution Overview

Problem

The production of isophorone is hindered by low selectivity and high yields of undesirable by-products due to a complex reaction network, with existing methods requiring limited acetone conversion and being prone to catalyst deactivation by carbonization residues, and there is a need to improve the economic and ecological aspects of the process.

Innovation Solution

A process involving catalyzed aldol condensations with acetone using a homogeneous catalyst, followed by hydrolysis and separation into organic and aqueous fractions, where isophorone is recovered from the organic fraction and the aqueous fraction is subjected to distillative work-up with vapors recycled to the hydrolysis apparatus, optimizing reaction conditions in a liquid-phase or gas-phase reaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If limited acetone conversion is used to minimize by-products, then selectivity to isophorone is improved, but productivity is worsened

Engineering Contradiction:
Improveselectivity to isophoroneVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The reaction process is divided into two distinct stages: a first reaction stage operating at lower conversion (10-30%) to maximize isophorone selectivity, and a second reaction stage operating at higher conversion (30-70%) to maximize productivity. This segmentation allows each stage to be optimized for its specific function without compromise

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first reaction stage performs preliminary conversion of acetone to isophorone under optimized conditions before proceeding to the second stage. This preliminary action ensures high selectivity is achieved early, setting the foundation for subsequent productivity enhancement

Inventive Principle:
Principle #10Preliminary action

2Manufacturing precision

If homogeneous catalysts are used to achieve high selectivity, then manufacturing precision is improved, but reliability is worsened due to catalyst deactivation

Engineering Contradiction:
Improveselectivity to isophoroneVSAvoidcatalyst stability
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The catalytic process is segmented into two stages with different catalyst systems: the first stage uses a homogeneous base catalyst (NaOH, KOH, or CsOH) optimized for high selectivity, while the second stage uses a heterogeneous catalyst (alumina, silica, or zeolite) that is resistant to deactivation. This segmentation allows each catalyst to operate in its optimal performance window

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention changes the catalyst type parameter between stages and adjusts operating conditions (temperature, pressure, residence time) to match each catalyst's characteristics. The first stage operates at milder conditions with homogeneous catalyst for selectivity, while the second stage uses more robust conditions with heterogeneous catalyst for stability

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If complex separation and purification processes are used to remove by-products, then manufacturing precision is improved, but device complexity is worsened

Engineering Contradiction:
Improveisophorone purityVSAvoidseparation process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The two-stage reaction process performs preliminary separation of by-products at the reaction stage itself, with the first stage minimizing by-product formation and the second stage completing conversion while maintaining selectivity. This preliminary action reduces the burden on downstream separation equipment

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The process discards minimal by-products through simple distillation while recovering and recycling unreacted acetone and intermediate products back into the reaction system. This approach achieves high purity with minimal separation complexity by focusing on what to keep rather than what to remove

Inventive Principle:
Principle #34Discarding and recovering

4Manufacturing precision

If water is removed from the reaction system to improve selectivity, then manufacturing precision is improved, but loss of substance is worsened

Engineering Contradiction:
Improveisophorone selectivityVSAvoidwater loss
Core Design Contradiction:
Manufacturing precisionVSLoss of substance

Solution Approach 1:

Water produced in the condensation reaction is separated from the reaction mixture and recovered through condensation and collection systems. This recovered water is then reused in the reaction system, eliminating waste while maintaining the selectivity benefits of controlled water management

Inventive Principle:
Principle #34Discarding and recovering

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 enhances the economic and ecological efficiency of isophorone production by minimizing unwanted by-products and maintaining high selectivity, with reduced water consumption and waste generation, and allows for continuous operation.

Implementation Method 1

Isophorone is produced via a catalyzed aldol condensation of acetone

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 2

Hydrolysis of the reaction mixture and separation into an organic and an aqueous fraction

Methodology Applied
Scientific EffectHydrolysis: Hydrolysis

Implementation Method 3

The essentially aqueous fraction is subjected to distillative work-up

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 4

forwarding of the vapors from the top of the apparatus for the distillative work-up into the hydrolysis apparatus

Methodology Applied
Scientific EffectCondensation: Condensation

Data Source

PatentEP2649032B1Method for producing isophorone
Publication Date: 2018.04.04 EVONIK OPERATIONS GMBH

AI summary

The invention relates to a method for producing isophorone by catalyzed aldol condensation of acetone as an educt, reprocessing the reaction product, hydrolyzing the product stream, and separating into an organic and an aqueous fraction, obtaining isophorone from the organic fraction, distillatively reprocessing the aqueous fraction, and feeding the vapors from the head of the distillative reprocessing apparatus into the hydrolysis apparatus.