Butyl Acrylate Purification via Thermal Cracking of Michael Adducts

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Solution Overview

Problem

Existing butyl acrylate manufacturing processes face challenges in obtaining high-purity products while minimizing the formation of difficult-to-separate byproducts and avoiding solid deposits, leading to significant yield loss and inefficient purification steps.

Innovation Solution

A catalyst-free thermal cracking process is implemented to transform Michael adducts, combined with a reactor for purging products from the bottom of the purification column, followed by recycling top products, to achieve high-purity butyl acrylate with reduced dibutyl ether content and increased productivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If catalyst-free thermal cracking is used to transform Michael adducts, then ester purity is improved (>99.5%), but process complexity increases due to additional reactor and purification steps

Engineering Contradiction:
Improveester purityVSAvoidprocess complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The purification process is divided into distinct segments: the thermal cracking reactor separates Michael adducts breakdown, followed by distillation columns for light by-products removal, and final purification steps. This segmentation allows each unit operation to target specific impurities, achieving >99.5% ester purity while managing complexity through modular design

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention extracts and removes specific harmful impurities at different stages: catalyst-free thermal cracking eliminates Michael adducts and polymerization inhibitors, while subsequent distillation removes light by-products like dibutyl ether (<500 ppm). This selective extraction approach achieves high purity without requiring complex multi-step treatments for all impurities simultaneously

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If multiple purification steps are implemented to remove heavy by-products, then product purity is improved, but productivity deteriorates due to time-consuming operations

Engineering Contradiction:
Improveproduct purityVSAvoidproductivity
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The catalyst-free thermal cracking step is performed preliminarily to break down Michael adducts and polymerization inhibitors into volatile components before distillation. This preliminary action prevents these heavy by-products from accumulating in subsequent purification steps, reducing the burden on distillation columns and accelerating the overall purification process while maintaining high product purity

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the thermal parameters by applying catalyst-free thermal cracking at elevated temperatures to selectively decompose heavy by-products like Michael adducts into volatile fragments. This parameter change transforms non-volatile impurities into volatile substances that can be efficiently removed in distillation, speeding up purification without compromising purity

Inventive Principle:
Principle #35Parameter changes

3Productivity

If catalyst-assisted cracking is used to treat heavy by-products, then reaction efficiency is improved, but solid deposits form in the reactor

Engineering Contradiction:
Improvereaction efficiencyVSAvoidsolid deposits
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The invention extracts the catalyst from the system by using catalyst-free thermal cracking. This removes the source of solid deposit formation while still achieving efficient breakdown of Michael adducts through pure thermal energy. The absence of catalyst prevents polymerization reactions that would otherwise create solid residues in the reactor

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention converts the potentially harmful high-temperature thermal cracking process into a beneficial catalyst-free operation. By using thermal energy alone without catalysts, the process avoids solid deposit formation while still achieving efficient decomposition of heavy by-products. The thermal energy that could cause unwanted side reactions with catalysts is instead used cleanly to break down impurities

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

4Ease of manufacture

If incineration is used to dispose of evaporator residue, then purification is simplified, but yield loss increases significantly

Engineering Contradiction:
Improvepurification simplicityVSAvoidyield loss
Core Design Contradiction:
Ease of manufactureVSLoss of substance

Solution Approach 1:

The invention changes the thermal treatment parameters by using catalyst-free thermal cracking at controlled temperatures to decompose Michael adducts into volatile products that can be distilled and recovered. This parameter change transforms the residue from incineration-worthy waste into recoverable material, reducing yield loss while maintaining purification effectiveness

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Instead of discarding the evaporator residue through incineration, the invention recovers valuable components by using thermal cracking to decompose Michael adducts into volatile fragments. These fragments are then recovered through distillation and can be recycled back into the process, significantly reducing yield loss while maintaining simplified purification

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

The process achieves high-purity butyl acrylate with specifications of ester purity greater than 99.5% and dibutyl ether content less than 500 ppm, while limiting the amount of residue to be removed, thereby enhancing process efficiency and yield.

Implementation Method 1

a catalyst-free thermal cracking process is implemented to transform Michael adducts

Methodology Applied
Scientific EffectThermal cracking: Pyrolysis

Implementation Method 2

The reaction mixture at the end of the reaction comprises butyl acrylate, residual acrylic acid, butyl acid sulfate, traces of sulfuric acid, and various impurities resulting from side reactions. This reaction mixture is then subjected to a neutralization and water washing step

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 3

the bottom stream of the topping column is subjected to a rectification column to separate: at the top the purified desired ester; at the bottom a stream containing heavy by-products, which is concentrated on a film evaporator

Methodology Applied
Scientific EffectEvaporation: Evaporation

Data Source

PatentEP4392399B1Improved method for producing high-purity butyl acrylate
Publication Date: 2026.01.14 ARKEMA FRANCE SA
  • EP4392399B1 patent drawingFigure 1

AI summary

The present invention relates to the production of butyl acrylate by direct esterification of acrylic acid with butanol, said reaction is catalysed by sulphuric acid. More specifically, the subject matter of the invention is an improved method for producing butyl acrylate, comprising a step of recovering the heavy by-products generated during said production, leading to a high yield of a product that meets the standards of purity and acidity under optimised energy conditions.