Continuous Transesterification Using Solid Acid Catalyst

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Solution Overview

Problem

Conventional batch processes for producing plant sterol and stanol esters face challenges such as excessive foaming, high catalyst consumption, long reaction times, and increased processing costs due to high temperatures and caustic conditions, leading to product degradation and reduced production capacity.

Innovation Solution

A continuous transesterification process involving a thin film evaporator where a reaction mixture of sterols and/or stanols with a fatty acid ester and catalyst is continuously fed, allowing for efficient removal of alkanol and reducing foaming, with optional recirculation and use of a pre-reactor unit to manage volatile compounds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a large amount of transesterification catalyst is added to achieve high esterification degree, then the requirement for commercial esterified plant sterols and/or esterified plant stanols is fulfilled, but the catalyst removal step becomes more challenging and processing costs increase

Engineering Contradiction:
Improveesterification degreeVSAvoidcatalyst removal
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the chemical parameter of the catalyst by using a solid acid catalyst instead of a caustic catalyst. This parameter change allows achieving high esterification degree (95% or higher) while avoiding the catalyst removal challenges associated with caustic catalysts, as solid acid catalysts can be easily separated by filtration and do not require complex neutralization and extraction steps

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs a solid acid catalyst that can be easily disposed of or regenerated after use. The catalyst is introduced in a form that facilitates its separation from the product mixture, and can be recovered by filtration or other separation methods, avoiding the need for complex catalyst removal procedures required by caustic catalysts

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

2Manufacturing precision

If batch processing is used to produce plant sterol ester and/or plant stanol ester with high degree of esterification, then commercial quality requirement is met, but long reaction time (2-20 h) exposes feed components to degradation

Engineering Contradiction:
Improveesterification degreeVSAvoidreaction time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent transitions from batch processing to continuous processing, where the transesterification reaction occurs continuously in a flow reactor. This continuous operation maintains optimal reaction conditions throughout, achieving high esterification degree (95% or higher) while significantly reducing the total reaction time compared to batch processing, thereby minimizing feed component degradation

Inventive Principle:
Principle #20Continuity of useful action

Solution Approach 2:

The patent changes the reaction mode parameter from batch to continuous, and also changes the catalyst type to solid acid. These parameter changes enable the reaction to proceed at higher rates with better control, achieving commercial quality requirements in shorter times and reducing thermal and chemical degradation of feed components

Inventive Principle:
Principle #35Parameter changes

3Productivity

If elevated temperature (100-130°C) and caustic environment are used in batch processing, then transesterification reaction proceeds, but feed components undergo degradation such as hydrolysis and isomerisation

Engineering Contradiction:
Improvereaction rateVSAvoidfeed component degradation
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the catalyst type parameter from caustic to solid acid, which fundamentally alters the reaction conditions. This parameter change allows the reaction to proceed at lower temperatures with reduced harmful effects on feed components, while maintaining acceptable reaction rates through the high activity of solid acid catalysts

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent converts the previously harmful caustic environment into a beneficial solid acid catalysis system. The solid acid catalyst provides the necessary catalytic activity without creating the harmful caustic conditions that cause feed component degradation, hydrolysis, and isomerisation, thereby turning a harmful process condition into a beneficial one

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

4Loss of substance

If vacuum is applied to remove methanol vapour during transesterification, then methanol is condensed and collected, but vigorous foaming occurs in the caustic reaction environment

Engineering Contradiction:
Improvemethanol removalVSAvoidfoaming
Core Design Contradiction:
Loss of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent changes the catalyst type parameter from caustic to solid acid, which eliminates the foaming problem. Solid acid catalysts do not create the highly basic conditions that cause vigorous foaming during vacuum methanol removal, allowing efficient methanol vaporization and condensation without product loss through foaming

Inventive Principle:
Principle #35Parameter changes

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 production throughput, reduces catalyst consumption, improves product quality, and decreases processing costs by shortening reaction time and minimizing product loss, while maintaining high degrees of esterification.

Implementation Method 1

The transesterification reaction is carried out by pumping the dried feed continuously and adding and preferably mixing a transesterification catalyst continuously in-line, transferring continuously the obtained reaction mixture of reactants and catalyst through a thin film evaporator operating at elevated temperature and low pressure

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 2

Methanol is removed as vapour from the reactor by vacuum and is condensed and collected at the vacuum system

Methodology Applied
Scientific EffectVacuum distillation: Vacuum Distillation

Implementation Method 3

adding a sufficient amount of a transesterification catalyst to the dried mixture. In the transesterification reaction plant sterol fatty acid ester and/or plant stanol fatty acid ester (often called only plant sterol ester and/or plant stanol ester) and methanol are produced

Methodology Applied
Scientific EffectCatalysis: Catalysis

Implementation Method 4

Methanol is removed as vapour from the reactor by vacuum and is condensed and collected at the vacuum system

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP2185673B1Transesterification process
Publication Date: 2018.02.14 RAISIO NUTRITION LTD
  • EP2185673B1 patent drawingFigure 1~2

AI summary

The invention relates to a process and a device for the preparation of a sterol and/or stanol fatty acid ester by a continuous transesterification process. The process comprises providing a dried feed mixture comprising a sterol and/or stanol (1) and an alkyl fatty acid ester (2), adding a transesterification catalyst (3) to the dried feed mixture to obtain a reaction mixture, continuously feeding the reaction mixture into a thin film evaporator (7) where the transesterification reaction takes place, continuously withdrawing alkanol (8) formed during the reaction from the thin film evaporator, and continuously recovering a sterol and/or stanol fatty acid ester product from the thin film evaporator, and removing (9) catalyst from the recovered product, and optionally refining (10) the recovered product.