Esterification Process Foaming Control via Dynamic Energy Input

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Solution Overview

Problem

Esterification processes face challenges such as foaming issues during the production of esters, which lead to reduced yield and product impurities, particularly in the esterification of monobasic acids like benzoic acid, and result in longer reaction cycle times due to the need for high pressures and excessive water formation.

Innovation Solution

A process where the energy input to the reactor is initially reduced to control foaming during the early stages of the reaction, with the catalyst added at a predetermined temperature above the initial mixture temperature, and then increased to speed up the reaction completion, using a stoichiometric excess of alcohol and maintaining pressure above atmospheric to minimize water vaporization and alcohol boil-off.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If high energy input is provided to speed up the reaction rate, then productivity is improved, but excessive foaming occurs leading to reduced yield and product impurities

Engineering Contradiction:
Improvereaction rateVSAvoidfoaming
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamic control of energy input by adjusting the heating rate based on reaction progress and foaming conditions. The energy input is increased when foaming is controlled and decreased when foaming becomes excessive, creating a dynamic balance between reaction rate and foaming suppression. This resolves the contradiction by making the energy input adaptive rather than static.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the parameter of energy input (heating rate) in response to foaming conditions. By monitoring foaming and adjusting the energy input parameter accordingly, the system can maintain high productivity when conditions permit while suppressing foaming when it becomes problematic, thus resolving the contradiction between reaction rate and foaming.

Inventive Principle:
Principle #35Parameter changes

2Loss of substance

If pressure is maintained above atmospheric to minimize water vaporization and alcohol boil-off, then loss of substance is reduced, but foaming issues worsen during the reaction

Engineering Contradiction:
Improvealcohol boil-offVSAvoidfoaming
Core Design Contradiction:
Loss of substanceVSObject-generated harmful factors

Solution Approach 1:

The patent dynamically adjusts pressure based on reaction conditions. Pressure is maintained above atmospheric during phases where minimizing alcohol boil-off is critical, but can be reduced when foaming becomes excessive. This dynamic pressure control resolves the contradiction by adapting pressure levels to current reaction needs rather than maintaining a fixed pressure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent employs periodic adjustments of pressure and energy input during the reaction process. By alternating between higher pressure (to reduce boil-off) and lower pressure (to control foaming), the system achieves both objectives over the course of the reaction, resolving the contradiction through time-dependent control.

Inventive Principle:
Principle #19Periodic action

3Object-generated harmful factors

If energy input is reduced to control foaming, then harmful factors are reduced, but reaction cycle time increases

Engineering Contradiction:
Improvefoaming controlVSAvoidreaction cycle time
Core Design Contradiction:
Object-generated harmful factorsVSLoss of time

Solution Approach 1:

The patent uses dynamic energy input control where the heating rate is adjusted in real-time based on foaming conditions. When foaming is under control, energy input is increased to maintain high reaction rates. When foaming becomes excessive, energy input is temporarily reduced. This dynamic approach resolves the contradiction by minimizing energy reduction only when necessary, thus limiting the impact on reaction cycle time while effectively controlling foaming.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent implements feedback control where foaming conditions are monitored and used to adjust energy input. This closed-loop control ensures that energy input is reduced only to the extent necessary to control foaming, and increased again when foaming is under control, thereby minimizing the overall impact on reaction cycle time while maintaining effective foaming suppression.

Inventive Principle:
Principle #23Feedback

4Reliability

If stoichiometric excess of alcohol is used to drive the reaction to completion, then conversion is improved, but foaming increases due to excessive water formation

Engineering Contradiction:
ImproveconversionVSAvoidfoaming
Core Design Contradiction:
ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The patent applies dynamic control of reaction conditions including energy input and pressure in response to water formation and foaming. By adjusting these parameters based on real-time monitoring of reaction progress and foaming, the system can tolerate higher alcohol excess ratios without proportionally increasing foaming problems, thus maintaining high conversion while controlling harmful effects.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes operational parameters (energy input, pressure, temperature profile) in response to the increased water formation from excess alcohol. By adjusting these parameters, the system can manage the foaming consequence of high alcohol excess while maintaining the conversion benefits, thus resolving the contradiction between conversion and 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 approach effectively reduces foaming, maintains reaction efficiency, and shortens the reaction cycle time by optimizing energy input and pressure management, resulting in higher yields and purer products without significant increases in reaction time.

Implementation Method 1

bringing the mixture to reaction temperature by providing an energy supply to the reaction to cause the mixture to react

Methodology Applied
Scientific EffectHeating: Heating

Implementation Method 2

initially the energy supply is controlled to reduce foaming

Methodology Applied
Scientific EffectFoaming: Foam

Implementation Method 3

maintaining pressure above atmospheric to minimize water vaporization and alcohol boil-off

Methodology Applied
Scientific EffectVaporization: Evaporation

Data Source

PatentEP2609068B1Processes for the production of esters
Publication Date: 2020.03.18 EXXONMOBIL CHEMICAL PATENTS INC
  • EP2609068B1 patent drawingFigure 1
  • EP2609068B1 patent drawingFigure 2
  • EP2609068B1 patent drawingFigure 3

AI summary

A process for production of C4 to C15 esters by the esterification of a carboxylic acid or anhydride with a C4 to C15 alcohol including forming a reaction mixture of the acid or anhydride and the C4 to C15 alcohol including a stoichiometric excess of the alcohol and bringing the mixture to reaction temperature by providing an energy supply to the reaction to cause the mixture to react wherein initially the energy supply is reduced to reduce foaming and optionally the energy supply is subsequently increased to enhance reaction time.