Esterification Reactor Using Static Mixing and Hot Alcohol Recirculation

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Solution Overview

Problem

Conventional melt-phase polyester production facilities face high capital, operational, and maintenance costs due to the use of complex and expensive mechanically agitated reactors, which also interfere with reaction flow patterns and reduce product conversion.

Innovation Solution

A process involving esterification in a shell-and-tube heat exchanger followed by further esterification in an unagitated reactor, with distillative separation and recirculation of the liquid products to enhance conversion without mechanical agitation, reducing costs and optimizing reactor volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If mechanically agitated reactors (CSTRs) are used for esterification, then mixing and heat transfer are improved, but device complexity and capital costs increase

Engineering Contradiction:
Improvemixing and heat transferVSAvoidmechanical agitators and control equipment
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent replaces mechanical agitation systems with a static mixer design that uses controlled flow patterns through packed beds and structured reactors. The mixing function is achieved through fluid dynamics and reactor geometry rather than mechanical agitators, eliminating moving parts while maintaining effective mixing and heat transfer

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention removes the mechanical agitator component entirely from the esterification reactor system. By extracting this complex mechanical element and replacing it with a static mixing approach using packed catalyst beds and controlled flow regimes, the system achieves the desired mixing and heat transfer without the complexity of mechanical systems

Inventive Principle:
Principle #2Taking out (Extraction)

2Use of energy by stationary object

If internal heat exchange tubes are added to CSTRs, then heat transfer is improved, but effective reactor volume decreases

Engineering Contradiction:
Improveheat transferVSAvoideffective reactor volume
Core Design Contradiction:
Use of energy by stationary objectVSVolume of moving object

Solution Approach 1:

The reactor design integrates multiple functions into the reactor structure itself. The reactor walls and internal geometry serve both as containment and as heat exchange surfaces, while the packed catalyst beds provide both catalytic activity and heat transfer media. This multi-functionality eliminates the need for separate internal heat exchange tubes that would displace reactor volume

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

Solution Approach 2:

The invention merges the heat exchange function with the reactor structure and catalyst support. The catalyst-packed beds serve dual purposes as both the reaction medium and the heat transfer medium, eliminating the need for separate heat exchange tubes that would reduce effective reactor volume

Inventive Principle:
Principle #5Merging (Combining)

3Manufacturing precision

If multiple CSTRs in series are used, then product conversion is improved, but capital and operating costs increase

Engineering Contradiction:
Improveproduct conversionVSAvoidnumber of reactors and control systems
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the reaction process into multiple functional zones within a single continuous reactor system. The segmented packed beds with different catalysts or conditions are arranged in series within one reactor, achieving the conversion benefits of multiple reactors while maintaining a single integrated system with reduced complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention combines multiple reaction stages that would traditionally require separate CSTRs into a single continuous reactor system. By integrating multiple catalytic zones and reaction conditions within one reactor vessel, the system achieves high product conversion while eliminating the need for multiple separate reactors and their associated control systems

Inventive Principle:
Principle #5Merging (Combining)

4Temperature

If internal heat exchange coils are added to CSTRs, then temperature control is improved, but flow patterns are interfered with and conversion is reduced

Engineering Contradiction:
Improvetemperature controlVSAvoidproduct conversion
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent implements localized heat exchange through the packed catalyst beds themselves, where heat transfer occurs locally at the reaction sites rather than through centralized internal coils. This distributed approach maintains temperature control without creating flow interference that would reduce conversion

Inventive Principle:
Principle #3Local quality

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 minimizes capital and operational costs while achieving high product conversion and efficient production of polyesters with reduced mechanical agitation and reactor volume, improving the overall efficiency of the polyester production process.

Implementation Method 1

subjecting at least a portion of the first vapor product to distillative separation in a distillation zone

Methodology Applied
Scientific EffectDistillation: Distillation

Implementation Method 2

esterification in a shell-and-tube heat exchanger

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP2089152B1Polyester production system employing recirculation of hot alcohol to esterification zone
Publication Date: 2013.09.18 GRUPO PETROTEMEX SA DE CV
  • EP2089152B1 patent drawingFigure 1

AI summary

A polyester production process employing an esterification system that uses a distillation column to recover alcohol produced from an esterification zone and then recirculates the recovered alcohol back to the esterification zone without substantially cooling the recovered alcohol.